PK4+d[d[refs.MYD @8 */( ke hazards; Engineeri f September 19, 1985 -- p D, approximately 45 br th little or no atten ted in its pre-event, damaged, and repaired conditions. Following the nonlinear static analysis procedure, displacement demands and capacities of the structure are used as indices o UHjor earthquake-initiated hazmat releases (EIHRs) has received little attention from esF?C4Youd, 5 5e Engineering Research Institute, 499 14th St, Suite 7 vF?m3Malilay, J. et al.,1995WMortality an O ng types in a similar manner to the engineering analysis of a single structure.32DF?2Shinozuka, Masanobu et al.,1997L M\generally exposed poorly stratified granular materials in which faults that were previously mapped on the surface were difficult to recognize. The age an }Mves not only from the advances made by individual investigators, but also from the innovations developed in synthesizing the  e to the tight coupling b UER) have focused on assessing seismic hazard and vulnerability in the Central United y<Loss estimation due to seismic risks to highway systemsEarthquake SpectraVol. 134, pp. 585-604. Nov.Highway sed; and a brief over 8(rizes the development her construction; United States; U.S. Army; Nonlinear response(A 1/3-scale model of a section of a three-story lightly reinforced concrete flat slab structure was constructed. Researchers installed a viscoelastic damper (VED) seismic rehabilitation system on the model and subjected it to seismic simulations on a shaking table. Successive simulations were conducted with increasing base accelerations until the horizontal displacement limit of the shaking table was reached. The dampers were then removed, and the simulations were repeated until structural failure occurred. This paper summarizes the responses of the model. Brief comparisons of the responses of the model with and without VEDs installed are made. The VEDs improved energy dissipation characteristics and serviceability of the structure by reducing interstory displacements. Earthquake simulation responses indicated that the damper configuration that was employed in the experimental investigation permitted rotations of the VEDs, which lowered their energy dissipation efficiency. An alternate arrangement for the VEDs is proposed to alleviate this problem.F?2!Razvi, Salim R. Saatcioglu, Murat19997Analysis and design of concrete columns for confinementEarthquake SpectraVol. 154, pp. 791-811. Nov.{Reinforced concrete columns; nonlinear analysis; Confined concrete columns; displacement-based design; Anchors (structural)jAn analytical procedure was developed to model formation and progression of flexural hinging in reinforced concrete columns. The procedure was employed to demonstrate second order inelastic analysis of concrete columns under monotonically increasing lateral loads. Other relevant features of inelastic column analysis were also incorporated, including concrete confinement, reinforcement strain hardening, bar buckling and anchorage slip. The analysis procedure has been verified extensively against experimental data, and used to illustrate a displacement-based design procedure for column confinement. Furthermore, a set of column analyses was conducted to develop design aids for column confinement. The amount, grade, spacing, and arrangement of confinement reinforcement can be selected from these design aids for expected levels of lateral drift and axial compression./ ?2Kunreuther, Howard1999hInsurance as an integrating policy tool for disaster management: the role of public-private partnershipsVol. 154, pp. 725-745. Nov.3Insurance; public policy; private sector; Contra Costa County; California; Santa Clara County; Los Angeles County; San Bernardino County; Building codes; Earthquake hazard mitigation; Northern California; Southern California; San Francisco Bay Area; United States; disaster planning; seismic risk assessmentCInsurance can play a key role in facilitating public-private partnerships for dealing with the losses from future natural disasters. This paper proposes a hazard management program, which links insurance with other policy tools and brings together key interested parties concerned with earthquakes. It stresses the importance of identifying and assessing the risk, understanding both the decision processes of individuals in hazard-prone areas and the insurability issues associated with the earthquake risk. A series of policy-related questions raise issues for future research. F?2Chapman, Martin C.1999>On the use of elastic input energy for seismic hazard analysisEarthquake SpectraVol. 154, pp. 607-635. Nov.[Linear oscillators; response and input energy; Ground motion; duration; Probabilistic seismic hazard analysis; Western North America; strong-motion records; Western United States; accelerograms; pseudorelative velocity response; Northridge; California earthquake; Jan. 17; 1994; Loma Prieta; Oct. 17; 1989; Southern California; Northern CaliforniaThe disaggregation of probabilistic seismic hazard calculations based on elastic input energy may prove useful for the identification of scenario events because input energy is a convenient single-parameter descriptor of motion duration and amplitude. To investigate this application, regression models are derived for the absolute input energy equivalent velocity, V subscript ea, and the elastic pseudo-relative velocity response, PSV, in the frequency range 0.5 to 10 Hz. Disaggregation of a general seismic hazard model using V subscript ea indicates that the modal magnitudes for the higher frequency oscillators tend to be larger, and vary less with oscillator frequency, than those derived using PSV. Larger magnitude earthquakes contribute more to seismic hazard if V subscript ea is used. The dependence of V subscript ea and PSV upon site classification is virtually identical, and V subscript ea can be predicted with slightly less uncertainty as a function of magnitude, distance and site classification.F?2#Husein Malkawi, Abdallah I. et al.,1999oApplication of extreme value statistics to annual maximum magnitudes in Jordan employing a mixture distributionEarthquake SpectraVol. 154, pp. 711-724. Nov.[Jordan; earthquake magnitudes; Middle East; Seismic risk; magnitude-frequency relationshipsThe concept of extreme value mixture distribution (EV subscript mix) has been implemented in this study to estimate maximum earthquake magnitude occurrence. The EV subscript mix model is applied to annual maximum earthquake magnitude occurrence in Jordan and conterminous regions spanning the period 1918 to 1997. The maximum likelihood method, in conjunction with the two optimization methods, was employed for determining the statistical parameters of the Gumbel asymptotic distribution, G superscript I, and the extreme value distributions, EV superscript III and EV subscript mix. The simplex method of Nelder and Mead was found to be more successful in obtaining the maximum likelihood estimators of the three given distributions than the Newton-Raphson method. The difficulties inherent in the Newton-Raphson method were overcome by the simplex method. It is shown in this study that the EV subscript mix model fits the observed annual maxima far better than the G superscript I and EV superscript III models. In addition, the maximum likelihood estimators obtained using the simplex method were used to calculate the earthquake risk for a given return period and design lifetime of structures.AF?20Dutta, Anindya Mander, John B. Kokorina, Tatiana19990Retrofit for control and repairability of damageEarthquake SpectraVol. 154, pp. 657-679. Nov.`Reinforced concrete bridge columns; nonlinear time history analysis; Fuse-bars; Renewable hinges-Collapse or severe damage of a large number of bridges in recent earthquakes in California and Japan has emphasized the need to develop a suitable retrofitting technique for enhancing the flexural ductility and shear resistance of existing bridge columns. However, most retrofit techniques currently in vogue are essentially one-time fixes that do not address the issue of repairability following a seismic event. This paper reports the results of a research program investigating the performance of reinforced concrete bridge columns where the main objective is to control damage and ensure fast rehabilitation with minimum disruption to the traffic flow. Thus a retrofit for control and repairability of damage (ReCARD) philosophy is developed and validated through experiments on near full-size bridge columns. F?2Ma, R. Xiao, Yan1999XSeismic retrofit and repair of circular bridge columns with advanced composite materialsEarthquake SpectraVol. 154, pp. 747-764. Nov.Circular bridge columns; nonlinear response; repairs; Prefabricated glass-fiber-reinforced polymer jacketing; Reinforced concrete bridge columns; hysteresis; California; older constructionExperimental studies on seismic retrofit and repair of typical circular bridge columns with poor lap splice details utilizing prefabricated glass fiber reinforced polymer (FRP) composite jackets and epoxy are presented in this paper. A total of seven tests on three 1/2-scale model columns were conducted. One column was tested under the "as-built" condition and the other two columns were retrofitted with prefabricated composite individual and continuous jackets, respectively. The jackets were applied in the potential plastic hinge region of the column to increase its lateral confinement. Brittle failure was observed in the "as-built" model column due to the bond deterioration of lap spliced longitudinal reinforcement. This brittle failure was prevented in the retrofitted columns. The repairing of the failed "as-built" column by injecting epoxy into the damaged plastic region resulted in significant stiffening of the portion and an increase in the capacity and ductility. The second repair of the specimen using both epoxy injection and prefabricated composite jacketing effectively improved its behavior further. The results of this study indicated that dramatic improvement in ductility and energy absorption capacity of columns can be achieved using these retrofit and repair methods.F?2Orsini, Giampiero1999hA model for buildings' vulnerability assessment using the Parameterless Scale of Seismic Intensity (PSI)Earthquake SpectraVol. 153, pp. 463-483. Aug.Italy; structural damage prediction; reinforced concrete structures; brick structures; Earthquake intensities; Loss estimation methodologies; Campania-Basilicata; Italy earthquake; Nov. 23; 1980; damage; Irpinia; Apartment buildings; vulnerability; Irpinia region$After the earthquake of 1980 in Irpinia, the Italian Government promoted a damage survey, with the cooperation of researchers of the Progetto Finalizzato Geodinamica, Consiglio Nazionale delle Ricerche PFG-CNR. The data of the damage survey has been used in several studies during previous years, and in the present work the studies have been elaborated on with the aim of assessing a value of the seismic excitation in each administrative unit according to the Parameterless Scale of Seismic Intensity (PSI). The PSI intensities are in good correlation with the values of the MSK scale: for each degree of the latter, the PSI intensity, a continuous variable, shows a spectrum of values. At the same time, a model for damage prediction has been identified, where the frequency of a damage degree in a territorial unit is a function of PSI. The proposed damage prediction model has been compared with the Damage Probability Matrix method and the range of variation of the losses evaluated in scenario analyses at the National Seismic Survey has been estimated.F?2Kim, Simon D'Amore, Enzo19996Push-over analysis procedure in earthquake engineeringEarthquake SpectraVol. 153, pp. 417-434. Aug.[Applied Technology Council (ATC); ATC-40; Capacity spectrum method; Static nonlinear pushover analysis; story drift; Burbank; California; multistory steel office buildings; Southern California; Hysteretic damping; Hyogoken-Nanbu earthquake; Kobe; Japan; Jan. 17; 1995; nonlinear time history analysis; roof drift; Northridge; California earthquakeThere has been an increasing trend toward the use of "push-over" analysis as a tool for evaluation of the safety of structures during earthquakes. A variety of existing push-over analysis procedures are currently being consolidated under programs such as ATC 40 and FEMA 273. This paper presents a critical review of the currently proposed push-over analysis procedure and a case study in which the proposed methodology is evaluated.FF?2Otani, Shunsuke1999IRC building damage statistics and SDF response with design seismic forcesEarthquake SpectraVol. 153, pp. 485-501. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; damage; Luzon; Philippines earthquake; July 16; 1990; Erzincan; Turkey earthquake; Mar. 13; 1992; Hyogoken-Nanbu earthquake; Kobe; Japan; Jan. 17; 1995; Lowrise reinforced concrete structuresEThis paper introduces the damage statistics of reinforced concrete buildings after the 1985 Mexico earthquake, the 1990 Luzon (Philippines) earthquake, the 1992 Erzincan (Turkey) earthquake, and the 1995 Hyogo-ken Nanbu (Kobe) earthquake. These data were obtained in severely damaged areas in each earthquake through the inventory damage investigation of the Architectural Institute of Japan teams. The damage statistics indicated severe damage in taller buildings and significantly less damage in lowrise buildings. A series of nonlinear single-degree-of-freedom systems having minimum code required lateral resistance were analyzed using the earthquake motions recorded near the areas of the damage surveys. Contrary to the statistics, the nonlinear response analysis( ?rez, V. Brady, A. G.1984lReversing cyclic elastic demands on structures during earthquakes and applications to ductility requirements6Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 11, pp. 7-32. Nov.TDuctility; Displacements (structural); Response spectra; nonlinear; linear; Nonlinear structures; strong-motion records; Elastoplastic analysis; Southern California; earthquakes; 1979; structural ductility; Imperial Valley; California earthquake; Oct. 15; Dynamic response; Deterministic methods; structural response; Engineering Seismology"The study of all earthquake-induced oscillator response peaks from selected records shows how these peaks decrease in amplitude with the number of cycles attained. These studies concentrate on the ratio between the peak amplitudes of response experienced throughout the duration of a given number of cycles and the maximum response. The ratio shows a trend that is fairly independent of the structure's period, the epicentral distance, and the earthquake magnitude. If during a very large earthquake, a structure is forced into displacements beyond the elastic limit, it must withstand them successfully with well-designed ductility. For long-period structures, these inelastic displacements, if assumed to result from idealized elastoplastic behavior, are approximately equal to the elastic displacements under study. The trends shown in this paper consequently indicate that the amplitudes of the elastoplastic displacements still attained after two, four, or eight cycles remain at levels that are appreciably high percentages of the maximum displacement.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23958Nkinson, G. M. Finn, W. D. L. Charlwood, R. G.1984NSimple computation of liquefaction probability for seismic hazard applications6Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 11, pp. 107-123. Nov.Liquefaction; computer applications; Earthquake hazards; Probability theory; Sands; Soils; Sites; Canada; PROLIQ; Nondeterministic methods; Soil; Foundation DynamicsA computer program has been written for the routine calculation of the probability of seismically induced liquefaction for level sand or silty sand sites. The method combines Seed's simplified method of assessing liquefaction potential with the Cornell method of assessing seismic hazard by modifying the latter to consider the joint probability of magnitude and acceleration. The input data to the program are simple geotechnical data from SPT, CPT, or laboratory tests and readily obtainable regional seismicity data.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395T*| for structural design or for estimating structural vulnerabilit`NU$ masonry structures; design; San Francisco; earthquake; 1906; Reinforcement; masonry structures; Northern California; Earthquake-Resistant DesignAlthough the reinforcement of masonry buildings against earthquake damage was known as early as 1755, it only came of age in the United States in the late 1930s. This survey, which includes seismic-resistant construction systems dating from 1755, 1783, 1784, 1854, 1870, 1872, 1906, and 1907, illustrates how common sense solutions for the reinforcement of masonry buildings had already been invented and used long before the 1933 Long Beach earthquake which stimulated modern reinforcement research.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 ?081 Arnold, C.1984;Planning against earthquakes in the United States and Japan6Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 11, pp. 75-88. Nov.Japan; disaster planning; United States; California; Southern California; Earthquake hazards; mitigation; Legislation; Governmental aspects; Earthquakes as Natural DisastersComprehensive earthquake disaster preparedness planning encompasses two distinct but related elements: emergency planning and hazard mitigation. The UniXOign charts are presented, and an example of their use on a 12-story structure is detailed.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23950N84DGlossary of terms for probabilistic seismic-risk and hazard analysis6Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 11, pp. 33-40. Nov.qSeismic risk; Earthquake hazards; Seismic microzoning; Seismic zoning; Return periods; Glossaries; General TopicsIn 1977, the EERI Committee on Seismic Risk was assigned the task of developing a terminology in the form of a glossary of terms of probabilistic seismic hazard and risk analysis methods. The proposed glossary was first developed between 1977 and 1982. During that period, the proposal went through various reviews by the committee and the membership of EERI. In 1981, a draft of the present glossary was published in the EERI Newsletter and the resulting comments from the readers have been incorporated in the document presented here.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395?Dl71 Tobriner, S.1984VA history of reinforced masonry construction designed to resist earthquakes: 1755-19076Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 11, pp. 125-149. Nov.United StPIj`or estimating structural vulnerabilities to reconcile earthquake-related damage.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23954DlU$85Structural moments I6Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 12, pp. 353-388. Feb.Story drift; Cracking; concrete; Steel frames; design; frames; Wood; Wind loads; building codes; Welding; Reinforcing steel; Structural DynamicsaSix articles are republished, with some revisions, from the Structural Engineers Assn. of Northern California's publications on technical topics of interest to the structural engineer practicing in a highly seismic area. The articles are the following: Drift limits: are they realistic, by S. A. Freeman; Shrinkage of lumber: a way to fight a knotty problem, by D. L. Messinger; Background of current wind provisions, by W. L. Casper; Thoughts on welding reinforcing steel, by L. W. Mattis; Concrete cracking: where do we go from here?, by F. R. Preece; A response of PCA on concrete cracking, by R. E. Tobin.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395DlXiu, A. N. L. et al.,1984CDamage survey of the Kaoiki, Hawaii earthquake of November 16, 19836Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 11, pp. 173-195. Nov.Hawaii; earthquakes; 1983; Residential buildings; damage; Lifeline systems; Electric power distribution; Water supply systems; Telecommunications systems; Transportation systems; Foundations; Highways; Isoseismal maps; Hawaii earthquake; Earthquake Damage$Following the earthquake, the Earthquake Engineering Research Inst. and the American Society of Civil Engineers appointed a task committee to survey the damage. This report documents representative damage and offers constructive suggestions to mitigate future damage from similar earthquakes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395U$I51Mayes, R. L. et al.,1984EDesign guidelines for base-isolated buildings with energy dissipators6Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 11, pp. 41-74. Nov.Base isolation; building codes; Energy dissipation; Multistory structures; Rubber bearings; Uniform Building Code; Ductility; Braced frames; Steel frames; Applied Technology Council; design criteria; Bearings; Earthquake-Resistant DesignThis paper provides the basis of a practical base isolation system which includes energy dissipation in special purpose mechanical devices. Topics covered include basic elements of base isolation, feasibility, design philosophy, and code considerations. Design procedures based onTj`qF?4Rojahn, C. et al.,19864Earthquake damage and loss evaluation for CaliforniaEarthquake SpectraVol. 24, pp. 767-782. Oct.ZCalifornia; structural damage prediction; Residential buildings; damage prediction; Industrial plants; Public utilities; Lifeline systems; Transportation systems; Businesses; Bridges; Dams; Economic analysis; Socioeconomic aspects; United States; U.S. Federal Emergency Management Agency; Agriculture; Ground motion; Seismic safety; Braced framesConsensus-opinion earthquake damage and loss estimates and companion loss estimation and inventory methodology have been developed for existing facilities in California. Data and methodology developed include: consensus-opinion damage-factor estimates (expected physical damage due to ground shaking); methodology to adjust damage-factor estimates to account for construction quality; methodology to estimate the effects of collateral hazards such as ground failure, fault rupture, and inundation; loss-of-function data and methodology to estimate the time it takes to restore damaged facilities to their pre-earthquake usability; methodology to estimate deaths and injuries; and inventory data and methodology for all types of existing industrial, commercial, residential, utility, and transportation facilities in California. Damage-factor estimates are provided in the form of damage probability matrices for modified Mercalli intensities VI through XII. Seven damage states are considered. Loss-of-function estimates, which specify the time required to restore a facility to 30 percent, 60 percent, and 100 percent of the pre-earthquake usability, are provided for the damage states.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4McDonough, P. W. Taylor, C. E.1986.Assessing seismic response of Utah gas systemsEarthquake SpectraVol. 24, pp. 747-765. Oct.Utah; gas supply systems; Public utilities; Seismic safety; Earthquake hazards; Lifeline systems; Seismic risk; Pipelines; damage prediction; Liquefaction; Earthquake DamageThe potential damage to lifelines from even moderate earthquakes can have significant and widespread effects on community well-being. Recently, under the sponsorship of the U.S. Geological Survey, researchers from California cooperated with a utility in Utah to analyze the seismic safety of natural gas facilities in Utah. They identified pipelines by system importance, size, and material, and then assessed the probability of structural damage to these components. These estimates, which reflect knowledge of Wasatch Front fault mechanisms and an ability to model numerous seismic events by computer, are yielding significant knowledge of possible piping responses.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395nF?4Porcella, R. L. Huang, M. J.1986Strong motion reportsEarthquake SpectraVol. 24, pp. 859-866. Oct.Strong-motion records; earthquakes; 1985; 1986; Seismicity; Eastern California; Southern California; Central California; San Francisco Bay Area; Union of Soviet Socialist Republics; Algeria; Nicaragua; Peru; India; Mexico; Turkey; Aleutian Islands; Alaska; Taiwan;These reports contain general information about strong-motion recordings recovered from worldwide stations and reported to the Earthquake Engineering Research Inst. from October 1985 through July 1986. The strong-motion earthquakes are listed, and strong-motion information is presented for 7 of the 20 earthquakes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395"F?4 Paulay, T.1986TThe design of ductile reinforced concrete structural walls for earthquake resistanceEarthquake SpectraVol. 24, pp. 783-823. Oct.Reinforced concrete walls; design; Reinforced concrete shear walls; Multistory structures; Strength; Ductility; Coupling; walls; United States; building codes; New Zealand; Reinforcement; Earthquake-Resistant DesignIn the design of reinforced concrete multistory buildings in which lateral load resistance has been assigned to structural walls, the emphasis should be on a rational strategy in the positioning of walls and the establishment of a hierarchy in the development of strengths to ensure that, in the event of a large earthquake, brittle failure will not occur. The preferred mode of energy dissipation should be flexure in a predictable region. Therefore, failures due to diagonal tension or compression, crushing of concrete in compression, sliding along construction joints, instability of wall elements or reinforcing bars, and breakdown of anchorages should be suppressed. These aims may be achieved by application of a deterministic design philosophy and special detailing and dimensioning of potentially plastic regions of walls is necessary. Differences exist between the code provisions and practices in the United States and New Zealand in several areas of design for reinforced concrete structural walls.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395GF?4Jephcott, D. K.1986M50-year record of Field Act seismic building standards for California schoolsEarthquake SpectraVol. 23, pp. 621-629. MayLateral loads; school buildings; Cost analysis; damage prediction; design standards; California; legal aspects; Earthquake hazards; Earthquake-Resistant DesignRThe results of more than 50 years' experience with enforcement of building standards for the construction of public school buildings in the State of California are described. The Field Act, which became effective Apr. 10, 1933, has the stated purpose of providing earthquake-resistant facilities for the safety of the occupants and protection of the state property. The performance of Field Act school buildings subjected to high-intensity ground motion from five earthquakes of the moderate to major range is provided as evidence of the effectiveness of this seismic hazard ed for the assessment of cumulative damage in structural steel components subjected to cyclic inelastic loading histories of the type experienced in earthquakes. The methodology is based on low-cycle fatigue concepts and the hypothesis of linear damage accumulation. It is shown that seismic performance of a component depends on two structural performance parameters and on the number and amplitudes of all inelastic excursions and not only on the maximum excursion. Experimental and analytical procedures for obtaining the parameters needed for a performance assessment are suggested.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Filiatrault, A. Cherry, S.1987^Performance evaluation of friction damped braced steel frames under simulated earthquake loadsEarthquake SpectraVol. 31, pp. 57-78. Feb.Friction; damping devices; frames; dynamic properties; Damping; Braced frames; nonlinear response; Shaking table tests; Cyclic loads; Time history analysis; Energy dissipation; Joints; Hysteresis; Structural Dynamics@This paper presents the results obtained from tests of a new friction damping system, which has been proposed to improve the response of steel moment-resisting frames (MRF) and braced moment-resisting frames (BMRF) during severe earthquakes. The system consists of a mechanism containing brake lining pads introduced at the intersection of frame cross braces. Seismic tests of a three-story friction damped braced frame (FDBF) model were performed on an earthquake simulator table. The experimental results are compared with the findings of an inelastic time history analysis.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395_ F?4 Greene, M. R.1987Skopje, Yugoslavia: seismic concerns and land use issues during the first twenty years of reconstruction following a devastating earthquakeEarthquake SpectraVol. 31, pp. 103-117. Feb.Yugoslavia; reconstruction; Land use; Urban and regional planning; Residential buildings; Design; legislation; Earthquakes as Natural Disasters; Governmental Aspects'This paper identifies some of the early decisions made in Skopje after the 1963 earthquake and illustrates how those decisions shaped the city's reconstruction. The formation of a guiding committee, and a massive influx of outside aid contributed to a careful, thoughtful reconstruction process.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Liu, S. C. et al.,1987SSummary of a visit to U.S.S.R. on seismic construction: U.S. delegation trip reportEarthquake SpectraVol. 31, pp. 79-89. Feb./United States; U.S.-U.S.S.R. exchange; Union of Soviet Socialist Republics; research; structural design; U.S.S.R.-U.S. exchange; Ground motion; Design; Dynamic analysis; Geotechnical engineering; Experimentation; Repairs; Shaking table tests; Damping devices; Stability; panel structures; General TopicsThe U.S.-U.S.S.R. Agreement on Housing and Other Construction was signed in Moscow, June 28, 1974, and includes a working group on Construction in Seismic Areas. As part of this protocol, exchange visits have occurred of working groups from the U.S. and the U.S.S.R. This report describes the most recent exchange during Oct. 12-22, 1986. The U.S. delegation visited construction sites and research institutes in Moscow, Tbilisi (Georgia), and Yerevan (Armenia). The technical focus of the visit was on structural analysis and design, ground motion and geotechnical engineering issues, and experimental studies in design, repair, and retrofit.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395DF?4SEAONC, 1987Structural momentsEarthquake SpectraVol. 31, pp. 175-207. Feb.$Cyclic loads; structural members; design; Hospitals; San Fernando; California earthquake; Feb. 9; 1971; Ground motion; structural design; Applied Technology Council; ATC 3-06; P-delta effects; Steel frames; dynamic properties; Multistory frames; Legal aspects; Multistory structures; analysis Four articles are republished, with some revisions, from the Structural Engineers Assn. of Northern California's occasional publications on various technical topics of interest to the structural engineer practicing in a highly seismic area. The titles and authors follow: Need improvements in structural design, by Larson, M. A.; A study of the P-delta effect, by Degenkolb, H. J.; A great dilemma--overstamping, by Diekman, E. F.; and Modeling variations in spectrum response calculation, by Maison, B. F. and Neuss, C. F.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Porcella, R. L.1987Strong ground motion reports6Earthquake Spectra, %WEarthquake Engineering AbstractsVol. 31, pp. 209-213. Feb.Romania; earthquakes; 1986; Greece; El Salvador; Yugoslavia; Taiwan; Bulgaria; San Salvador; El Salvador earthquake; Oct. 10; Engineering SeismologyThis report contains preliminary general information about strong ground motion recordings that have been recovered from worldwide stations and reported to the Earthquake Engineering Research Inst. between August 1986 and January 1987.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Gori, P. L. Greene, M. R.1987mThe influence of national attention on long-term earthquake preparedness policy in Charleston, South CarolinaEarthquake SpectraVol. 31, pp. 91-101. Feb.Charleston; South Carolina; disaster planning; Public policy; Socioeconomic aspects; Earthquakes as Natural Disasters; Governmental AspectsThe Charleston area offers a unique opportunity to study the implementation of policy for long-term earthquake preparedness at the local level. Interviews of public officials and others documented the low state of preparedness in 1981 and an improved situation in 1986. Since 1981, increased national attention has been used by citizens of the Charleston area to overcome political, informational, social, organizational, and economic barriers that retard the implementation of policies to mitigate the damage caused by earthquakes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Bertero, V. V.1986Lessons learned from recent earthquakes and research and implications for earthquake-resistant design of building structures in the United StatesEarthquake SpectraVol. 24, pp. 825-858. Oct./United State + teresis; structural damage prediction; Energy dissipation; Reinforced concrete frames; design; Damage; prediction; Reliability; Earthquake-Resistant DesignA procedure for earthquake-resistant design is developed to limit the potential damage of buildings to a tolerable level. The procedure is based on a damage model developed earlier by Park and Ang in which structural damage is expressed as a function of the maximum deformation and dissipated hysteretic energy. The tolerable degree of damage is defined based on calibration with observed damage from past major earthquakes. The design method is examined in the context of reliability.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4(Popov, E. P. Kasai, K. Engelhardt, M. D.19871Advances in design of eccentrically braced framesEarthquake SpectraVol. 31, pp. 43-55. Feb.Braced frames; nonlinear response; design; Hysteresis; frames; Beam-column joints; Links; Joints; bracing; Eccentric bracing; Ductility; Energy dissipation; Steel frames; Earthquake-Resistant DesignThe different types of eccentrically braced frames are critically evaluated, and the kinematics of their inelastic deformation are examined with particular reference to the behavior of short beam segments or links. Desirable link length and web stiffening are recommended. A preliminary design procedure for hand calculation of eccentrically braced frames is described and suggestions for brace connection details are advanced.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395ES F?4Krawinkler, H.1987*Performance assessment of steel componentsEarthquake SpectraVol. 31, Mar. 1987, 22-29.Low-cycle fatigue; steel members; damage prediction; analysis; nonlinear response; Cyclic loads; Experimental methods; Experimentation; Deterministic methods; Earthquake DamagebA methodology is presentF?4Abrahamson, N. A. et al.,19875The SMART I accelerograph array (1980-1987): a reviewEarthquake SpectraVol. 32, pp. 263-287. MayTaiwan; strong-motion instrument arrays; Seismicity; Tectonics; Time histories; Taiwan earthquakes; SMART-1; Linear systems; ground motion; Response spectra; Soil conditions; Waves; Acceleration; Strong Motion Seismometry SMART I, the first large digital array of strong-motion seismographs specially designed for engineering and seismological studies, is described. The array has recorded over 3000 accelerogram traces from 48 earthquakes ranging in local magnitude (M subscript L) from 3.6 to 7.0 since 1980.IF?4 Wang, M. L.1987/Cladding performance on a full-scale test frameEarthquake SpectraVol. 31, pp. 119-173. Feb./Cladding; response; United States; building codes; U.S.-Japan cooperative research; Japan; Japan-U.S. cooperative research; Joints; Concrete; panels; Ductility; connections; Precast concrete; Glass fibers; Reinforced concrete; Uniform Building Code; Story drift; Nonstructural systems; Secondary systemsThe last phase of the U.S.-Japan Cooperative Research Program's full-scale steel structure tests concerns the seismic performance of nonstructural or extrinsic elements. Both Japanese and U.S. elements were installed onto the full-scale, moment-resistant frame. Static tests of the frame with cladding and internal elements were conducted in Japan. The U.S. test focused on cladding, and the Japanese oversaw testing of cladding common to Japanese practice and internal partitions and ceilings common to both U.S. and Japanese practice. This paper describes findings of U.S. cladding performance tests with regard to values of seismic story drift designated in the Uniform Building Code and observations of the behavior of Japanese elements.Earthqu eration; Reinforced concrete structures; damage; Ground motion; Seismicity; Masonry structures; Response spectra; Apartment buildings; Houses; School buildings; Humans; Socioeconomic aspects; Earthquake DamagezThe earthquake, although of moderately strong reported magnitude (M subscript s = 6.2), caused heavy damage and killed 20 people. Strong-motion data are presented for the main event as well as from two recordings of the major aftershock. The records were obtained close to the epicenter. The soil profile at the recording site is given. Very high spectral accelerations characterize the records and are partly responsible for the total or partial collapse of seven modern reinforced concrete buildings. A survey of damage is presented with comments on its causes in relation to seismic regulations and to local construction practices.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 eering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395*lF?4$Park, Y. J. Ang, A. H. S. Wen, Y. K.1987,Damage-limiting aseismic design of buildingsEarthquake SpectraVol. 31, pp. 1-26. Feb.Reinforced concrete structures; damage prediction; Hys jn full-scale and large model dynamic testing based on a popular series of microcomputer has been developed. "Quick-look" and preliminary frequency analysis of data are completed in the microcomputer environment, while more detailed frequency domain analysis of single and dual channel data are completed in the main frame environment. The system has been used for ambient and forced vibration testing of several prototype structures and large models.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Hanson, R. D. Martin, H. W.1987MPerformance and steel structures in the September 19 and 20, 1985 earthquakesEarthquake SpectraVol. 32, pp. 329-346. MayMexico City; steel structures; damage; Building codes; Steel frames; Tall buildings; Steel columns; Soil conditions; structural damage; Earthquake DamageA description of the various types of steel structures built in Mexico City includes comparisons of the older types of steel construction with more modern buildings. Performance of steel buildings in the September 1985 earthquake was related to the local geotechnical conditions including foundation behavior. The collapses of the Edificio 21 Atlas and Conjunto Pino Suarez buildings raise important earthquake-resistant design and research issues.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395S F?41Thenhaus, P. C. Perkins, D. M. Algermissen, S. T.1987`Earthquake hazard in the eastern United States: consequences of alternative seismic source zonesEarthquake SpectraVol. 32, pp. 227-261. MayGround motion; United States; eastern; Attenuation; Eastern United States; earthquake hazards; Massachusetts; acceleration; Maine; North Carolina; Appalachian region; Canada; Seismicity; Tectonics; Probability theory; Engineering SeismologyThe regional variability in expected ground motion associated with six different characterizations of seismic source zones for probabilistic ground motion assessment is examined. Three of the seismic source zone models are based on types of geologic structure: (1) regions characterized by late-Precambrian faulting; (2) middle-to-late Paleozoic thrust tectonics; and (3) early-to-middle Mesozoic extensional features. Two other seismic source zone configurations considered are based on data related to vertical crustal movements, and the final source zone model investigated is that of Algermissen and others. Results are compared among source zone models for calculated acceleration levels in eastern Massachusetts, southeastern Maine, the Cape Fear arch of eastern North Carolina, other eastern seaboard areas, and the Appalachian region extending from New Brunswick to the Gulf Coast, maintaining the same maximum magnitude among all zones and for all source zone configurations.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395|F?4Wilson, E. L. Habibullah, A.1987PStatic and dynamic analysis for multi-story buildings, including P-delta effectsEarthquake SpectraVol. 32, pp. 289-298. MayuAlgorithms; multistory structures; P-delta effects; Computer programs; Static analysis; analysis; Structural DynamicsAn algorithm is developed that incorporates the P-delta effects into the basic formulation of the structural stiffness matrix as a geometric stiffness correction. This procedure can be used for both static and dynamic analysis and accounts for the lengthening of the structural time periods and changes in mode shapes due to P-delta effects. The algorithm can be directly incorporated into building analysis programs.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395dF?4Celebi, M. et al.,19874The culprit in Mexico City--amplification of motionsEarthquake SpectraVol. 32, pp. 315-328. MayMexico City; ground motion; Amplification; Mexico; earthquakes; 1985; geologic conditions; Maps; Soil conditions; Guerrero-Michoacan; Mexico earthquake; Sept. 19; Earthquake DamagepMexico City has repeatedly suffered from long-distance effects of earthquakes originating as far away as the subduction trenches near the Pacific Coast. The earthquake of Sept. 19, 1985, was no exception, causing extensive loss of life and property. Unique subsurface conditions resulting from the historical lakebed have distinct resonant low frequencies around 0.5 Hz. Strong earthquake motions from long distances as well as locally originating weak motions cause large amplifications at resonant low frequencies in the subsurface environment. The resonant frequencies and associated amplification of motions in Mexico City are quantified in terms of spectral ratios using Sept. 19, 1985, strong-motion data and weak motions recorded in January 1986. These ratios confirm that amplification of motions at resonant frequencies due to subsurface conditions is indeed the culprit.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395:DF?4Anagnostopoulos, S. A. et al.,1986/The Kalamata, Greece earthquake of September 13Earthquake SpectraVol. 32, pp. 365-402. May$Greece; earthquakes; 1986; building codes; Accelerograms; Greece earthquakes; Accel x9 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Olson, R. A.1987GThe San Salvador earthquake of October 10, 1986 -- overview and contextEarthquake SpectraVol. 33, pp. 415-418. Aug.El Salvador; earthquakes; 1986; structural damage; Casualties; San Salvador; El Salvador earthquake; Oct. 10; damage; Earthquake Damage'This paper presents a brief overview of the earthquake and its effects on the population and economy of El Salvador, including casualty and damage estimates. Preliminary conclusions reached by an EERI reconnaissance team that spent five days in El Salvador following the earthquake are outlined.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23956F?4 Fujii, T. Egawa, K. Katayama, I.1987UDynamic behavior of Nagawado arch dam in the event of 1984 Nagonoken Seibu earthquakeEarthquake SpectraVol. 32, pp. 347-364. MayArch dams; dynamic properties; Acceleration; dams; Japan; Displacements (structural); Finite element method; Interaction; foundation-dam; Fourier analysis; Earthquake DamageNagawado Dam, a slender arch dam of 155 m height and 355.5 m chord length, recorded maximum accelerations of 193 and 242 gal at the crown and the 1/4 point of the crest arch, respectively, in the Sept. 14, 1984, Nagonoken Seibu earthquake of magnitude 6.8. The maximum accelerations in the foundation rock were in the range of 21 to 31 gal. Analysis of the computed displacements of the dam and the foundation indicates significant structural modes of peak frequencies 3.3, 3.6, 4.7, and 5.5 Hz. These frequencies correspond to the antisymmetric first, the symmetric first, the symmetric second, and the antisymmetric second modes of the dam. The first three peak frequencies were in good agreement with the values obtained by a small-scale model test. The derived frequencies and vibration modes were also compatible with the results of a preliminary three-dimensional finite element model. Orthogonal sets of accelerograms recorded at the points across a treated fracture zone on the foundation rock did not record any significant relative motions.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395W?F?4Lin, A. N. Verser, B. A.1987?Microcomputer based data acquisition system for dynamic testingEarthquake SpectraVol. 32, pp. 299-313. May~Microcomputer applications; experimental methods; Ambient vibration tests; Forced vibration tests; Design; Structural DynamicsA data acquisition and analysis system for use i Ifacilities (hydroelectric and geothermal) that supply electricity to San Salvador are located too far from the city to have been affected by the earthquake. Both 115-kV substations that serve San Salvador suffered moderate damage, consisting mostly of ceramic column circuit breaker failures. Control and instrumentation systems and low-voltage power-supply equipment were able to withstand high ground accelerations.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Durkin, M. E. Hopkins, J.1987RThe San Salvador earthquake of October 10, 1986 -- architecture and urban planningEarthquake SpectraVol. 33, pp. 609-620. Aug.)El Salvador; earthquakes; 1986; Urban and regional planning; Residential buildings; damage; Hotels; Reconstruction; Land use; Nonstructural elements; Architectural systems; Commercial structures; San Salvador; El Salvador earthquake; Oct. 10; Earthquakes as Natural Disasters; Governmental Aspects The major damage from the earthquake concentrated in and around the capital city of San Salvador is described. Losses exceeded 900 million dollars, or 25 percent of El Salvador's 1986 gross domestic product. Poor soil conditions, ineffective land use controls, and inadequate building practices combined with the severe shaking intensity are implicated in widespread damage to engineered and nonengineered structures. Residential, institutional, and commercial buildings sustained heavy damage. Nonstructural damage and damage to building contents contributed to economic and operational loss. The attempts of government officials to incorporate new knowledge in reconstruction planning and the difficulties attending recovery and reconstruction due to the current state of the economy are described.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395GF?4Anderson, R. W.1987LThe San Salvador earthquake of October 10, 1986 -- review of building damageEarthquake SpectraVol. 33, pp. 497-541. Aug.,El Salvador; earthquakes; 1986; Lowrise structures; damage; Dynamic properties; structural damage; Collapse; El Salvador earthquakes; Hospitals; Tall buildings; Columns; Coupled shear walls; School buildings; Steel structures; Masonry structures; Hotels; Reinforced concrete columns; Low-cost housing2Heavy and widespread damage to lowrise engineered buildings in the three- to six-story height range is descri rr 10, 1986 -- processed strong motion dataEarthquake SpectraVol. 33, pp. 465-481. Aug.El Salvador; earthquakes; 1986; Accelerograms; El Salvador earthquakes; Time histories; Response spectra; San Salvador; El Salvador earthquake; Oct. 10; Engineering SeismologyStrong-motion records were recovered from nine accelerographs at seven stations of the El Salvador Geotechnical Investigation Center Strong Motion Network following the damaging 5.4 M subscript s earthquake. The sites were all within 6 km of the epicenter; peak horizontal accelerations at ground level ranged from 0.32 to 0.72 g. The duration of strong shaking was about 3 sec at most sites. One 10-story concrete building was instrumented with recorders at the basement, second floor, and roof level. The maximum accelerations recorded at this building are given. Eight of the accelerograms were digitized and processed. Maximum horizontal velocity for a station 4 km from the epicenter and peak velocity for the other stations are also given, along with the maximum horizontal displacements. The San Salvador records and spectra are compared to other close-in observations such as the Station 2 record from the ML 5.6 Parkfield earthquake of 1966.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395aF?4Morgan, J. R. Swan, S. W.1987KThe San Salvador earthquake of October 10, 1986 -- performance of lifelinesEarthquake SpectraVol. 33, pp. 585-607. Aug.El Salvador; earthquakes; 1986; Lifeline systems; damage; Water supply systems; Electric power distribution; Telecommunications systems; Racks; Circuit breakers; Equipment; San Salvador; El Salvador earthquake; Oct. 10; Earthquake DamageThe earthquake was a moderate (M = 5.4) event and the recorded ground motions had a relatively short duration; however, high recorded peak accelerations caused substantial damage to lifelines, including significant and widespread damage to buried lifelines. Long-distance telecommunications facilities appeared undamaged, but substantial loss of local phone service caused by damage to buildings, failures of equipment racks, and loss of emergency power (tilting of batteries) is reported. Power generating sVF?4 Sauter F, F.1987OThe San Salvador earthquake of October 10, 1986 -- structural aspects of damageEarthquake SpectraVol. 33, pp. 563-584. Aug.El Salvador; earthquakes; 1986; Multistory structures; damage; Loads; structural failure; Design; Nonstructural elements; Apartment buildings; Hospitals; School buildings; Hotels; Masonry structures; Lateral loads; Nonlinear response; San Salvador; El Salvador earthquake; Oct. 10The earthquake caused extensive damage to one- and two-story bahareque-type dwellings and buildings and the collapse of multistory engineered structures. Results of a study of the earthquake effects indicate that poor quality materials and workmanship, as well as deficiencies in construction details, helped cause severe damage while conceptual errors in design, including the selection of lateral load resistant systems, are implicated as the main cause of structural failure of buildings and engineered structures.Earthquake Engineering Research Institute, 49k%F?4&White, R. A. Harlow, D. H. Alvarez, S.1987jThe San Salvador earthquake of October 10, 1986 -- seismological aspects and other recent local seismicityEarthquake SpectraVol. 33, pp. 419-434. Aug.San Salvador; El Salvador earthquake; Oct. 10; 1986; El Salvador; earthquakes; Aftershocks; El Salvador earthquakes; Seismicity; SeismologyUThe earthquake originated along the Central American volcanic chain within the upper crust of the Caribbean plate. Results from a local seismograph network demonstrate a tectonic-type main shock-aftershock sequence, with a magnitude of 5.6. The hypocenter was located 7.3 km below the south edge of San Salvador. The main shock ruptured along a nearly vertical plane toward the north-northeast. A main shock fault-plane solution is given. For a previous volcanic chain earthquake which shook San Salvador on May 3, 1965, six foreshocks are located showing a distinctly WNW-trending distribution. Together with the distribution of damage and a fault-plane solution, these suggest that right-lateral slip occurred along a fault sub-parallel with the Central American volcanic chain, possibly the first time such motion has been documented along the chain.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 m'bed. Examples are cited of collapsed or partially collapsed buildings. Buildings that performed well are also reviewed. Lessons learned or relearned from the San Salvador earthquake are summarized.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 Dslide development during the earthquake and may have amplified ground motion. Faults mapped in the area strike east-west, northwest-southeast, and less distinctly, northeast-southwest, and north-south. Ringlike structures formed by volcanic subsidence are described in the area. No evidence was seen of surface faulting associated with the October 10 main shock or an earthquake on October 13 on a separate fault 7 km west-northwest of the main shock. Numerous cracks seen in the epicentral area of both earthquakes are explained as secondary ground failures. Both of the earthquakes occurred on unmapped faults. Landslides caused by the main shock are described along with rock falls and slides, slumps, rapid soil flows, shattered ridge effects, and compaction. Landslides and related ground failures were triggered as much as 12 km from the epicenter and accounted for about 200 fatalities and at least 100 damaged homes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Chieruzzi, R.1987GThe San Salvador earthquake of October 10, 1986 -- geotechnical effectsEarthquake SpectraVol. 33, pp. 483-489. Aug.El Salvador; earthquakes; 1986; Landslides; Liquefaction; Ground motion; soil conditions; San Salvador; El Salvador earthquake; Oct. 10; Earthquake DamageThe geotechnical effects generated by the earthquake--including observed ground failures such as landslides, lurching or cracking, and differential fill compaction and settlement--are described. The absence of liquefaction and surface faulting and the effects of floor compaction are discussed. A preliminary assessment is made which indicates that local geologic and soil conditions appear to have had some influence on the intensity of shaking and damage.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395VF?4 Lara, M. A.1987dThe San Salvador earthquake of October 10, 1986 -- history of construction practices in San SalvadorEarthquake SpectraVol. 33, pp. 491-496. Aug.zEl Salvador; earthquakes; 1986; Building codes; San Salvador; El Salvador earthquake; Oct. 10; Earthquake-Resistant DesignrConstruction practice in San Salvador, as in the rest of El Salvador, had remained practically unchanged since the time of Spanish colonization up to around 1942. From then on, building practices from many other countries have been introduced, and they have exerted a major influence. The last four decades (1940-1980) are divided into five stages or periods, each influenced by events, such as earthquakes in El Salvador and neighboring countries, the incorporation of foreign and discarding of local codes, and the introduction of new techniques such as soil mechanics and microseismic investigations. The contribution of practices based on foreign codes to the improvement of construction practice is assessed, for example, in the evaluation of seismic actions. Studies and records that can be used as a basis for the elaboration of an earthquake-resistant design code are noted.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395clHF?4&Shakal, A. F. Huang, M. J. Linares, R.1987OThe San Salvador earthquake of Octobe z499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395HF?4 Durkin, M. E.1987xThe San Salvador earthquake of October 10, 1986 -- casualties, search and rescue, and response of the health care systemEarthquake SpectraVol. 33, pp. 621-634. Aug.El Salvador; earthquakes; 1986; Nonstructural elements; Humans; Fires; Soils; Multistory structures; Hospitals; damage; Socioeconomic aspects; San Salvador; El Salvador earthquake; Oct. 10; Earthquakes as Natural DisastersThe earthquake caused a relatively large number of casualties. Approximately one-third of the fatalities occurred in engineered structures. The role of structural collapse, nonstructural elements, occupant actions, fire, and soil failure in earthquake injuries is discussed. The collapse of several multistory buildings necessitated heavy rescue operations by local authorities, foreign experts, and volunteers. Based on this experience, the need for better coordination of such efforts in future disasters is noted. Earthquake damage significantly disrupted local health services, causing evacuation of all major hospitals. Health care continues in temporary facilities. Future health service decentralization is discussed as a possible outcome.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Lara, M. A.1987xThe San Salvador earthquake of October 10, 1986 -- detailed evaluation of the performance of eight engineered structuresEarthquake SpectraVol. 33, pp. 543-562. Aug.El Salvador; earthquakes; 1986; Reinforced concrete structures; damage; Reinforced concrete shear walls; Multistory structures; Hotels; Reinforced concrete frames; San Salvador; El Salvador earthquake; Oct. 10; Earthquake Damage#Eight engineered buildings in San Salvador were selected to provide detailed descriptions of structures that performed both poorly and well during the 1986 earthquake. The buildings selected were all of reinforced concrete construction, both moment-frame and shear-wall, and were three to eight stories high. The earthquake performance of the eight buildings ranged from the moderately severe structural and nonstructural damage to the El Salvador Sheraton Hotel, which will require retrofitting, to the negligible nonstructural damage to the VIP Building at the Sheraton Hotel complex. Comparison of the performance of the various buildings indicates that newer buildings, especially those built since 1973, revealed less damage than older buildings designed and constructed under less stringent codes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395SF?4 Rymer, M. J.1987CThe San Salvador earthquake of October 10, 1986 -- geologic aspectsEarthquake SpectraVol. 33, pp. 435-463. Aug.El Salvador; earthquakes; 1986; faults; Volcanoes; Liquefaction; Tectonics; Landslides; San Salvador; El Salvador earthquake; Oct. 10; Earthquake DamageThe San Salvador earthquake struck an area of upper Cenozoic volcanic rocks consisting of basaltic to silicic flows and tuffs. Tuff deposits, which constitute the upper 30 m of section below San Salvador and thinner sections in the hills surrounding the city, are important in land pt, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4$Bongiovanni, G. Celebi, M. Safak, E.1987ASeismic rocking response of a triangular building founded on sandEarthquake SpectraVol. 34, pp. 793-809. Nov.TTriangular structures; Reinforced concrete structures; dynamic properties; response; Rocking; Free vibration tests; Fourier spectra; Ambient vibrations; Systems identification; Time history analysis; Mathematical models; soil-structure interaction; Modal analysis; Chile; aftershocks; Chile earthquakes; 1985; Vibration tests; Ground motionMA twenty-two story, triangular in plan, symmetrical reinforced concrete building on the beachfront in Vina del Mar, Chile, was temporarily instrumented in August 1985 following the Mar. 3, 1985, central Chile earthquake (M subscript s = 7.8) and aftershocks were recorded. Ambient and free vibration tests were also performed. The paper reports studies of the records of the responses of the building, the primary modes of vibration of the structure, its excellent performance during the earthquake, and results from analyses using mathematical models and system identification techniques.Earthquake Engineering Research Institute,  dence, other smaller normal fault traces, and compressional rolls are described. Evidence of level ground liquefaction and lateral spreading near rivers, eruption of sands at the ground surface, and well behavior are discussed. General regional subsidence of the alluvial plains in the area up to 2 m has been confirmed by leveling completed within three weeks of the earthquake. Extensive minor damage to roads and severe damage to many houses and other single-story structures, including factories and mills, is reported.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Bolt, B. A.19874One hundred years of earthquake recording in AmericaEarthquake SpectraVol. 34, pp. 641-644. Nov.^Seismograms; California; Univ. of; at Berkeley; Seismographic Stations; Engineering SeismologyFThe first permanent stations in the Western Hemisphere to record seismic ground motions were installed at Lick Observatory (Mt. Hamilton) and the Univ. of California (Berkeley) campus in 1887. The best available seismographs designed by Professor J. A. Ewing were installed at Lick Observatory and the Students Astronomical Observatory (Berkeley Campus). The first California earthquake recorded by the Lick instrument was on Apr. 24, 1887, and the first record at Berkeley was that of an explosion at a local powder works on Aug. 11, 1887. These seismographic stations have functioned continuously from their founding to the present day, recording over 150,000 earthquakes as well as underground nuclear explosions. Over 300,000 seismograms and 50 magnetic tapes kept on the Berkeley campus comprise a unique permanent reference library.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Olson, R. S. Olson, R. A.1987Urban heavy rescueEarthquake SpectraVol. 34, pp. 645-658. Nov.$Southern California; disaster planning; California; United States; Mexico City; earthquakes; 1985; Guerrero-Michoacan; Mexico earthquake; Sept. 19; disaster relief; Colombia; San Salvador; El Salvador earthquake; Oct. 10; 1986; Earthquake hazards; mitigation; Earthquakes as Natural DisastersQRecent foreign disasters reinforce the argument that it is past time to distinguish conceptually post-earthquake "urban heavy rescue" (UHR) from the generic "search and rescue." It is especially important to appreciate the problematic operational environment of UHR and the political as well as the lifesaving implications of UHR successes and failures. Effective UHR requires complex intergovernmental, public-private, and civil-military preparedness planning. At this time, UHR remains the weak link in the entire response chain to the inevitable major urban earthquake in the United States.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Thiel, C. C., Jr. Zsutty, T. C.19870Earthquake characteristics and damage statisticsEarthquake SpectraVol. 34, pp. 747-792. Nov.#Sites; structural damage; Alluvium; Masonry structures; damage prediction; Steel structures; Steel frames; Lowrise structures; Wooden structures; Wood; frames; Concrete; shear walls; Braced frames; Tall buildings; Masonry shear walls; Shear wall-frame interaction; Chimneys; Precast concreteA simple Markov distribution relates the probability of occurrence of five discrete damage states for a specific building type in an earthquake. The damage distribution depends on the building's structural system, the matching of the site and building periods, the site materials, and the site's acceleration. Constants in the model were determined using a maximum likelihood formulation and observations for a series of California and Chinese earthquakes. Model predictions are compared with damage data. A maximum likelihood method allows determination of ground motion, attenuation, and/or earthquake moment magnitude from observations of damage for structures located at diverse sites. A simple relationship exists for the average damage estimate that closely matches historical observations.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395'F?4MacLeod, J. D. Scott, S.19879Earthquake safety: California's comprehensive new programEarthquake SpectraVol. 34, pp. 811-819. Nov.California; legislation; Earthquake Hazards Reduction Act; Disaster planning; Disaster relief; Public information; Research; Masonry structures; Land use; Nonstructural elements; Earthquakes as Natural Disasters; Governmental AspectsIn 1985, California enacted the Earthquake Hazards Reduction Act, a landmark in seismic policy-making, that established a system of comprehensive and continuous planning, plan implementation, monitoring, and revision. The program set up by the act will further earthquake safety in six major areas: (1) existing development, (2) emergency preparedness and response, (3) new development, (4) long-term recovery, (5) education and public information, and (6) research and its application. The Seismic Safety Commission, an independent policy body that advises the Legislature and Governor, was chosen to lead the program. The first five-year program, which began in 1986, was revised in 1987 and a supplement for local government was added in January 1988.Earthquake Engineering Research Institute, 499 14th S Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Deppe, K.1988The Whittier Narrows, California earthquake of October 1, 1987 -- evaluation of strengthened and unstrengthened unreinforced masonry in Los Angeles CityEarthquake SpectraVol. 41, pp. 157-180. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; masonry structures; strengthening; damage; Los Angeles; building codes; structural strengthening; Southern California; earthquakes; Failure; Collapse; Masonry walls; Earthquake-Resistant Design]On Nov. 15, 1987, the City of Los Angeles' Earthquake Div. launched a study of the performance of its strengthened unreinforced masonry buildings during the Whittier Narrows earthquake. The objective of the study was twofold: (1) to analyze the damage to unstrengthened as well as to strengthened and tension-anchored-only buildings, and from that analysis (2) to determine the most effective ways of improving the design standards for strengthening unreinforced masonry buildings. The initial part of that objective has been completed, and the findings of that study are the primary basis for this paper.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Pender, M. J. Robertson, T. W.1987+Edgecumbe earthquake: reconnaissance reportEarthquake SpectraVol. 34, pp. 659-745. Nov.New Zealand; earthquakes; 1987; structural damage; Edgecumbe; New Zealand earthquake; Mar. 2; Chimneys; damage; Nonstructural elements; Pile foundations; Houses; Foundations; Bridges; Seismicity; Earthquake intensities; Accelerograms; New Zealand earthquakes; DamsNOn Mar. 2, 1987, an earthquake of magnitude (ML) 6.3 occurred close to the town of Edgecumbe in the North Island, New Zealand. The depth is provisionally estimated to be 8 plus or minus 1 km. Seismic activity in the general area during the previous week culminated in a foreshock on March 2 of ML 5.2. Four aftershocks with magnitudes in excess of 5.0 occurred on March 2. The earthquakes occurred at the end of summer after a long period of dry weather. Modified Mercalli intensities, peak ground accelerations, a complex series of surface scarps caused by the main shock, subsi yn effects. Comparisons between observed and simulated accelerograms for all the stations modeled are made using peak ground acceleration and using time histories and response spectra for the selected stations.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395XF?4Jones, L. M. Hauksson, E.1988LThe Whittier Narrows, California earthquake of October 1, 1987 -- seismologyEarthquake SpectraVol. 41, pp. 43-53. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; Southern California; earthquakes; faults; Los Angeles region; SeismologyThe earthquake was located at the northwestern end of the Puente Hills. The sequence ruptured a small part of a previously unidentified, buried thrust fault that strikes east-west and dips down to the north. This fault may be part of a large system of thrust faults extending across the entire east-west length of the northern margin of the Los Angeles Basin. The focus of the main shock is deep. The largest aftershock produced mostly strike-slip movement on a steeply dipping, northwest plane that bounds the main shock rupture area to the west. Enhancement of the Los Angeles Basin seismic network would facilitate investigation of the potential of these faults for moderate-sized or large earthquakes.  aining was also evident. Ethnicity was demonstrated as a factor that influences the public's response to earthquake hazard. Though the long-term impact of the earthquake on Southern California may be imperceptible, some segments of the population, such as low-income earthquake victims and marginal businesses, may experience difficulty recovering.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395; oclc4F?4)Wald, D. Somerville, P. G. Burdick, L. J.1988fThe Whittier Narrows, California earthquake of October 1, 1987 -- simulation of recorded accelerationsEarthquake SpectraVol. 41, pp. 139-156. Feb.Simulation; accelerograms; Green functions; Whittier Narrows; California earthquake; Oct. 1; 1987; simulated; Southern California; earthquakes; Engineering SeismologyAccelerograms from many of the strong-motion stations close to the main shock of the earthquake were simulated using a semi-empirical Green function summation technique. This method allows gross aspects of the source rupture process to be treated deterministically using a kinematic model based on first motion studies, teleseismic modeling, and the distribution of aftershocks. The simulations predict the observations accurately enough to identify which phases and amplitudes in the observed data may be due to local site response rather than source or radiatio usable and adequate for describing damage.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Chambers, M. D.1988tThe Whittier Narrows, California earthquake of October 1, 1987 -- asbestos hazards in post-earthquake investigationsEarthquake SpectraVol. 41, pp. 31-34. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; asbestos hazards; Asbestos; Southern California; earthquakes; Humans; Damage; Structures; Hazardous substances; Earthquakes as Natural DisastersyAsbestos-containing building materials (ACBM) can pose a significant hazard to design professionals and scientists engaged in post-earthquake building investigations. This paper discusses hazards of ACBM susceptible to damage by seismic activity. Investigators must be aware of the potential for exposure to asbestos and other hazardous materials and how to protect themselves.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395ǘF?4Tierney, K. J.1988PThe Whittier Narrows, California earthquake of October 1, 1987 -- social aspectsEarthquake SpectraVol. 41, pp. 11-23. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; socioeconomic aspects; Southern California; earthquakes; Disaster planning; California; southern; Los Angeles; Earthquakes as Natural DisastersThere were relatively few fatalities and casualties in the Whittier Narrows earthquake. However, social disruption was extensive, and there was an increased need for mental health services. Due to extensive mitigation and preparedness programs and to the moderate size of the event, the emergency response was, in general, well managed. Nevertheless, important insights were gained on potential weaknesses in areas such as communication coordination. Although the response by local residents was generally positive and adaptive, the need for improved public awareness and tr Vol. 41, pp. 115-137. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; ground motion; acceleration; California; southern; soil conditions; geologic conditions; Southern California; earthquakes; Embedded structures; Sites; Engineering SeismologyOne-hundred sixty-eight accelerograms from the earthquake were used to develop attenuation relationships for peak horizontal acceleration. The acceleration amplitudes were about 65 percent higher than predicted. This paper analyzes residuals that show a complex interaction of source mechanism, building embedment, site geology, and geography. Source effects that may have been responsible for the higher-than-expected accelerations as well as some of the observed azimuthal variation are also considered.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Brady, A. G.1988xThe Whittier Narrows, California earthquake of October 1, 1987 -- preliminary assessment of strong ground motion recordsEarthquake SpectraVol. 41, pp. 55-74. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; accelerograms; Southern California; earthquakes; California; southern; Tall buildings; Multistory structures; Hospitals; Los Angeles; Long Beach; Highways; Dynamic properties; Engineering SeismologyMore than 250 strong-motion accelerograph stations were triggered by the earthquake. This set of records, one of the more significant in history, was produced primarily by three networks, operated by the U.S. Geological Survey, the California Div. of Mines and Geology, and the Univ. of Southern California. The excellent performance of the instruments in these and the smaller arrays is attributable to the quality of the maintenance programs and their funding and personnel requirements. Prior to computer analysis of the analog film records, a number of important structural resonant modes can be identified, and frequencies and simple mode shapes have been scaled.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Moore, T. A. et al.,1988The Whittier Narrows, California earthquake of October 1, 1987 -- preliminary evaluation of the performance of strengthened unreinforced masonry buildingsEarthquake SpectraVol. 41, pp. 197-212. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; masonry structures; Southern California; building codes; earthquakes; Los Angeles; damage; strengthening; Warehouses; Multistory structures; Brick; Masonry; piers; Cracking; Earthquake Damage<This report presents preliminary case studies of the performance of selected unreinforced masonry buildings during the earthquake. Attention is focused on buildings located in the downtown Los Angeles area that have been rehabilitated to conform with the Los Angeles hazard reduction ordinance. No loss of life or major injuries were attributed to the response of unreinforced masonry buildings to the earthquakes; but in a significant number of both rehabilitated and nonstrengthened buildings, masonry peeling off upper story walls and falling bricks presented a hazard.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395+|F?4Leyendecker, E. V. et al.,1988xThe Whittier Narrows, California earthquake of October 1, 1987 -- early results of isoseismal studies and damage surveysEarthquake SpectraVol. 41, pp. 1-10. Feb.Isoseismal maps; California; southern; Whittier Narrows; California earthquake; Oct. 1; 1987; damage; Southern California; earthquakes; Earthquake intensities; Acceleration; structural damage; Ground motion; Earthquake magnitudes; Structures; damage prediction; Earthquake Damage\Preliminary isoseismals for modified Mercalli intensities are presented for the earthquake. Isoseismals for intensities VI and lower are based on responses to a mail survey. Intensity VII and larger are based on a field survey of damage described in this paper. Maximum observed intensity of VIII was confined to Whittier. Shapes of intensity contours were compared with distribution of average peak acceleration data from the strong-motion array in the greater Los Angeles area. The building classification and survey strategies developed were tested and found F?y4Rosenblueth, E.1988kThe Mexico earthquake of September 19, 1985 -- self-stimulated seismicity for noncharacteristic earthquakesEarthquake SpectraVol. 43, pp. 531-550. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; Seismicity; earthquake magnitudes; Mexico; earthquakes; Seismic risk; Building codes; Simulation; aftershocks; Design; Damage; earthquake simulation; Seismology; Earthquake RiskKA generalized linear version of Hawkes's self-exciting model serves to analyze and simulate foreshocks as well as background noise and aftershocks generated at a tectonic fault. The model's inputs are magnitudes and occurrence times of characteristic earthquakes. It is partly validated and calibrated for decision-making purposes using a physically based model and statistical data. The present model contains an excitation function relating earthquake magnitude to instantaneous increase in seismicity and a memory function describing the decrease in seismicity with time. The excitation function depends markedly on the zone, while the memory function has little sensitivity to this. Choice of memory function and its parameters rests on an optimum decision-making approach. Results are compared with data from different parts of the world.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?z4Garcia-Ranz, F. Gomez, R.1988oThe Mexico earthquake of September 19, 1985 -- seismic design regulations of the 1976 Mexico City building codeEarthquake SpectraVol. 43, pp. 427-439. Aug.Mexico City; building codes; earthquakes; 1985; Mexico; Ductility; Design spectra; Static analysis; Pounding; Tanks; Retaining walls; Guerrero-Michoacan; Mexico earthquake; Sept. 19; Earthquake-Resistant DesignmThis paper is an English translation of the seismic design regulations of the 1976 Mexico City building code.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395@F?{4Campillo, M. et al.,1988The Mexico earthquake of September 19, 1985 -- the incident wavefield in Mexico City during the great Michoacan earthquake and its interaction with the deep basinEarthquake SpectraVol. 43, pp. 591-608. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; wave propagation; Mexico; Mexico City; soils; earthquakes; response; Soil conditions; ground motion; Engineering SeismologyVertical displacement records were used to identify the nature of the waves responsible for the heavy damage suffered in Mexico City.F?|4!Gates, J. H. Mellon, S. Klein, G.1988aThe Whittier Narrows, California earthquake of October 1, 1987 -- damage to State highway bridgesEarthquake SpectraVol. 42, pp. 377-388. MayWhittier Narrows; California earthquake; Oct. 1; 1987; highway bridges; Reinforced concrete; Southern California; earthquakes; Precast concrete; bridges; Box girder bridges; damage; Earthquake DamageDamage to State highway bridges was confined primarily to one bridge at the Interstate 605 and 5 interchange. Shear damage, classified as moderate, occurred to the columns of one bent. The bridge was shored up and opened to traffic in less than 22 hours. Minor damage also occurred at bearings and other locations on sixteen other bridges. Evidence of movement was also noted on seven other bridges.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395_ F?}4Priestley, M. J. N.1988cThe Whittier Narrows, California earthquake of October 1, 1987 -- damage to the I-5/I-605 separatorEarthquake SpectraVol. 42, pp. 389-405. MayWhittier Narrows; California earthquake; Oct. 1; 1987; highway bridges; Southern California; earthquakes; Reinforced concrete; Shear strength; columns; Joints; damage; Earthquake Damage6The separator, a major nine-span bridge, was severely damaged in the earthquakes. All columns of Bent 6, which is supported on the median strip of the Santa Ana Freeway (I-5), suffered shear failures; and the supported spans came close to collapse. Other minor damage included minor column hinging at more flexible bents, abutment pounding, and fracture of keeper plates at abutment rockers. Preliminary calculations indicate that the shear failures of Bent 6 resulted from disproportionate flexural and shear strengths of the columns, attributable to the working stress philosophy adopted in design, and the much greater stiffness of Bent 6 than adjacent bents. Movement joints with cable restrainers, at both ends of spans founded on Bent 6, make estimation of lateral load transfer from more flexible regions difficult.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?~4Taly, N.1988The Whittier Narrows, California earthquake of October 1, 1987 -- performance of buildings at California State University, Los AngelesEarthquake SpectraVol. 42, pp. 277-317. MaybWhittier Narrows; California earthquake; Oct. 1; 1987; educational institutions; Southern California; earthquakes; California State Univ. at Los Angeles; Los Angeles; Asbestos; Reinforced concrete shear walls; damage; Multistory structures; Soft stories; Reinforced concrete beams; Reinforced concrete columns; Parking structures; Libraries; Book shelvesThe earthquake caused some 20.5 million dollars damage to various engineered buildings at California State Univ., Los Angeles, and the death of a student due to a falling precast concrete panel. Peak ground acceleration of 0.39 g and a building response of 0.48 g were recorded in one of the affected buildings. This paper examines both structural and nonstructural damage: fire, toxic chemical spills, and contamination from existing asbestos.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4)Hamburger, R. O. McCormick, D. L. Hom, S.1988bThe Whittier Narrows, California earthquake of October 1, 1987 -- performance of tilt-up buildingsEarthquake SpectraVol. 42, pp. 219-254. MayWhittier Narrows; California earthquake; Oct. 1; 1987; tilt-up structures; damage; building codes; Southern California; earthquakes; Nonstructural elements; Reinforcement; Walls; Roofs; Industrial plants; Concrete structures; Masonry structures; Box structures; Anchor bolts; JointsThis paper discusses the response of tilt-up buildings during the earthquake. Approximately 120 tilt-ups were surveyed after the Whittier event. The effectiveness of code changes adopted after 1971 to mitigate wall anchorage and diaphragm continuity problems is discussed.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E239571lF?4Hart, G. C. Ewing, R. D.1988eThe Whittier Narrows, California earthquake of October 1, 1987 -- response of a tall masonry buildingEarthquake SpectraVol. 42, pp. 319-337. MayWhittier Narrows; California earthquake; Oct. 1; 1987; hotels; masonry structures; Southern California; earthquakes; damage; nonlinear response; building codes; design; Multistory structures; Masonry shear walls; Reinforcement; Time history analysis; Hysteresis; Cracking; OverturningThe Hilton Hotel in Whittier, California, is an eight-story, reinforced hollow unit concrete masonry building. It experienced a peak ground acceleration of approximately 60 percent gravity without visible structural damage. This paper analyzes the building from two perspectives. The first is a structural engineering design perspec $ast decisions, present danger: an historical perspective on ecology and earthquakes in Mexico CityEarthquake SpectraVol. 43, pp. 469-479. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; Mexico City; land use; earthquakes; Mexico; Earthquakes as Natural Disasters; Governmental Aspects6Why is one of the world's most populous cities built on land with a history of subsidence, seismicity, and flooding? Mexico City illustrates how early decisions in a city's history can create difficult conditions for building well and living safely. The Aztecs had little choice but to live on the muddy islands in Lake Texcoco, the present site of downtown Mexico City; but the Spanish did have a choice. By selecting the island capital of Tenochtitlan for their colonial capital, they bequeathed to succeeding generations problems that were apparent to them almost as soon as they began construction. Their solution to the hydraulic problems of the site exacerbated the ecological and seismic problems that the present-day inhabitants must face and destroyed the reason the first settlers inhabited the Valley of Mexico.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 orced masonry buildings during the Oct. 1, and 3, 1987, Whittier Narrows earthquakes was documented in a comprehensive building survey. This paper describes the extent of the survey, the type of data collected, and a preliminary summary of some survey results.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395MF?4Trifunac, M. D.1988The Whittier Narrows, California earthquake of October 1, 1987 -- note on peak accelerations during the 1 and 4 October earthquakesEarthquake SpectraVol. 41, pp. 101-113. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; acceleration; ground motion; California; southern; Southern California; earthquakes; Attenuation; Source mechanisms; Engineering SeismologyAttenuation patterns of the recorded peak accelerations during two moderate earthquakes in Los Angeles are described. This paper discusses the significant profile of the physical processes shaping ground motion recorded by dense arrays of accelerographs.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395]F?4Campbell, K. W.1988vThe Whittier Narrows, California earthquake of October 1, 1987 -- preliminary analysis of peak horizontal accelerationEarthquake Spectra :eb.Whittier Narrows; California earthquake; Oct. 1; 1987; disaster relief; Southern California; earthquakes; Los Angeles; Earthquakes as Natural DisastersThe earthquake was the most significant seismic event to occur in Southern California since the San Fernando earthquake of February 1971. As such, the 5.9 magnitude temblor provided a basis for evaluating the level of preparedness in at least a portion of the Los Angeles metropolitan region. The Whittier Narrows event provides a hint of the progress that has been made in local, state, and private sector preparedness in the last six years as well as suggesting areas that need additional effort.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 (F?4&Hart, G. C. Kariotis, J. Noland, J. L.1988eThe Whittier Narrows, California earthquake of October 1, 1987 -- masonry building performance surveyEarthquake SpectraVol. 41, pp. 181-196. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; masonry structures; damage; Reinforced masonry structures; Pasadena; California; Southern California; earthquakes; Earthquake Damage>The observed earthquake response of unreinforced and reinf ,ridges; Airport towers; Towers; Electric power plants; California Strong-Motion Instrumentation Program; Engineering SeismologyThe earthquake generated the largest set of strong-motion records ever obtained from a single earthquake. The California Strong Motion Instrumentation Program (CSMIP) recovered 128 strong-motion records from 101 stations. Of these 101 stations, 63 are ground-response stations and 38 are extensively instrumented structures. The structures include 27 buildings, eight dams, a suspension bridge, an airport tower, and a power plant. This paper summarizes that data set and highlights records of particular interest.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Andrews, R.1988TThe Whittier Narrows, California earthquake of October 1, 1987 -- emergency responseEarthquake SpectraVol. 41, pp. 25-30. F structural damage prediction; Residential buildings; Cost analysis; Southern California; earthquakes; Earthquake DamagepThis paper examines current methods of risk assessment in the context of the Whittier Narrows earthquake. An assessment requires determining the incidence of damage to the elements at risk in order to establish vulnerability. It is necessary to produce estimates of the elements at risk and apply the best information available concerning damage. This requires considering the total physical context in which the disaster occurred, by estimating population, number of buildings, building floor area, and building replacement cost for the modified Mercalli intensity VI, VII and VIII areas and by calculating incidence rates.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23954F?4%Shakal, A. F. Huang, M. J. Cao, T. Q.1988ZThe Whittier Narrows, California earthquake of October 1, 1987 -- CSMIP strong motion dataEarthquake SpectraVol. 41, pp. 75-100. Feb.@Whittier Narrows; California earthquake; Oct. 1; 1987; accelerograms; Southern California; earthquakes; California; southern; Response spectra; Concrete structures; response; Dams; Suspension b L 1, 1987 -- Ticor Title Insurance Building damageEarthquake SpectraVol. 42, pp. 255-276. MayWhittier Narrows; California earthquake; Oct. 1; 1987; office buildings; Southern California; earthquakes; damage; Warehouses; Tilt-up structures; Concrete; walls; Roofs; Bracing; Joints; Anchors (structural); Structural configuration; Shear walls; Floors:The Ticor Title Insurance Building is a recently designed building that was significantly damaged by the earthquake. The building experienced shear wall failures and floor and roof diaphragm failures, as well as failures of spandrel panel anchorages. The damage is chronicled by photographs in this paper. This building, which is constructed chiefly of precast elements, shows the importance of adequately tying together different parts of a building. Special attention to building configuration, building deflection, and connection and anchorage details is recommended.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395(F?4Jones, B. G. Nicolaides, C. N.1988SThe Whittier Narrows, California earthquake of October 1, 1987 -- buildings at riskEarthquake SpectraVol. 41, pp. 35-42. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; seismic risk; damage prediction; ., [URL:http://www.eeri.org] %Lcallno 400/E2395F?4 Schiff, A. J.1988WThe Whittier Narrows, California earthquake of October 1, 1987 -- response of elevatorsEarthquake SpectraVol. 42, pp. 367-375. MayWhittier Narrows; California earthquake; Oct. 1; 1987; elevators; Southern California; building codes; earthquakes; damage; Earthquake DamageThe earthquake was the first to affect a significant number of the elevators that conform to the more stringent code provisions introduced after the 1971 San Fernando earthquake. This paper discusses the most important components of an elevator system's response: machine room and rope damage, incidence of counterweights coming out of their guide rails, and the performance and operation of elevator earthquake protection devices such as seismic switches and counterweight derail detection devices. Code changes are recommended.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395W!hF?4 Estes, K.1988gThe Whittier Narrows, California earthquake of October \d, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395}O&F?4 Schiff, A. J.1988~The Whittier Narrows, California earthquake of October 1, 1987 -- response of lifelines and their effect on emergency responseEarthquake SpectraVol. 42, pp. 339-366. May1Whittier Narrows; California earthquake; Oct. 1; 1987; lifeline systems; Southern California; earthquakes; Telecommunications systems; damage; Gas supply systems; Electric power distribution; Tanks; Airports; Water supply systems; Pipelines; Disaster planning; California; southern; Transportation systemsThe response of lifeline systems was good, but there were component failures. Communication inadequacies did have a significant impact on the emergency response system. The dysfunction of lifelines, primarily power, communication, and natural gas systems, put an added burden on the emergency response system and was the source of most fires. Damage and dysfunction included failure of ceramic elements on high-voltage substation equipment, damage to large liquid storage tanks, and the saturation of the telephone system, including emergency response networks, with inappropriate calls. The need to change operating procedures of some lifelines and to update emergency response public information is indicated.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org] +tive using the structural mechanics assumptions consistent with the new strength design criteria for hollow unit shear walls in the 1988 Uniform Building Code and a response spectrum analysis. The second perspective is based on a nonlinear lumped-parameter time history model and a step-by-step time history analysis.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oaklan  of California at San Diego. It consists of 30 strong-motion accelerographs on solid rock sites in Guerrero and the neighboring states of Mexico. The first instruments were in place in March 1985 and about two-thirds of the instruments were installed by the end of November 1985. The network produced significant data from the Sept. 19, 1985, Mexico earthquake and its major aftershock of September 21. During 1985 and 1986, the network recorded 158 accelerograms from 85 earthquakes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?s4Garcia-Ranz, F. Gomez, R.1988wThe Mexico earthquake of September 19, 1985 -- live load specifications of the 1976 and 1987 Mexico City building codesEarthquake SpectraVol. 43, pp. 461-467. Aug.Mexico City; building codes; earthquakes; 1985; Mexico; Guerrero-Michoacan; Mexico earthquake; Sept. 19; Loads; live; Earthquake-Resistant DesignsThis paper is an English translation of the live load requirements of the 1976 and 1987 Mexico City building codes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395,F?t4Hong, H. P. Rosenblueth, E.1988]The Mexico earthquake of September 19, 1985 -- model for generation of subduction earthquakesEarthquake SpectraVol. 43, pp. 481-498. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; models; Mathematical models; earthquakes; Simulation; Mexico; Seismology:A mathematical model based on both statistical data and the salient features of the event's physical phenomena is presented. The model simulates the magnitudes and occurrence times of subduction earthquakes and may also apply to other tectonic seisms. Linear springs and dashpots are used to idealize the magmatic drag and push on tectonic plates and the latter's behavior. The rupture area is divided into many faultlets whose frictional strength is lognormally distributed; this strength drops upon breakage and is then gradually recovered. Without introducing ad-hoc features to fit the seismic data, the model produces essentially correct magnitude exceedance rates, quasi-periodic characteristic earthquakes, sequences of foreshocks and aftershocks, and background noise. It can be extended to include spatial correction.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?u4(Grigoriu, M. Ruiz, S. E. Rosenblueth, E.1988cThe Mexico earthquake of September 19, 1985 -- non-stationary models of seismic ground accelerationEarthquake SpectraVol. 43, pp. 551-568. Aug."Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; acceleration; Simulation; accelerograms; Single degree-of-freedom systems; linear response; nonlinear response; Nonlinear systems; Linear systems; Ductility; models; Mexico City; earthquakes; Mexico; Reliability; Engineering SeismologyAn accelerogram recorded in the soft soil of Mexico City during the 1985 earthquake serves to calibrate nonstationary acceleration models. Responses of linear and nonlinear single degree-of-freedom systems indicate that the process with modulated amplitude and frequency is preferable for reliability studies. Coefficients of variation of ductility demands of systems excited with accelerograms generated by the model with moderate amplitude and frequency are close to those corresponding to actual accelerograms.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395XF?v4Sanchez-Sesma, F. J. et al.,1988^The Mexico earthquake of September 19, 1985 -- on the seismic response of the Valley of MexicoEarthquake SpectraVol. 43, pp. 569-589. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; Ground motion; soil conditions; Geologic conditions; Wave propagation; structural damage; Damage; Seismic zoning; Simulation; accelerograms; Clays; Brick; Adobe; Mexico; earthquakes; Site surveysTo explain damage and observed ground motions in Mexico City during the 1985 Michoacan earthquake, simultaneous consideration must be given to source, path, and site conditions. This is clear from teleseismic records and local vertical displacements. Incident waves played an important part in the frequency band of 0.3-1 Hz. Damage distribution and observed motion in the lakebed zone are not explicable through one-dimensional theory. The effects of lateral irregularities are required. The stratigraphic setting of the valley is described and some features of damage distribution with results for one- and two-dimensional wave propagation models are discussed to help establish on a quantitative basis the importance of lateral heterogeneity.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?w4Jara, J. M. Rosenblueth, E.1988~The Mexico earthquake of September 19, 1985 -- probability distribution of times between characteristic subduction earthquakesEarthquake SpectraVol. 43, pp. 499-529. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; seismic risk; Mexico; return periods; earthquakes; Seismology; Earthquake RiskBased on simulation using a physically based mathematical model and on data from various parts of the world, the authors postulate a slip-predictable model and four candidate distributions with random parameters for the distribution of interoccurrence times in subduction zones: lognormal, gamma, inverse Gaussian, and Weibull. Probabilities are updated using data from three groups of subduction earthquakes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395h;F?x4 Tobriner, S.1988The Mexico earthquake o 7 propagation models of the seismic accelerations incorporate the wave propagation profiles at three of those sites. The undamped computer surface acceleration spectra compare well with the recorded ones for two sites. The other does not produce adequate results, perhaps because of lack of information on shear wave velocities. Investigation using a site impulse function indicates that surface accelerations during the September 19 event had a frequency content determined, to a certain extent, by the natural periods of the site. The relationship between spectral periods corresponds to the closed-form solution of a homogeneous layer with a fixed base.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?n4Ordaz, M. et al.,1988zThe Mexico earthquake of September 19, 1985 -- estimation of response spectra in the lake bed zone of the Valley of MexicoEarthquake SpectraVol. 44, pp. 815-834. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; response spectra; Mexico; earthquakes; structural design; Fourier spectra; Ground motion; soil conditions; Random vibration analysis; Design; Engineering Seismology; Spectral ratios; Valley of Mexico; Clays; nonlinear response The authors estimate pseudo-acceleration response spectra with 5 percent damping (Sa) at 22 lake bed sites in the Valley of Mexico. The method used consists of (1) estimation of Fourier acceleration amplitude spectra (FAS) at the sites via observed FAS at Ciudad Univ. (CU) and compiled spectral ratios of these sites with respect to CU obtained from recorded earthquakes; (2) estimation of the duration of strong ground motion during the 1985 earthquake at these sites; and (3) application of random vibration theory to predict Sa. A constant duration of 71 sec at all sites is found to be satisfactory. Although the authors' results generally agree with reported effects, some uncertainties argue against direct use of the computed response spectra for code or design purposes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395eF?o4Bard, P. Y. et al.,1988The Mexico earthquake of September 19, 1985 -- a theoretical investigation of large- and small-scale amplification effects in the Mexico City ValleyEarthquake SpectraVol. 43, pp. 609-633. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; amplification; Mexico; Soil conditions; ground motion; Geologic conditions; Clays; Mexico City; seismic microzoning; earthquakes; Earthquake DamageThe linear large- and small-scale amplification effects in the Mexico City Valley, relating to both the superficial clay layer and the underlying thick sediments, are investigated with two-dimensional models and compared with one-dimensional models.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23954F?p4Gomez, R. Garcia-Ranz, F.1988zThe Mexico earthquake of September 19, 1985 -- complementary technical norms for earthquake resistant design--1987 editionEarthquake SpectraVol. 43, pp. 441-459. Aug.'Mexico City; building codes; seismic zoning; earthquakes; 1985; Mexico; Guerrero-Michoacan; Mexico earthquake; Sept. 19; Static analysis; Design spectra; Story shear; Overturning; Soil-structure interaction; Torsion; Response spectrum analysis; Time history analysis; Earthquake-Resistant DesignThis paper is an English translation of the technical norms for seismic design contained in the 1987 Mexico City building code.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?q4 Esteva, L.1988iThe Mexico earthquake of September 19, 1985 -- consequences, lessons, and impact on research and practiceEarthquake SpectraVol. 43, pp. 413-426. Aug.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; Columns; damage; Nonlinear response; Pounding; Soil-structure interaction; P-delta effects; Waffle slabs; Foundations; Soils; Mexico; building codes; earthquakes; Mexico City; ground motion; soil conditionsVThis paper serves as an introduction to the special issue dedicated to results of the research on this earthquake: the damage it caused and the preventive measures needed in the future. In the latter case, the focus is on structural engineering issues: brittle failure of columns, uncertainty associated with nonlinear response, pounding and soil-structure interaction, overloading of buildings, P-delta effects, unsatisfactory performance of waffle slabs, previous damage, foundation failure, and local soil strains. Changes in the building code for use in the reconstruction period are discussed.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 LF?r4Anderson, J. G. Quaas, R.1988The Mexico earthquake of September 19, 1985 -- effect of magnitude on the character of strong ground motion: an example from the Guerrero, Mexico strong motion networkEarthquake SpectraVol. 43, pp. 635-646. Aug.Accelerograms; Mexico earthquakes; 1985; Guerrero-Michoacan; Mexico earthquake; Sept. 19; ground motion; earthquake magnitudes; Response spectra; Engineering SeismologyThe Guerrero strong-motion network is a digital strong-motion network operated as a joint project of the Inst. of Engineering, Univ. Nacional Autonoma de Mexico and the Inst. of Geophysics and Planetary Physi tion of neighboring zones of firm soil or rock that amplify the ground motion in the soft soil between them as much as 100 percent, causing the high intensities observed in some districts of the city. Based on these results, new seismic zoning was proposed for the 1987 Mexico City Building Code.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?a4Aguilar, J. et al.,1989The Mexico earthquake of September 19, 1985 -- statistics of damage and retrofitting techniques in reinforced concrete buildings affected by the 1985 earthquakeEarthquake SpectraVol. 51, pp. 145-151. Feb. Mexico; earthquakes; 1985; Guerrero-Michoacan; Mexico earthquake; Sept. 19; strengthening; reinforced concrete structures; damage; Waffle slabs; Steel frames; Concrete; frames; Masonry walls; Composite structures; Repairs; Foundations; Shear walls; Pile foundationsVThe earthquake caused very serious damage, especially in reinforced concrete buildings, making it necessary to repair and strengthen many structures. The authors had the opportunity to study 114 of these retrofitted buildings. The database of collected information contains the description of each building, damage, and retrofitting techniques used. The statistical analysis of this information makes it possible to identify the correlation among the structural and foundation types, the dominant failure modes, the causes of damage, and the retrofitting techniques used in this group of buildings.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395|F?b4Ruiz, S. E. Diederich, R.1989jThe Mexico earthquake of September 19, 1985 -- the seismic performance of buildings with weak first storeyEarthquake SpectraVol. 51, pp. 89-102. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; Damage; Mexico; earthquakes; Displacements (structural); Ductility; Structural members; nonlinear response; Frames; Time histories; Soft stories; Strength; Multistory structures; Energy absorption; nonlinear structures; Mexico CityEight percent of the buildings damaged during the earthquake had a weak first story. Though the damage may have resulted from a combination of several features, this paper studies the possible influence of lateral strength discontinuity in the ductility demand at the first story, and tries to formulate the behavioral response by considering the east-west component of the highest acceleration record obtained on soft soil. A parametric study for five- and twelve-story buildings with a weak first story is presented. The upper story infill walls were brittle in some cases and ductile in others. It is shown that the absorption capacity of ductile walls plays an important role in the displacement ductility demands of the first story.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?c4Jara, M. et al.,1989nThe Mexico earthquake of September 19, 1985 -- typical cases of repair and strengthening of concrete buildingsEarthquake SpectraVol. 51, pp. 175-193. Feb.+Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; strengthening; reinforced concrete structures; concrete structures; Mexico; earthquakes; Steel; bracing; Reinforced brick; walls; Office buildings; Infill walls; Masonry walls; Reinforced masonry; Reinforced concrete frames; Apartment buildingsThis paper describes the most important techniques that are being used in Mexico City to retrofit buildings damaged during the 1985 earthquake. The information is presented by means of four case studies. These cases offer practical design examples of the typical solutions adopted and illustrate the various aspects of the repair and strengthening process such as damage assessment, emergency measures for temporary protection, the retrofitting technique employed in each case, and considerations and decisions made in the analysis and design.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?d4%Norena, F. Castaneda, C. Iglesias, J.1989mThe Mexico earthquake of September 19, 1985 -- evaluation of the seismic capacity of buildings in Mexico CityEarthquake SpectraVol. 51, pp. 19-24. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; damage prediction; Mexico; earthquakes; Structural configuration; structural damage; Multistory structures; Mexico City; structural damage prediction; Earthquake DamageRAs a consequence of the earthquake, city authorities decided to evaluate the seismic capacity of the undamaged buildings, to detect those with the most vulnerability, for future preventive action. Based on the census of the structures in the city, the evaluating procedure followed three levels of increasing precision, with good results.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395YF?e4Singh, S. K. et al.,1988The Mexico earthquake of September 19, 1985 -- a study of amplification of seismic waves in the Valley of Mexico with respect to a hill zone siteEarthquake SpectraVol. 44, pp. 653-673. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; amplification; ground motion; Mexico; earthquakes; geologic conditions; Sites; Fourier spectra; Spectral ratios; Valley of Mexico; Clays; nonlinear response; Response spectra; Earthquake DamageSince the installation of an extensive digital strong-motion array by Fundacion Javier Barros Sierra in 1987, three moderate earthquakes have been recorded by the array and by the accelerographs of the Inst. de Ingenieria, Univ. Nacional Autonoma de Mexico. Using this new data and results from the analysis of previous accelerograms, spectral ratios at 40 sites in the Valley of Mexico are presented with respect to a hill zone site at Ciudad Univ.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395S F?f4Mendoza, M. J. Auvinet, G.1988^The Mexico earthquake of September 19, 1985 -- behavior of building foundations in Mexico CityEarthquake SpectraVol. 44, pp. 835-853. Nov.,Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; foundations; Mexico; earthquakes; Pile foundations; soil-structure interaction; Composite structures; Footings; School buildings; Reinforced concrete structures; Apartment buildings; Mat foundations; Overturning; Soils; Settlement; Ground motionDuring the 1985 earthquake, a number of Mexico City building foundations on lacustrine soft soil performed inadequately. Previous high static content stresses between foundation and supporting subsoil propitiated the appearance of plastic deformations of the soil under seismic cyclic stresses, which led to settlement and tilting of the buildings. Construction on friction piles sustained the most severe damage. The main factor was the pronounced dynamic magnification of seismic movements associated with the quasi-coincidence between natural period of some structures and the long period of subsoil motions, which led to large overturning moments and shear forces at the foundation level.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?g4Jaime, A. Romo, M. P.1988uThe Mexico earthquake of September 19, 1985 -- correlations between dynamic and static properties of Mexico City clayEarthquake SpectraVol. 44, pp. 787-804. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; clays; Mexico; earthquakes; Mexico City; Static tests; Stress-strain relations; Velocity; Shear moduli; Field investigations; dynamic properties; Soils; Soil; Foundation Dynamics7This paper discusses several empirical correlations between dynamic shear modulus and void ratio and static shear modulus and between shear wave velocity and electric cone point resistance. In addition, the results of field and laboratory measurements of the dynamic properties of Mexico City clay are compared.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?h4-Ovando-Shelley, E. Mendoza, M. J. Romo, M. P.1988nThe Mexico earthquake of September 19, 1985 -- deformability of Mexico City hard deposits under cyclic loadingEarthquake SpectraVol. 44, pp. 753-770. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; soils; Mexico; earthquakes; pile foundations; soil-structure interaction; Stress-strain relations; Triaxial tests; Cyclic loads; Axial loads; nonlinear response; Settlement; Static loads; Viscous damping; Pore pressures; Hysteresis^Buildings founded on point-bearing piles performed better than those founded on friction piles during this earthquake. Nevertheless, a few buildings supported on end-bearing piles tilted considerably afterwards. Friction piles have been preferred in Mexico City because end-bearing piles have drawbacks resulting from the apparent immersion of structures due to regional subsidence. It has been shown that stress path testing can be used to obtain a deformability parameter to calculate permanent deformations induced by earthquake loading below end-bearing piles. The use of this parameter is illustrated.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?i4"Romo, M. P. Jaime, A. Resendiz, D.1988rThe Mexico earthquake of September 19, 1985 -- general soil conditions and clay properties in the Valley of MexicoEarthquake SpectraVol. 44, pp. 731-752. Nov. Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; soils; clays; Mexico; earthquakes; dynamic properties; response; Damping; Cyclic loads; Triaxial tests; Stress-strain relations; Wave propagation; Mexico City; Field investigations; Saturated soils; Shear moduli{The results of resonant column and cyclic triaxial tests on clay samples obtained from different sites in the lake zone of the Valley of Mexico are discussed. Of particular interest are the nearly elastic behavior and low damping ratio even for shear strain amplitudes as high as 0.3 percent. A hyperbolic model reproduces the resulting shear modulus versus strain curves. Degradation of shear modulus caused by load repetition is negligible for strains lower than 1 percent, but increases significantly for higher strains. Analyses of ground motions show one-dimensional wave propagations useful to predict free-field seismic motions.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?j4 Castro, R. Singh, S. K. Mena, E.1988The Mexico earthquake of September 19, 1985 -- an empirical model to predict Fourier amplitude spectra of horizontal ground motionEarthquake SpectraVol. 44, pp. 675-685. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; Fourier spectra; ground motion; Mexico; Sites; earthquakes; spectra; Engineering Seismology; Spectral ratiosFFourier acceleration amplitude spectra are analyzed for 14 coastal earthquakes recorded at a hill zone site at Ciudad Univ. (CU), Mexico City, 282 to 466 km from the rupture area. The observed smoother spectra are approximated in terms of the magnitude and distance for 18 periods. The observed spectra at CU are not reliable for most earthquakes beyond this period range. The predicted Fourier spectra for the 1985 earthquake (Ms = 8.1) are less than the observed Fourier spectra for T greater than or equal to 0.6 sec, suggesting an anomalously large radiation toward Mexico City at these periods, in agreement with the teleseismic evidence. Fourier spectra at several Mexico City sites (many on the lake bed zone) can be obtained from the predicted Fourier spectra at CU and the known spectral ratios of these sites with respect to CU.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?k4$Lermo, J. Rodriguez, M. Singh, S. K.1988The Mexico earthquake of September 19, 1985 -- natural period of sites in the Valley of Mexico from microtremor measurements and strong motion dataEarthquake SpectraVol. 44, pp. 805-814. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; site response; Mexico; earthquakes; Valley of Mexico; Fourier spectra; Design spectra; Microearthquakes; Soil conditions; ground motion; Engineering SeismologyTThe period at which the peak in the microtremor Fourier velocity spectra occurs in the transition and lake bed zones of the Valley of Mexico is found to be the natural period of the site. These periods in the valley are compiled from the microtremor measurements carried out by the Inst. de Ingenieria, Univ. Nacional Autonoma de Mexico and scientists from Japan (for 181 sites). Using this data and the natural periods estimated from strong-motion recordings (36 sites), an isoperiod contour map of the valley is presented. This map may be useful in the future in designing important structures.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?l4Seed, H. B. et al.,1988rThe Mexico earthquake of September 19, 1985 -- relationships between soil conditions and earthquake ground motionsEarthquake SpectraVol. 44, pp. 687-729. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; ground motion; soil conditions; Mexico; earthquakes; Clays; Mexico City; Response spectra; Rocks; Acceleration; Earthquake DamageThe characteristics of ground motions are compared for five sites underlain by clay at which ground motions were recorded in Mexico City during the earthquake and for which analyses of ground response have been made, based on the measured properties of soils and the motions recorded on hard formations at the Univ. Nacional Autonoma de Mexico (UNAM). It is shown that the ground response in areas of Mexico City underlain by clay is extremely sensitive to small changes in shear wave velocity of the clay, and it is suggested that a probabilistic approach allowing for uncertainties in shear wave velocity and in the characteristics of motions on the hard formations would be desirable.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395zCKF?m4 Rukos, E. A.1988_The Mexico earthquake of September 19, 1985 -- earthquake behavior of soft sites in Mexico CityEarthquake SpectraVol. 44, pp. 771-786. Nov.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; soils; soil conditions; Spectra; Mexico; earthquakes; Mexico City; Wave propagation; Acceleration; Ground motion; Sites; Response spectra; Accelerograms; Mexico earthquakes; Earthquake DamageThere are several acceleration records from the Sept. 19, 1985, Mexico earthquake for the soft (lake bed) sites in Mexico City. One-dimensional  f the dynamic analysis show that to obtain the same safety level, the maximum ordinate of the design spectrum should be larger than the static base shear coefficient, leading to a 0.8 maximum ordinate. When the resistant shear force is plotted as a function of the natural period of each building, the response spectrum is very similar to the inelastic spectrum derived from the accelerograms. New design spectra are proposed for the high seismicity areas of Mexico City.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?_4)Ruiz, S. E. Rosenblueth, E. Diederich, R.1989eThe Mexico earthquake of September 19, 1985 -- seismic response of asymmetrically yielding structuresEarthquake SpectraVol. 51, pp. 103-111. Feb.IGuerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; asymmetric structures; nonlinear structures; Mexico; building codes; earthquakes; nonlinear response; Structural configuration; structural response; Hysteresis; bilinear systems; Linear systems; Ground motion; Response spectra; Ductility; Single degree-of-freedom structuresSome structures yield asymmetrically in two opposite directions due to structural configuration, asymmetry in loads, or tilting. As a consequence, the capacity to resist earthquake motion can be great, owing to a tendency to accumulate inelastic deformations in the weaker sense. This phenomenon is studied for a single degree-of-freedom hysteretic bilinear system subjected to simulated accelerograms of the east-west component of the motion registered during the 1985 earthquake. The evolutionary power concept and approximate practical rules, which were incorporated into the new Mexican seismic code, are deduced. The influence of motion duration on this type of structure is pointed out.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395SbF?`4 Iglesias, J.1989fThe Mexico earthquake of September 19, 1985 -- seismic zoning of Mexico City after the 1985 earthquakeEarthquake SpectraVol. 51, pp. 257-271. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; seismic zoning; Mexico; building codes; earthquakes; Concrete structures; Multistory structures; Base shear; Earthquake intensities; Ground motion; geologic conditions; Soil conditions; Brick; walls; Failure; concrete wallsUsing a simplified method for the evaluation of the seismic capacity of medium-rise concrete structures, the base shear coefficient was obtained for failure (resistance coefficient) for 162 buildings and used as an evaluation index. For the 90 evaluated structures that suffered severe damage, the resistance coefficients were used to elaborate a map of intensities for the 1985 earthquake. This map shows the strong interac / September 19, 1985 -- new accelerograph network for Mexico CityEarthquake SpectraVol. 51, pp. 249-255. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; strong-motion instrument arrays; Mexico; earthquakes; Accelerographs; Accelerograms; Mexico earthquakes; Fourier spectra; Mexico City; Strong Motion Seismometry6As a result of the observed effect of the earthquake, the local government authorities increased their support for the installation of a city-wide accelerograph network. This paper presents the activities developed by the Centro de Instrumentacion y Registro Sismico (CIRES) concerned with the selection and procurement of suitable instruments, identification of the installation sites, and installation of the field stations. The methods applied to the processing of seismic records are described and a catalog summary of accelerograms recorded to date is included.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?]4Miranda, E. Bertero, V. V.1989The Mexico earthquake of September 19, 1985 -- performance of low-rise buildings in Mexico City during the 1985 Michoacan earthquakeEarthquake SpectraVol. 51, pp. 121-143. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; lowrise structures; dynamic properties; Mexico; building codes; earthquakes; Reinforced concrete structures; Strength; Ductility; Static analysis; Reinforced concrete slabs; Masonry walls; Masonry; infill panels; panels; StiffnessAn analytical study is presented of two lowrise reinforced concrete buildings designed according to the Mexican building code in force during the 1985 earthquake. Static and dynamic analyses were performed. The dynamic characteristics, particularly the strength and ductility of the buildings, were assessed. Special attention was paid to the influence of the slab on the strength and stiffness of the floor system when determining the nonlinear behavior of the members as well as the overall dynamic characteristics and global behavior of the buildings. The effect of adding different masonry infill distributions was studied. The conclusions drawn explain the observed behavior of such structures in Mexico City during the earthquake.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395/F?^4Gomez, A. et al.,1989uThe Mexico earthquake of September 19, 1985 -- response and design spectra obtained from earthquake-damaged buildingsEarthquake SpectraVol. 51, pp. 113-120. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; response spectra; design spectra; Mexico; building codes; earthquakes; Static analysis; Mexico earthquakes; Response spectrum analysis; Modal analysis; Damage; Mexico City; structural design spectra; Earthquake-Resistant DesignThe resistant shear force of 13 buildings damaged in the earthquake was determined by static and dynamic analyses. Results of the static analysis suggest the advisability of increasing the shear base coefficient of the 1987 Mexico City Building Code RDF87 from 0.4 to 0.6 in high seismicity zones. However, results o slabs; Reinforced concrete slabs; nonlinear analysis; dynamic properties; Joints; flat plate-column; reinforced concrete slab-column; Waffle slabs; Shear wall-frame interaction:This paper analyzes the seismic performance of a 15-story waffle flat-plate building affected by the earthquake. The paper also evaluates the adequacy of present analytical methods for predicting observed damage and response. A model is proposed to define the seismic strength of the supplied slab for nonlinear analysis. The results from this analysis are compared with the observed seismic behavior of the building. In particular, the distribution of computed maximum rotational ductility demands on slabs agrees well with observed maximum slab damage in the building.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395NF?[4Smolka, A. Berz, G.1989sThe Mexico earthquake of September 19, 1985 -- an analysis of the insured loss and implications for risk assessmentEarthquake SpectraVol. 51, pp. 223-248. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; seismic risk; insurance; Mexico; earthquakes; structural damage; Mexico earthquakes; Earthquake intensities; Residential buildings; Commercial structures; Mexico City; Damage; Earthquakes as Natural DisastersThis study is organized into three parts: (1) the results and universal validity of a statistical evaluation of insured losses in the Mexico earthquake; (2) the multiple seismological, geotechnical, and risk factors that contributed to the damage pattern; and (3) a general discussion of loss ratios and insurance tariffs, including the worldwide threat of catastrophe and long-term effects using the Mexico and other recent earthquakes as a reference. In particular, the problem of regionally representative modified Mercalli intensity degrees in the Mexico earthquake is addressed in view of the relatively low loss ratios observed, which did not exceed 10 percent in zone C or 5 percent in the coastal area.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395~OF?\4Espinosa-Aranda, J. M. et al.,1989XThe Mexico earthquake of Ts the Pino Suarez complex, in which one 21-story building collapsed onto a 14-story building and two other 21-story buildings were severely damaged. The behavior of these buildings and two other case studies are analyzed. Utilizing simplified structural models and considering the actual rather than code design strength of the buildings, conclusions are drawn on the ductility demands imposed on steel buildings in Mexico City.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?W4Foutch, D. A. et al.,1989qThe Mexico earthquake of September 19, 1985 -- case studies of seismic strengthening for buildings in Mexico CityEarthquake SpectraVol. 51, pp. 153-174. Feb.?Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; strengthening; Mexico; earthquakes; Reinforced concrete frames; Steel; bracing; Composite structures; Infill walls; Reinforced concrete walls; Forced vibration tests; Multistory structures; Repairs; Steel frames; Braced frames; Steel-reinforced concrete structuresThe earthquake destroyed several hundred buildings and took thousands of lives. Two buildings in the most severely damaged part of the city experienced strong shaking but suffered only slight damage. These reinforced concrete frame buildings had been retrofitted with steel bracing systems and infill reinforced concrete walls prior to the earthquake. Forced vibration tests, analytical studies, and geotechnical investigations for each building have been conducted. The results indicate that the steel bracing systems strengthened the buildings and stiffened them, moving their natural periods away from the 2.0-second predominant ground period in that part of the city. Implications for the design of strengthening systems have been determined.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?X4Sordo, E. et al.,1989sThe Mexico earthquake of September 19, 1985 -- ductility and resistance requirements imposed on a concrete buildingEarthquake SpectraVol. 51, pp. 41-50. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; concrete structures; Mexico; earthquakes; dynamic properties; nonlinear response; Waffle slabs; nonlinear analysis; Story drift; Linear response; Damping; Concrete; columns; shear walls; Ductility; DamagewThis paper describes a study of a 12-floor concrete building with a waffle-slab system located 300 m from the accelerator at Secretaria de Comunicaciones y Transportes (SCT) in Mexico City. The reduced seismic coefficient associated with the failure of the critical story is calculated by a linear dynamic analysis that reproduces the earthquake damage in the real structure. The ductility factor associated with the damaged stories is obtained through a step-by-step nonlinear dynamic analysis. Finally, the peak value of the SCT maximum ordinate for spectral response corresponding to 5 percent of critical damping is determined.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?Y4Rosenblueth, E. et al.,1989[The Mexico earthquake of September 19, 1985 -- design spectra for Mexico's Federal DistrictEarthquake SpectraVol. 51, pp. 273-291. Feb.Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; design spectra; Mexico; building codes; earthquakes; structural design spectra; Mexico City; Fourier spectra; Response spectra; Soil conditions; Damage; Earthquake-Resistant DesigneThe methods are described to obtain seismic design spectra adopted for different zones of Mexico's Federal District in the 1987 building code. The paper explains the two approaches followed in the study, deterministic and probabilistic. The assumptions adopted are presented and justified, and several aspects recommended for detailed study are pointed out.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 k[F?Z4Rodriguez, M. Diaz, C.1989~The Mexico earthquake of September 19, 1985 -- analysis of the seismic performance of a medium rise waffle flat plate buildingEarthquake SpectraVol. 51, pp. 25-40. Feb.BGuerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; flat-plate structures; Mexico; building codes; earthquakes; nonlinear response; Du s; 1984; Morgan Hill; California earthquake; Apr. 24; Fourier spectra; Mathematical models; Displacements (structural); Gymnasia; Colleges; Educational institutions; Diaphragms; Time historiesF?S4+Whittaker, A. S. Uang, C. M. Bertero, V. V.19899Seismic testing of eccentrically braced dual steel framesEarthquake SpectraVol. 52, pp. 429-449. MayCBraced frames; linear response; building codes; Steel frames; Multistory structures; United States; U.S.-Japan cooperative research; Japan; Japan-U.S. cooperative research; Story drift; Energy dissipation; frames; Energy absorption; Stiffness; Eccentric bracing; response; Pseudodynamic tests; Buckling; Shaking table testsLTwo six-story eccentrically braced dual steel systems (EBDSs) were tested as part of the U.S.-Japan Cooperative Earthquake Research Program. The first, a full-scale structure (prototype), was pseudodynamically tested in the Large Size Structures Lab. of the Building Research Inst. in Tsukuba, Japan. The second, a similitude-scaled replica of the first, was tested on the earthquake simulator at the Univ. of California at Berkeley. The prototype was designed for the minimum earthquake forces specified by the 1981 Japanese Aseismic Code and also satisfied the current United States regulations. The performance of the EBDS (both prototype and model) was outstanding in terms of elastic strength and stiffness during minor shaking and its ability to absorb and dissipate energy without strength or stiffness degradation during severe shaking.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?T4Meli, R. Avila, J. A.1989QThe Mexico City earthquake of September 19, 1985 -- analysis of building responseEarthquake SpectraVol. 51, pp. 1-17. Feb.9Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; nonlinear structures; Mexico; earthquakes; Reinforced concrete structures; nonlinear response; Waffle slabs; Reinforced concrete shear walls; Office buildings; Response spectra; linear; nonlinear; Acceleration; Design spectra; Energy dissipation; Mexico CityThe response of simple structural models to the peculiar ground motions recorded in the lake bed area of Mexico City was analyzed to explain the performance of typical buildings during the 1985 earthquake. The results for one degree-of-freedom systems with different kinds of inelastic behavior show that when hysteresis loops remain stable under several cycles of large inelastic deformations, structural response reduces significantly. Even so, if the hysteresis loops show some degradation of strength for large displacements, response increases sharply for the same critical periods. Results for multidegree-of-freedom systems show large concentrations of ductility demands at lower stories. Results resemble observed behavior and measurements under low-amplitude ambient vibrations.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?U40Goodno, B. J. Craig, J. I. Zeevaert-Wolff, A. E.1989TThe Mexico earthquake of September 19, 1985 -- behavior of heavy cladding componentsEarthquake SpectraVol. 51, pp. 195-222. Feb.Damage; Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; cladding; Mexico; nonstructural elements; earthquakes; response; Experimentation; United States; Finite element method; Repairs; Prestressed concrete; Reinforced concrete; Stiffness; Interaction; cladding-structureA combined field study of building cladding performance during the earthquake and supporting analytical and experimental studies of cladding systems typical of those used in Mexico City are described. The results include (1) the nonstructural damage survey and evaluation for selected buildings, (2) the laboratory tests of cladding connections, and (3) the analytical evaluation of a case study building for cladding-structure interaction effects. This study is complementary to earlier work involving laboratory testing and analytical studies of cladding connection designs typical of U.S. practice. The intent is to provide a balanced and coordinated attack on the problem of nonstructural performance, of benefit to both Mexico and the United States.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395gF?V4Osteraas, J. Krawinkler, H.1989JThe Mexico earthquake of September 19, 1985 -- behavior of steel buildingsEarthquake SpectraVol. 51, pp. 51-88. Feb.Damage; Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; steel structures; Mexico; earthquakes; nonlinear response; Multistory structures; Ductility; Steel frames; Welds; Fractures; Steel; bracing; Failure; Time history analysis; Braced structures`During the earthquake, about 60 post-1957 multistory steel buildings in Mexico City were subjected to a severe test, resulting in minor to moderate damage. The notable exception wa  Response spectra; nonlinear; Nonlinear oscillators; response; Time domain analysis; Hysteresis; Ground motion; oscillators; Single degree-of-freedom structures; nonlinear response; Ductility; nonlinear structures; Simulation; accelerograms; Time history analysis; Rocks; Soils; Western United States; SitesCThe validity of evaluating the inelastic response of a structure subjected to an artificial accelerogram in lieu of a suite of eight recorded ground motions is determined by analyzing the inelastic response of single degree-of-freedom oscillators over a range of frequencies from 1.0 to 10.0 Hz. A normalization procedure to minimize the dispersion in the ductility response of the oscillators subjected to the recorded ground motions is investigated. The artificial accelerogram is derived by superimposing closely spaced sine waves in order to match a target response spectrum.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395-F?I4 Wyllie, L. A., Jr. Filson, J. R.1989(Armenia earthquake reconnaissance reportEarthquake Spectra'Vol. Special Suppl, pp. 175 pages. Aug.8Lifeline systems; damage; Industrial plants; Large-panel structures; Precast concrete structures; Stone; Spitak region; Armenian S.S.R.; U.S.S.R. earthquake; Dec. 7; 1988; Union of Soviet Socialist Republics; earthquakes; building codes; Accelerograms; U.S.S.R. earthquakes; Seismicity; Caucasus region; U.S.S.R.This publication is a compilation of discrete preliminary reports by twelve of the EERI reconnaissance team members on the Dec. 7, 1988, Armenian earthquake. The chapter titles follow: 1--Seismology; 2--Surface faulting: a preliminary view; 3--Effect of site conditions on ground motion and damage; 4--Strong motion records; 5--Geotechnical aspects; 6--Performance of engineered structures; 7--Construction codes and standards in the Armenian Soviet Socialist Republic; 8--Performance of industrial facilities; 9--Performance of lifeline systems; 10--Search and rescue; 11--Social impact and emergency response; 12--Medical and healthcare aspects; and 13--Summary and conclusions.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?J4%Riddell, R. Hidalgo O, P. Cruz, E. F.1989WResponse modification factors for earthquake resistant design of short period buildingsEarthquake SpectraVol. 53, pp. 571-590. Aug.Response spectra; Linear structures; Nonlinear structures; Single degree-of-freedom structures; Elastoplastic analysis; Ductility; Design spectra; nonlinear; Building codes; Vibrations; structural response; Design; Structural Dynamics-Most recent seismic codes include response modification factors in the definition of the equivalent lateral forces that are used for the design of earthquake-resistant buildings. The response modification factors (R) are used to reduce the linear elastic design spectrum to account for the energy dissipation capacity of the structure. The evaluation of the response modification factors for various sets of earthquake records and ductility factors is presented. Special attention is given to the short-period range where the reduction of linear elastic response spectra is smaller than the values for intermediate- and long-period structures. An idealized and simple variation of the response modification factor as a function of the period of vibration, suitable for seismic code formulation, is also presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395}F?K4Gibbs, J. F. Roth, E. F.1989tSeismic velocities and attenuation from borehole measurements near the Parkfield prediction zone, central CaliforniaEarthquake SpectraVol. 53, pp. 513-537. Aug.Central California; wave attenuation; S-waves; California; central; Spectra; shear waves; Attenuation; Parkfield; Velocity; wave; San Andreas fault; Sands; waves; Gravels; Engineering Seismology4Shear (S)- and compressional (P)-wave velocities were measured to a depth of 195 m in a borehole near the San Andreas fault, where a recurrence of a moderate Parkfield earthquake is predicted. S-wave velocities were determined from orthogonal directions of the S-wave source to show the velocity differences.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?L4Perbix, T. W. Burke, P.1989@Toward a philosophy for seismic retrofit: the Seattle experienceEarthquake SpectraVol. 53, pp. 557-569. Aug."Wood; frames; Masonry walls; strengthening; Composite structures; Residential buildings; School buildings; Wooden structures; Brick structures; Shear walls; Office buildings; Seattle; structural strengthening; Washington; Humans; Building codes; Socioeconomic aspects; Repairs; Seismic risk+By examining the seismic retrofit of three buildings in Seattle, life safety, building usefulness both before and after seismic events, and economic consequences are examined in light of the professional and regulatory atmosphere. The work therefore proposes a seismic retrofit design philosophy for discussion and possible use as a premise for development of codes. The proposed philosophy coordinates retrofit in a way that meets the needs of designers and regulators who are currently forced to make social policy in their everyday design interactions.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?M4Christian, J. T.1989:Generating seismic design power spectral density functionsEarthquake SpectraVol. 52, pp. 351-368. MayPower spectra; density functions; Response spectra; Design spectra; Single degree-of-freedom structures; response; United States; building codes; Integration; Microcomputer applications; power spectra density functions; SPEED; Response spectrum analysis; Structural DynamicsmIt is often difficult to apply a response spectrum when dealing with multiple degrees-of-freedom or complex representations of structural behavior. The power spectral density function, a more fundamental description of the frequency content of ground motion, has found increasing use. Although in theory the response spectrum and the power spectral density are closely related, in practice it has proven difficult to compute one from the other. Two integration schemes described in the literature have been implemented in an interactive microcomputer program, SPEED, and are found to give substantially identical results.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395.(F?N4,Roeder, C. W. Carpenter, J. E. Taniguchi, H.1989=Predicted ductility demands for steel moment resisting framesEarthquake SpectraVol. 52, pp. 409-427. MaySteel frames; dynamic properties; nonlinear response; Ductility; frames; Steel; beam-column assemblies; Damping; Axial loads; Hysteresis; United States; Structural DynamicspRecent changes to United States seismic design provisions permit the use of steel weak column-strong beam moment-resisting frames. This design concept has not been used in the past because it results in plastic hinges in the columns during moderate or extreme earthquakes. This paper shows the results of inelastic dynamic response calculations using a weak column frame and a comparable strong column system. The results show that the ductility demand is much greater for the weak column-strong beam framing system for some acceleration re ings within 20 km of the fault, adding significantly to the near-field, large-magnitude database of ground motions. Ground motions were recorded by the Kandilli Observatory and Earthquake Engineering Research Institute of Bogazici University (Kandilli), the Earthquake Research Department of the General Directorate of Disaster Affairs (ERD), and Istanbul Technical University (ITU). Currently, nine recordings are available from Kandilli, ten recordings are available from ERD (within 200 km of the fault rupture), and four recordings are available from ITU. Site classifications for the strong-motion stations were obtained directly from the institutions operating the stations. This chapter compares the intensity, duration, and frequency content of the recorded ground motions with currently available relationships that predict these ground-motion parameters. Response spectra currently recommended by the 1997 Uniform Building Code (ICBO 1997) are compared with response spectra from the recorded motions. Near-fault rupture directivity and the effect of soil conditions on the recorded ground motions are discussed. Damage patterns in various affected areas are presented and correlations are made between damage patterns and soil conditions. F?j2Safak, Erdal et al.,2000~Kocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 5 -- recorded main shock and aftershock motionsEarthquake Spectra#Vol. 16, Suppl. A, pp. 97-112. Dec.Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; accelerograms; Adapazari; Turkey; aftershocks; Avcilar; amplification; Dilovasi; Korfez; ground motion and soil conditions; Pseudo-acceleration response spectra; Soft first stories; P-delta effectsThe magnitude M subscript w = 7.4 Kocaeli earthquake produced one of the best sets of near-field records from a large strike-slip earthquake. The records were obtained from the seismic networks installed and operated by Kandilli Observatory and Earthquake Research Institute (KOERI) of Bogazici University, Istanbul Technical University (ITU), and the General Directorate of Disaster Affairs (GDDA) of the Ministry of Public Works and Settlement. These institutions compiled and processed the data within a week of the earthquake and made the plots and digital copies of the records available on their Web sites. Thirty-seven strong motion stations recorded the earthquake. The earthquake also triggered the structural arrays installed and operated by KOERI in the Haghia Sophia Museum and the Suleymaniye Mosque in Istanbul. Immediately after the earthquake, teams from Turkey (KOERI), the United States (the U.S. Geological Survey, Columbia University, and the University of Southern California), Germany, France, and Japan deployed portable instruments to record aftershocks in and around the damaged towns and the epicentral region. The aftershock data is being compiled and processed and will be made public. ~1TF?k2Anderson, John G. et al.,2000|Kocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 6 -- implications for seismic hazard analysisEarthquake Spectra$Vol. 16, Suppl. A, pp. 113-137. Dec.$Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; accelerograms; Duzce; Nov. 12; near-field ground motion; Gebze strong-motion station; Turkey; Sakarya strong-motion station; North Anatolian fault; Strong-motion instrument arrays; damage and soil conditions; Rocks; acceleration; Site effectskIn 1999, Turkey experienced two major earthquakes on the North Anatolian fault system. The first, with moment magnitude 7.4 on August 17, 1999, ruptured the fault for at least 140 km from Golcuk to Melen Lake (Golu). The second, with moment magnitude 7.1 on November 12, 1999, ruptured an additional 30 km of the fault from Melen Lake (Golu) to Kaynasli. The Turkish Ministry of Disaster Affairs maintains a sparse strong motion network, with stations in several of the major cities in the region. In addition, the Kandilli Observatory and Earthquake Research Institute of Bogazici University in Istanbul maintains a network in the greater Istanbul area. Between these two networks, there are at least 23 strong motion records for the Kocaeli earthquake within 200 km of the fault (see chapters 4 and 5), including seven that will be highly significant for deciphering the source processes. The Duzce earthquake, with the shorter fault, generated two highly significant strong motion records in the near field from the permanent stations. A temporary deployment by Columbia University obtained additional accelerograms on a profile across the western end of the surface faulting. The purpose of this chapter is to summarize the strong motion data from the nearest stations and to document information that is significant for its interpretation. In the course of this study, the team visited the most significant strong motion stations and adjacent parts of the fault. All locations were verified using a handheld Global Positioning System (GPS) receiver. Thus, instrument housing characteristics are described, a preliminary impression of site conditions i U94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?Q4(Peng, M. H. Elghadamsi, F. E. Mohraz, B.1989FA simplified procedure for constructing probabilistic response spectraEarthquake SpectraVol. 52, pp. 393-408. MayResponse spectra; Single degree-of-freedom structures; analysis; Displacements (structural); Soil-structure interaction; Alluvium; Rocks; Soil conditions; ground motion; Spectra; Damping; Acceleration; Geologic conditions; Linear structures; Structural DynamicsA simplified procedure is provided for computing the probabilistic maximum response of a linear single degree-of-freedom system subjected to earthquake ground motion. The formulation uses the root-mean-square (rms) response of the system and a probabilistic peak factor which is modified to account for the wide-band characteristics. The modification uses a set of damping-dependent coefficients obtained from correlating the peak factor with the ratio of the maximum response to the rms response from accelerograms recorded on alluvium and rock. The procedure incorporates the influence of soil condition and strong-motion duration as parameters in computing response spectra.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395|F?R4Celebi, M. et al.,1989/Seismic response of a large-span roof diaphragmEarthquake SpectraVol. 52, pp. 337-350. MayRoofs; response; Plywood; Saratoga; California; Northern California; earthquake  d, T. F. et al.,1989SSlotted bolted connections in aseismic design for concentrically braced connectionsEarthquake SpectraVol. 52, pp. 383-391. MayBraced frames; nonlinear response; Steel frames; Energy dissipation; Hysteresis; joints; Experimentation; bolts; Steel joints; Building codes; Earthquake-Resistant DesignThe use of concentrically braced steel frames to satisfy lateral force requirements is a common design practice in regions of strong seismicity. Such frames provide an efficient means for fulfilling the dual objectives of earthquake-resistant design, damage control, and collapse prevention. While tensile yielding and inelastic buckling of bracing elements provide the basic energy-absorbing mechanism, there are inherent problems with member behavior under multiple cycles of inelastic deformations. Inelastic energy dissipation, however, may also be provided by friction resistance in slotted bolted connections, thus eliminating the need for inelastic member buckling. Limited laboratory tests indicate that this may be a viable alternative both for new structures and in upgrading structures.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, mined from the viewpoints of geology, seismic history, and strong ground motion. The best available data are compiled on slip rates and recurrence times for all major faults in Southern California and northern Baja California. Those possible fault segments that might rupture in single earthquakes are identified, and repeat times are obtained for events consistent with (or at least not contradicted by) trenching studies. Geological data are combined with an attenuation model to obtain an estimate for the occurrence rate of various levels of peak ground acceleration in downtown San Diego from events with moment magnitude greater than about 6. The authors find that peak accelerations of 10 percent g to 20 percent g are expected about once every 100 years.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395-%F?P4Fitzgeral cords. The required ductility is then compared for the two structural systems and the ductility is compared to the results of experiments. The comparison suggests that the weak column system may not be able to develop the required ductility. Results presented should help to define the viability and applicability of the weak column system.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395'*PF?O4,Anderson, J. G. Rockwell, T. K. Agnew, D. C.1989LPast and possible future earthquakes of significance to the San Diego regionEarthquake SpectraVol. 52, pp. 299-335. MaySan Diego; California; faults; seismic risk; Southern California; Attenuation; southern; Isoseismal maps; earthquakes; Accelerograms; Earthquake hazards; Ground motion; San Jacinto fault; Imperial fault; San Andreas fault; Baja California; Mexico; Crustal slip; return periodsCThe potential for earthquakes in the San Diego, California, region is exa k framesEarthquake SpectraVol. 53, pp. 495-511. Aug.Links; Strength; joints; Beams; design; Bracing; Columns; Axial loads; Braced frames; building codes; Steel frames; Ductility; Steel joints; Earthquake-Resistant DesignSeismic-resistant eccentrically braced frames are becoming a widely used lateral-resisting system for steel buildings, with even wider application anticipated as design requirements are put into building code format. This paper addresses a number of eccentrically braced frame design issues, which in the opinion of the authors are inadequately considered either in current practice or in the emerging code provisions. The overall design philosophy for eccentrically braced frames is reviewed, with specific reference to the concept of capacity design. Application of capacity design principles assures that yielding will be primarily restricted to the ductile link elements. Furthermore, through careful choice of frame geometry and link length at the preliminary states, many potential design difficulties can be avoided. The paper also presents some important observations from experimental work currently under way on eccentrically braced frames with long, flexural yielding links.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?H4Barenberg, M. E.1989CInelastic response of a spectrum compatible artificial accelerogramEarthquake SpectraVol. 53, pp. 477-493. Aug.2 .Bridges; design standards; San Fernando; California earthquake; Feb. 9; 1971; highway bridges; Tunnel linings; Transportation systems; retrofittingAdvances over the past fifty years in earthquake engineering as applied to transportation structures are discussed with focus on seismic loading criteria, dual strategy of design, modeling and analysis, design detailing, and assessment of seismic performance. Current state-of-the-art methodologies used in the seismic design of bridges are reviewed, pointing out areas of needed improvements, including the characterization of free-field ground motions for functional and life-safety levels of design, evaluation of soil-foundation-structure interaction effects, modeling of structural components for seismic demand and capacity evaluations, and seismic performance assessments. Advancing the state of the art of bridge engineering through future research, both analytical and experimental, and advancing the state of the practice through the development of new performance-focused code specifications are encouraged.F?Z2Mays, Timothy W.2001SEERI Student Paper Award 2000: Seismic design of lightweight metal building systemsEarthquake SpectraVol. 171, pp. 37-46. Feb.American Inst. of Steel Construction (AISC); design standards; Lightweight metal structures; Steel moment-resisting frames; linear time history analysis; Central United States; Eastern United States; Moderate-seismicity regionsAs a result of failures uncovered after the Northridge earthquake, the AISC Seismic Provisions for Structural Steel Buildings has become extremely stringent in its design provisions for moment frame structures. Although the changes are justified, they are not necessary for every type of building system. Some structures can be safely designed to resist earthquake forces elastically without concern of structural collapse. Metal buildings are typically lightweight, and small inertia forces from the design earthquake will not usually result in an inelastic response of a system that is properly designed to resist wind forces. In this paper, metal building systems are analyzed using an equivalent lateral force method and a linear time history analysis to show that typical metal building systems will respond elastically to the design earthquake. Specifically, using the International Building Code along with the aforementioned document, it is shown that, for lightweight metal building structures, adherence to the AISC Seismic Provisions for Structural Steel Buildings is not required in most cases, except for locations on the West Coast and a few regions east of the Rocky Mountains. Elastic design methodology is discussed and design recommendations applicable to metal building systems are provided.F?[2'Sanchez-Silva, Mauricio Garcia, Libardo2001EEarthquake damage assessment based on fuzzy logic and neural networksEarthquake SpectraVol. 171, pp. 89-112. Feb.>Quindio; Colombia earthquake; Jan. 25; 1999; damage assessmentPotential damage assessment is fundamental for defining mitigation procedures and risk management strategies. Damage assessment involves the difficulties of defining, assessing, and modeling the variables involved, as well as handling uncertainty. Seismic damage estimation of structures not only depends on the behavior of the structural system, but involves other factors, which differ in nature. This paper presents a methodology for damage assessment of structures that combines systems theory, fuzzy logic, and neural networks. A feed-forward neural network supported by a systemic organization of information is used to assess the expected structural damage for a given earthquake. The methodology provides a very useful environment to consider the context of the building structure. The network has been trained using the damage observed in the recent earthquake that occurred in central Colombia. Several sets of structures were evaluated and the results compared to the damage observed. The model proved to be highly reliable and a good representation of experts' opinions. Computer software, named ERS-99, was developed and is currently being used for teaching and consulting purposes.RF?\2=Krinitzsky, Ellis L. Chowdhury, Mostafiz R. Al-Chaar, Ghassan2000dKocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 10 -- effects on damsEarthquake Spectra$Vol. 16, Suppl. A, pp. 227-234. Dec.Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; rockfill dams; earth dams; Duzce; Nov. 12; Gokce Dam; Yalova area; Turkey; response; Kirazdere Dam; Yuvacik area; damage; Hasanlar Dam; Duzce area; Maximum horizontal accelerationrOnly two dams experienced earthquake shaking with a peak horizontal acceleration (PHA) of 0.2 g. These were Gokce Dam near Yalova, where the PHA was around 0.2 g, and Kirazdere Dam, southeast of Izmit, where the PHA was as much as 0.4 g. An additional dam, Hasanlar, experienced about 0.2 g from the Duzce earthquake. All the dams are earth embankments on bedrock. None of the dams had any significant damage. The behavior of Kirazdere Dam, which is located practically at the epicenter of the 1999 Kocaeli earthquake, is of particular interest. The dam experienced a powerful earthquake of M subscript s = 7.8 without damage.F?]2Aschheim, Mark et al.,2000mKocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 11 -- performance of buildingsEarthquake Spectra$Vol. 16, Suppl. A, pp. 237-279. Dec.qIzmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; damage; Turkey; building codes; Golcuk; reinforced concrete shear walls; Adapazari; multistory reinforced concrete structures; The Wagon Factory (Turkiye Vagon Sanayii A.S.); Adapazari area; Retrofitting; Arifiye; precast concrete structures; Masonry-reinforced concrete infill wall-frame interaction; Industrial plants^The 1999 Kocaeli, Turkey, earthquake caused severe damage or collapse of buildings in seven provinces over a 250-km distance from Istanbul to Bolu. As many as 70% of the buildings in portions of the cities of Adapazari, Golcuk/Degirmendere, Yalova, Izmit, Topcular, and Kullar were severely damaged or collapsed, as described in chapter 12. Nearly all the fatalities and injuries can be attributed to building collapse. As of January 2000, the government Crisis Management Center reported 19,355 buildings had collapsed and 14,626 buildings were irreparably damaged in the August 17 earthquake. Turkey's National Security Council estimated 200,000 people were made homeless. Preliminary reports had suggested 115,000 buildings were damaged beyond repair and more than 500,000 people made homeless. Precise estimates of losses are not easily made; considering the total area of documented damage and the average cost of building replacement yields an estimate of direct losses of about US$5 billion. This chapter discusses the building inventory in the damaged region, its construction, building code requirements, and the damage incurred during the earthquake. Damage to industrial structures is described in this chapter and in chapter 14 in the context of operational effects. Chapter 15 examines the reasons for the apparent vulnerability of the building stock in Turkey.F?^2Johnson, Laurie A. et al.,2000Kocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 12 -- damage survey approach to estimating insurance lossesEarthquake Spectra$Vol. 16, Suppl. A, pp. 281-293. Dec.rIzmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; loss estimation methodologies; Insurance; Earthquake intensities$The magnitude 7.4 Kocaeli earthquake was one of the few large-magnitude events to strike a highly industrialized region of the world in the last fifty years. The disaster was the lead story on world news networks for nearly a week, and much of the coverage focused on the rescue efforts under way at individual residential buildings. A regional, spatially integrated view of the earthquake's effects was lacking initially. International aid agencies and global reinsurers needed this perspective to better understand losses and needs and to develop appropriate response strategies. A more complete understanding of the Kocaeli earthquake's social and economic consequences required a more comprehensive survey of the damage and the losses than was initially provided by investigators and the earthquake engineering and seismological laboratories in Turkey. The first sections of this chapter explore a methodology for estimating losses for the insurance industry: estimating shaking intensity by quantitative surveys of building damage; valuing insured exposure in the areas of highest shaking; surveying exposures to determine average loss levels; and generating a preliminary loss estimate. The chapter also discusses how this information was used and how the preliminary loss estimate compared with actual losses.F?_2Boulanger, Ross W. et al.,2000yKocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 13 -- performance of waterfront structuresEarthquake Spectra$Vol. 16, Suppl. A, pp. 295-310. Dec. Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; harbor facilities; waterfront structures; Port of Derince; Derince; Turkey; Tuzla Port; harbors; Haydarpasa Port; Istanbul; Golcuk Naval Base; Golcuk; Yarimca Petrochemical Complex; Korfez; Petkim petrochemical facilityThe Kocaeli earthquake caused extensive damage to the numerous waterfront piers and port facilities around Izmit Bay. The largest nonmilitary port damaged by the earthquake was at Derince, while the port at Tuzla (west of Derince) experienced only minor damage and the port at Haydarpasa (close to Istanbul) was undamaged. The military port at Golcuk on the southern waterfront was also damaged, including damage due to surface fault rupture as described in chapter 2. This chapter describes damage at these and other specific ports and piers. IDF?`2-Johnson, Gayle S. Aschheim, Mark Sezen, Halil2000jKocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 14 -- industrial facilitiesEarthquake Spectra$Vol. 16, Suppl. A, pp. 311-350. Dec.Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; industrial plants; Petrochemical plants; damage; Automobile manufacturing plants; Oil refineries; Korfez area; Turkey; Tupras oil refinery; Petkim petrochemical facility; Korfez; Yarimca Petrochemical ComplexThe epicentral area is home to about 40% of Turkey's heavy industry. There are several concentrated areas of industry surrounding the Sea of Marmara and Izmit Bay, extending to Adapazari. Substantial damage to industrial facilities was observed over a large geographic area. More than 25 companies from various industries in the Izmit and Adapazari areas were surveyed in the days immediately following the earthquake. The performance of these industrial facilities is relevant to other areas of the world because Turkey has many modern, engineered facilities, in many cases owned by multinational companies. The industrial facilities visited generally were constructed with much higher quality control than observed in the residential structures. This chapter summarizes observations relevant to the seismic performance of industrial facilities. Structural engineering aspects of industrial building performance are discussed in chapter 11. The damage was much more severe and extensive than seen in earthquakes with similar peak ground acceleration levels, with numerous examples of extended business interruption. Based on the type of structures damaged and the nature of the damage, it is likely that the long period motion and duration of the earthquake were major contributors to the extent of damage. This earthquake has pointed out many situations that might be encountered and hazards that might be faced during earthquakes of this magnitude, such as !of 0.5, 1, 2, 5, 10, and 20 Hz. Magnitude dependence of Sa/a is predicted and the effect of distance scaling is assessed.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395uF?F44Anagnostopoulos, S. A. Petrovski, J. Bouwkamp, J. G.1989AEmergency earthquake damage and usability assessment of buildingsEarthquake SpectraVol. 53, pp. 461-476. Aug.xBalkans; Field investigations; structural damage prediction; Seismic safety; structures; Seismic risk; Earthquake DamageAn earthquake damage inspection form and criteria for assessing earthquake damage and usability of buildings under emergency conditions are presented. These criteria and the inspection form are key elements of emergency inspection and have been based on recent experiences from damaging earthquakes in the Balkan region. They have been developed with a number of objectives in mind, notably for efficient use in the field and the reliable assessment of a building's capacity. Since the emergency inspections of building damage will be a large-scale operation, organizational aspects of this operation are discussed and specific recommendations are made.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395W2lF?G4Engelhardt, M. D. Popov, E. P.1989(On design of eccentrically braced  are used: (1) a planar linear model with classical damping and (2) a three-dimensional linear model consisting of rigid floor decks, where each floor is allowed three degrees-of-freedom--two orthogonal translations plus a rotation.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395hF?E4Silva, W. J. Green, R. K.1989Magnitude and distance scaling of response spectral shapes for rock sites with applications to North American tectonic environmentEarthquake SpectraVol. 53, pp. 591-624. Aug.Ground motion; models; Response spectra; Acceleration; Western North America; Eastern North America; Time histories; Random vibrations; Random processes; Oscillators; Rocks; Geologic conditions; Engineering SeismologyuResponse spectral shapes (Sa/a) computed from the band limited white noise ground motion model combined with random vibration theory are compared with shapes computed from western North America earthquakes recorded at rock sites. The comparisons are made at close distances and for moment magnitudes 4 1/2, approximately 5, 6, and 6 1/2. Predicted spectral shapes for eastern North America are compared with empirical results at frequencies of 1 and 10 Hz and with other random process models at frequencies  T. L. et al.,1989,A wedging system for downhole accelerometersEarthquake SpectraVol. 54, pp. 813-818. Nov.Stainless steel; Parkfield; California; accelerometers; Electric Power Research Inst. (EPRI); U.S. Geological Survey; Central California; Strong-motion instrument arrays; central; Coupling; Strong Motion SeismometryA wedging system for coupling downhole accelerometers into cased boreholes has been developed and deployed at an Electric Power Research Inst. (EPRI)/U.S. Geological Survey (USGS) instrument array located in the Cholame Valley near Parkfield, California. The wedging system allows downhole accelerometers to be set and retrieved by hand. With this system, accelerometers can be readily retrieved from cased holes for inspection, maintenance, or redeployment.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395:n(F?D4Lin, B. C. Papageorgiou, A. S.1989Demonstration of torsional coupling caused by closely spaced periods--1984 Morgan Hill earthquake response of the Santa Clara County BuildingEarthquake SpectraVol. 53, pp. 539-556. Aug.+Steel structures; dynamic properties; Steel frames; Multistory structures; Accelerograms; Mode shapes; Reinforced concrete structures; Coupling; torsional; Torsion; San Jose; California; Vibrations; Santa Clara County; Office buildings; Damping; Modal analysis; Stiffness; Three-dimensional analysisiThe parameters of the dominant modes of vibration of the steel-frame Santa Clara County Office Building in San Jose, California, are determined using the modal minimization method for structural identification. The optimal estimates of the model parameters are determined by minimizing a selected measure-of-fit between the responses of the structure and the model. Two types of models "ctural analysis; Response spectrum analysis; Static analysis;A summary of the different provisions existing in Chile is given. The codes related to earthquake engineering practice are divided into two major groups: the first defining the loads and actions, and the other dealing with material behavior, resistance, and detailing requirements. The overall characteristics of these codes are discussed. Special emphasis is given to the seismic design code provisions that define the level of earthquake action to expect, depending on building characteristics and site soil conditions. Two different analysis procedures are allowed: the equivalent lateral forces procedure in which torsion is considered through an amplification of the static torsion in the building and the standard response spectrum analysis method with a three degree-of-freedom per story model of the building. The maximum responses of the different modes are combined using a special combination rule. Additional restrictions are imposed for torsional effects and overall building deformations. Finally, the basic ideas under consideration for the revised code are presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395o F?@4Fahmi, K. J. Al Abbasi, J. N.19899Some statistical aspects of earthquake occurrence in IraqEarthquake SpectraVol. 54, pp. 735-765. Nov.Iraq; Earthquake catalogs; Seismicity; Earthquake magnitudes; magnitude-frequency relationships; Earthquakes; return periods; Earthquake intensities; Seismic risk; Seismology; Earthquake Risk_Owing to Iraq's unique geographic location, the eastern and northeastern parts are directly influenced by the seismic activity of the Tauros-Zagros tectonic zones. An earthquake data file containing nearly 550 entries from 1905-1984 is compiled and an analysis of completeness is performed using Stepp's model. It is observed that the file is complete for 4.8 Ms and greater over the whole 80-year sample of data while during the past 25 years this threshold drops to about 4.1 Ms. The "completed" data file is then employed in reevaluating the magnitude-frequency formula for the country. To further investigate earthquake occurrence, a simple statistical treatment is applied to a "constant-b" seismicity model whereby an increase in the frequency of occurrence of approximately 35 percent is identified in the latter half of the seismic history of the country.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?A4EERI Committe on Seismic Risk1989#The basics of seismic risk analysisEarthquake SpectraVol. 54, Nov., 1989, 675-702!Spectra; earthquake hazards; Acceleration; Attenuation; Ground motion; structural damage; Glossaries; Seismic risk; Los Angeles; Strengthening; Damage; Cost analysis; Insurance; Concrete structures; Framed structures; Loss analysis; Southern California; Seismic safety; Structural DynamicsaMethods of seismic risk analysis are discussed using a simple example of a hypothetical building in Los Angeles. The purpose of a seismic risk analysis is to make informed decisions about seismic safety, and this is illustrated by presenting the implications of several options available for a property owner to accept, insure, or mitigate seismic risk.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www. F?B4Blume, J. A. Rinne, J. E.1989Vibration characteristics and earthquake forces in a fifteen story building--an abridgement of an original paper by Edward C. Robison, 1950Earthquake SpectraVol. 54, pp. 633-654. Nov.pSan Francisco; tall buildings; Bending; dynamic properties; Vibrations; Northern California; Structural DynamicsAn abridgement of a classical mathematical solution is presented for twelve of fifteen translational modes of vibration of a 15-story building. This work was done by Edward C. Robison, from 1948-1950, just prior to the advent of the digital computer. He used seven place logarithms. The solution is expressed in terms of lateral forces of each of 12 modes at each of 15 floors derived from admissible solutions for eigenvalues from the characteristic equation. These forces, when normalized by a constant multiplying factor for each mode, add algebraically to the weight of each floor and to the over-all weight of the building--a principle illustrated by Robison's work and by a figure by Milton Ludwig published in a 1952 ASCE article.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 olina; earthquake; 1886; Acceleration; South Carolina earthquake; SeismologyLittle is known about the engineering seismological characteristics of eastern U.S. earthquakes because there are no strong-motion recordings of them. In particular, the peak ground acceleration, needed for structural design, is not available except through correlations with western U.S. earthquakes or modified Mercalli intensity data of unknown certainty. This paper estimates the peak ground acceleration experienced by St. Michael's Church during the 1886 earthquake based on conventional and probabilistic structural analysis. The 1886 earthquake, rated as modified Mercalli intensity X and magnitude 7, is the only historic strong-motion event greater than M = 5 that affected Charleston.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?64 Hays, W. W.1990GPerspectives on the International Decade for Natural Disaster ReductionEarthquake SpectraVol. 61, pp. 125-145. Feb.oUnited States; disaster planning; Intl. Decade for Natural Disaster Reduction; Earthquakes as Natural DisastersThis paper discusses the international goals of the 1990s for disaster preparedness and disaster mitigation. The United States will lead this cooperative effort and marshal its national resources to reduce the disaster potential of earthquakes, floods, windstorms, landslides, volcanic eruptions, tsunamis, and wildfires--natural hazards that cause annual losses of approximately 10 billion dollars in the United States and many times that throughout the world.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?74Atkinson, G. M. Boore, D. M.1990PRecent trends in ground motion and spectral response relations for North AmericaEarthquake SpectraVol. 61, pp. 15-35. Feb.Stochastic methods; ground motion; Eastern North America; Western North America; North America; eastern; western; Response spectra; Acceleration; Velocity; Rocks; Engineering SeismologyRecent ground motion relations which predict peak ground acceleration, peak ground velocity, and pseudo-relative velocity for rock sites in Eastern North America are based on a stochastic model whose parameters are indicated by seismological studies of earthquake source and attenuation processes. The validity of the model is verified by application to Western North America. The choice of model parameters is validated by comparison of model predictions with ground motion data for Eastern North America.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?84Adham, S. A. et al.,1990:Shear wall resistance of lightgage steel stud wall systemsEarthquake SpectraVol. 61, pp. 1-14. Feb.Steel frames; Light-gage steel; Cyclic loads; steel; shear walls; Strength; walls; Energy dissipation; Failure; Stiffness; Wind loads; Gypsum; wallboard; Experimentation; Buckling; Hysteresis; Damping; nonlinear response; Lateral loadsfExperimental investigations were conducted to evaluate the lateral load-deflection characteristics of light-gage steel stud/gypsum wallboard panel combinations subjected to lateral cyclic loads. In all, six 8 ft by 8 ft specimens were tested. The test results compared the maximum shear capacity of the gypsum wallboard with that available in the literature.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?94Beatley, T. Berke, P. R.1990]Seismic safety through public incentives: the Palo Alto seismic hazard identification programEarthquake SpectraVol. 61, pp. 57-79. Feb.Earthquake hazards; identification; California; northern; Masonry structures; Public policy; Palo Alto; Northern California; earthquake hazard identification; Seismic safety; Strengthening; Earthquakes as Natural Disasters; Governmental AspectsmLocated in the mid-Peninsula area south of San Francisco, Palo Alto has adopted a unique Seismic Hazard Identification Program which mandates the preparation and filing of seismic engineering reports and relies on the creation of incentives for voluntary retrofitting of seismically vulnerable buildings. The findings of this paper are based upon an extensive set of personal interviews conducted in September 1988 and an examination of city ordinances, staff reports, council minutes, and other relevant documents. The paper first describes the history of seismic policy in Palo Alto leading to the adoption of the seismic identification program. It then goes on to describe in detail the specifics of the Palo Alto program--its key provisions and requirements. The factors which influenced the adoption of the program and its final form and content are extensively discussed.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395YF?:4Bariola, J. Sozen, M. A.1990Seismic tests of adobe wallsEarthquake SpectraVol. 61, pp. 37-56. Feb.Shaking table tests; adobe; walls; nonlinear response; Free vibrations; Cracking; Rocking; Ground motion; Soil-structure interaction; Overturning; Acceleration; Failure; Structural DynamicsoThe object of this investigation was to study the stability of adobe walls during earthquakes. Nine earthquake simulation tests were made to investigate the influence of the following variables: (1) type of ground motion, (2) slenderness (thickness/height ratio), and (3) wall thickness. The dimensions of the specimens ranged from: 0.2 x 1.2 x 1.4 m through 0.4 x 1.2 x 2.8 m. Six specimens were tested with a soft-soil ground motion and another five with stiff-soil ground motion. An analytical model was used to calculate the susceptibility of the walls to overturning. Experimental and analytical results were compared.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?;4 Luft, R. W.1989"Comparisons among earthquake codesEarthquake SpectraVol. 54, pp. 767-789. Nov.rAmerican Natl. Standards Inst.; design standards; United States; U.S. Federal Emergency Management Agency; building codes; Lateral loads; structural design standards; Base shear; Frames; Reinforced concrete shear walls; Bearing walls; Reinforced concrete frames; California; New England; Seismic zoning; Applied Technology Council; ATC 3-06; Vertical loads; AccelerationThis review paper compares the ANSI (American Natl. Standards Inst.), NEHRP (Natl. Earthquake Hazard Reduction Program), SEAOC (Structural Engineers Assn. of California), and UBC (Uniform Building Code) code documents. A few essential differences among these documents are noted.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?<4Elton, D. J. Martin, J. R., II1989&Dynamic site periods in Charleston, SCEarthquake SpectraVol. 54, pp. 703-734. Nov.Maps; South Carolina; Sites; Soils; dynamic properties; ground motion; Charleston; earthquake; 1886; SHAKE; Computer applications; Strong-motion records; Accelerograms; Response spectra; Acceleration; Damage; Time histories; Soil conditions; Engineering SeismologyeA dynamic site period map for Charleston, South Carolina, is developed and presented using dynamic soil property data and a one-dimensional linear elastic computer program. The building damage distribution for the 1886 earthquake is compared with the distribution of dynamic site periods. An approximate method of estimating the linear site period is given.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23951F?=4 Schiff, A. J.1989/Lifeline response to the Tejon Ranch earthquakeEarthquake SpectraVol. 54, pp. 791-812. Nov.Southern California; earthquakes; 1988; aqueducts; Garlock fault; California; Circuit breakers; damage; Base isolation; Transformers; Lifeline systems; Electrical equipment; Water supply systems; Earthquake Damage%The vulnerability of important high-voltage switchyard equipment to low seismic input motions is discussed considering the failure of ten of sixteen 230 kV circuit breaker phases at the Edmonston Pumping Plant on the California Aqueduct during the June 10, 1988, Tejon Ranch earthquake in Southern California. Failures were primarily porcelain members. The failures were due to both the dynamic response of the members and to a lack of slack in the conductors connecting adjacent equipment. The aqueduct was out of service for four days until power was partially restored. Repairing or replacing all damaged equipment was expected to take from 6 to 8 weeks. The importance and vulnerability of high-voltage power equipment, the long time required to make repairs, and the difficulty in obtaining spare parts quickly emphasizes the need for cost-effective measures to improve the seismic response of this type of equipment. While this earthquake did not substantiate the effectiveness of a base isolation system installed on one circuit breaker, it did illustrate the need for instrumentation to evaluate the performance of these systems. Leaks developed at two Smith-Blain mechanical couplings in one of two 192-in. aqueduct siphons near the pump plant are evaluated considering ground deformations or inertial loads.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?>4 Brown, J. M.1989Inducing the private purchase of earthquake insurance through the involvement of the insurance and mortgage finance industries: an overview of potential problemsEarthquake SpectraVol. 54, pp. 655-660. Nov.:Insurance; Legal aspects; Earthquakes as Natural DisastersThis paper discusses the reluctance of residential property owners to purchase earthquake insurance and the obstacles that discourage the property damage/casualty insurance industry and/or the mortgage finance industry from stimulating the widespread private acquisition of earthquake insurance protection. One such obstacle is the risk of anti-trust violations should these industries actively engage in creating a widespread demand for earthquake insurance. Solutions are offered for this and other obstacles.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395{,F??4 Cruz, E. F.1989APresent state of seismic design and analysis regulations in ChileEarthquake SpectraVol. 54, pp. 661-674. Nov.?Steel structures; building codes; Reinforced concrete structures; Wooden structures; Reinforced masonry structures; Steel; Reinforced concrete; Wood; Reinforced masonry; Design spectra; Chile; Seismic loads; Soils; building loads; Sites; Torsion; dynamic stru fferent construction techniques. A summary is included of first cost studies on both new and existing buildings.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395uF?34'Filiatrault, A. Cherry, S. Byrne, P. M.1990mThe influence of Mexico City soils on the seismic performance of friction damped and base isolated structuresEarthquake SpectraVol. 62, pp. 335-352. MayMexico City; base isolation; damping devices; Mexico; response; Friction; Lowrise structures; Multistory structures; Steel frames; Steel structures; Sites; Soil conditions; Rubber bearings; Braced frames; Rocking; foundations; Clays; soil-structure interaction; Response spectraA seismic performance comparison is made of hypothetical low- and high-rise steel framed structures founded on both soft and stiff soils in Mexico City and equipped with (1) friction-damping devices, (2) base isolators, and (3) a combination of base isolators and friction-damping devices. The response of three structural systems, including soil-structure interaction, is examined for two specific sites in Mexico City: the stiff hills zone and soft lake bed zone.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395BF?44French, S. P. Rudholm, G. G.1990cDamage to public property in the Whittier Narrows earthquake: Implications for earthquake insuranceEarthquake SpectraVol. 61, pp. 105-123. Feb.Southern California; public buildings; Pasadena; California; Alhambra; Monterey Park; Los Angeles; Lifeline systems; damage; southern; Insurance; Whittier Narrows; California earthquake; Oct. 1; 1987; Earthquake DamageNearly half of the total damage caused by the Whittier Narrows earthquake of Oct. 1, 1987, occurred to public buildings--significant because these structures were eligible for private earthquake insurance and because this should be considered in developing a national earthquake insurance program. The earthquake provided an opportunity to observe the type and amount of damage sustained by public property and to investigate the funding mechanisms used to repair the damaged facilities. Repair of earthquake damage to public property, which includes public buildings and infrastructure lifelines, is largely funded by state and federal disaster relief payments./F?54Elton, D. J. Marciano, E. A.1990XGround acceleration near St. Michael's Church during the 1886 Charleston, SC, earthquakeEarthquake SpectraVol. 61, pp. 81-103. Feb.Response spectrum analysis; churches; Masonry; ground motion; Wood; Bending; Strength; Charleston; South Car mSuite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395HF?04Buckle, I. G. Mayes, R. L.1990FSeismic isolation: history, application, and performance--a world viewEarthquake SpectraVol. 62, pp. 161-201. May,Isolation; Base isolation; United States; France; Greece; Italy; Japan; New Zealand; People's Republic of China; Union of Soviet Socialist Republics; Bridges; Rubber bearings; Highway bridges; California; Utah; Nuclear power plants; Reinforced concrete structures; Girder bridges; Apartment buildingsThis paper reviews some of the history of seismic isolation and restates the basic elements of a modern isolation system. Progress worldwide is discussed, including the United States, China, France, Greece, Italy, Japan, New Zealand, and the Soviet Union. Directories of isolated structures in the United States, New Zealand, and Japan are also included. Finally, the performance of a selection of these structures during actual earthquakes is given.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?14-McKay, G. R. Chapman, H. E. Kirkcaldie, D. K.1990+Seismic isolation: New Zealand applicationsEarthquake SpectraVol. 62, pp. 203-222. MayIsolation; New Zealand; Base isolation; Energy dissipation devices; Reinforced concrete frames; Reinforced concrete structures; Bridges; Highway bridges; Steel; Railroad bridges; Rubber bearings; Earthquake-Resistant DesignThe application of seismic isolation to structures in New Zealand is discussed. Since 1973oMF?/4)Tajirian, F. F. Kelly, J. M. Aiken, I. D.19905Seismic isolation for advanced nuclear power stationsEarthquake SpectraVol. 62, pp. 371-401. MayBase isolation; nuclear power plants; Isolation; design; France; Europe; United Kingdom; Japan; United States; Seismic qualification; Rubber bearings; nonlinear response; dynamic properties; Response spectra; nonlinear; Vertical loads; Experimentation; Hysteresis; Buckling|To date, six large pressurized water reactor units have been isolated in France and South Africa, and several advanced nuclear concepts in the U.S., Japan, and Europe have incorporated this approach. It is recognized that to qualify and license an isolation system in the U.S. and Japan, a comprehensive testing program of isolation components and systems would be required. A major seven-year program was initiated in Japan in 1987 with the objective of establishing a qualified seismic isolation design for a large fast-breeder reactor to be constructed by 1990. In the U.S., two concepts which use steel-laminated elastomeric bearings for seismic isolation have been developed. One of these concepts is a novel system which provides three-dimensional isolation. An extensive test program of scaled prototype bearings to demonstrate their feasibility and effectiveness has been carried out.Earthquake Engineering Research Institute, 499 disruption considered.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395kSF?24&Mayes, R. L. Jones, L. R. Kelly, T. E.1990/The economics of seismic isolation in buildingsEarthquake SpectraVol. 62, pp. 245-263. May#Commercial structures; isolation; nonlinear analysis; cost analysis; structural damage prediction; Base isolation; structural damage; Damage; prediction; Insurance; Legal aspects; Repairs; Construction; California; Manufacturing plants; Hospitals; Steel frames; Steel structures; Los AngelesThe economic issues of seismic isolation are discussed considering the four principal cost factors that should be evaluated: (1) construction costs, (2) earthquake insurance premiums, (3) physical damage that must be repaired, and (4) disruption costs, loss of market share, and potential liability. Methods are presented for estimating the difference in the cost of earthquake damage using di idges, three large buildings, and a few other structures have been protected with this technique. Numerous energy-dissipating devices have been developed and tested and six of these designs are discussed that have been incorporated in the seismic isolation systems of the structures built. Development work on seismic isolation devices is continuing in New Zealand; and contact with specialists from other countries, in particular Japan and the United States, is being maintained with the long-term benefits of reduced seismic damage and  ards; mitigation; Earthquakes as Natural Disasters; Governmental AspectsMost of California's population and industry are located in zones of high seismicity, and the U.S. Federal Emergency Management Agency (FEMA) estimated that a 7.5 to 8.3 Richter magnitude earthquake in an urban area could cause up to 60 billion dollars in damage. Such an earthquake could cripple the state's public and private economies, the sixth largest in the world, and adversely affect the world market. Building practices in California offer only minimal protection from seismic damage; however, new technologies, such as seismic isolation, can mitigate damage and are becoming available to government and industry. The need for greater awareness of these new technologies by design professionals, building officials, planners, and building owners is discussed, along with the legal constraints to their use, incorporating them into practice, and the undergraduate engineering and architectural curricula.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?,4Anderson, J. C.19908A slip surface isolation system for multistory buildingsEarthquake SpectraVol. 62, pp. 353-369. MaySteel; bearings; Base isolation; dynamic properties; nonlinear response; Hysteresis; Restrainers; Steel frames; Story drift; Displacements (structural); Ductility; steel structures; columns; Shear; Response spectra; Acceleration; Lowrise structures; Multistory structures; Axial loadsThe dynamic response characteristics are investigated of a slip surface isolation system having restraints which produce a bilinear hysteresis. Design issues pertaining to base-isolated structures are reviewed with regard to slip surface systems. The proposed restraint mechanism results in three parameters which can be selected to produce the optional behavior for a given structure.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?-4$Zayas, V. A. Low, S. S. Mahin, S. A.1990;A simple pendulum technique for achieving seismic isolationEarthquake SpectraVol. 62, pp. 317-333. MayFriction pendulum systems; Shaking table tests; isolation; nonlinear response; response; Hysteresis; Story drift; Torsion; Floor response spectra; Base isolation; Multistory frames; Design; Framed structures; Equipment; Uplift; Base shear; Friction; Ground motion; Structural Dynamics The advantages of the friction pendulum system (FPS) are discussed considering the improvements in strength, versatility, and ease of installation as compared to previous systems. Several new inherent performance benefits offered by this system are also discussed, chiefly, use of geometry and gravity to achieve the desired seismic isolation results. This paper summarizes results of a comprehensive research and testing program to assess the technical performance of the FPS. In addition, an example building design is given using the system.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?.4Way, D. Howard, J.1990SSeismic rehabilitation of the Mackay School of Mines: phase III with base isolationEarthquake SpectraVol. 62, pp. 297-308. MayStrengthening; masonry structures; Mackay School of Mines; Univ. of Nevada; Reno; Nevada; Base isolation; nonlinear response; response; Historical structures; Rubber bearings; Time histories; Earthquake-Resistant DesigngThe original Mackay School of Mines Building, constructed mainly of reinforced masonry in 1908, is one of the original buildings of the Univ. of Nevada, and is designated as a national historic monument. Significant structural alterations were made to the original building in 1926 and 1956. Phase III of the work involves adding a library at the basement level and similar functional remodeling. Cost comparison estimates of conventional strengthening and base isolation showed definite advantages in the isolation system since it could filter out most of the damaging forces associated with earthquakes, and thereby eliminate the need to strengthen the unreinforced masonry walls. As a result, many of the original architectural features of the original building can be salvaged. This paper illustrates the base isolation design selected as the seismic retrofit scheme.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 :ri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395AF?'4Benuska, K. L.1990,Loma Prieta earthquake reconnaissance reportEarthquake Spectra!Vol. 6, Suppl, pp. 448 pages. May3Loma Prieta; California earthquake; Oct. 17; 1989; Northern California; earthquake; medical aspects; disaster relief; San Francisco Bay Area; structural damage; urban and regional planning; Industrial plants; damage; California; northern; Lifeline systems; Architectural elements; Accelerograms; earthquakesImmediately following the Oct. 17, 1989, California earthquake, the Earthquake Engineering Research Inst. (EERI), in conjunction with the U.S. National Research Council of the National Academy of Sciences, established a multidisciplinary team of scientists and engineers to coordinate a reconnaissance investigation of the earthquake. The team was divided into eight study topics. The chapters of this report were prepared by each of the task groups of the reconnaissance team. Each group was asked to provide an overview of their observations with particular attention to lessons learned and areas requiring further research. The contents of the reconnaissance report are as follows: 1--Introduction and overview; 2--Geosciences; 3--Ground motion; 4--Geotechnical aspects; 5--Buildings; 6--Bridge structures; 7--Industrial facilities; 8--Lifelines; 9--Architecture, building contents; and building systems; 10--Urban planning; and 11--Socioeconomic impacts and emergency response.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?(4'Mayes, R. L. Jones, L. R. Buckle, I. G.19906Impediments to the implementation of seismic isolationEarthquake SpectraVol. 62, pp. 283-296. MayJapan; base isolation; isolation; New Zealand; United States; Building codes; Socioeconomic aspects; Governmental aspects; Cost analysis; California; Strengthening; Legislation; Research; Earthquake-Resistant DesignfMore than 125 civil engineering structures worldwide have been constructed using the principles of seismic isolation and 15 of these are in the United States. Although use of the technology is increasing in the United States, it is significantly less than that seen in Japan and New Zealand. Some of the impediments that have been encountered, such as design codes, economics, and government leadership, are discussed; and a summary is provided of the status of some of the solutions required for its more widespread use in the United States. A comparison with the Japanese implementation process is also provided.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?)4 Sharpe, R. L.1990?Independent engineer peer review for seismic isolation projectsEarthquake SpectraVol. 62, pp. 309-316. MayyIsolation; engineering peer review; Base isolation; Equipment; Nonstructural elements; Sites; Earthquake-Resistant DesignBecause no standards or codes have yet been developed for the seismic isolation of buildings and their equipment, owners are using independent engineer reviewers to help ensure that the isolation concept is viable for their buildings and that the resulting design and construction meets the agreed upon project needs. Some of the guidelines for peer review are presented, including the responsibilities and scope of review, types of data reviewed, and questions asked by the reviewer.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395[ F?*4Rodwell, E. et al.,1990YEPRI contribution to international utility industry seismic isolation development programEarthquake SpectraVol. 62, pp. 419-430. MayBase isolation; nuclear power plants; dynamic properties; response; Isolation; Rubber bearings; Damping devices; Response spectra; United States; Experimentation; Vertical loads; Bearings; Earthquake-Resistant DesignSeismic isolation was selected as a potential method for increasing the structural integrity margins for liquid metal reactor power plants. Analyses indicated that seismic isolation would reduce by 90 to 95 percent the acceleration experienced by the reactor vessel at its fundamental frequency. A cooperative development program was established by electric utility organizations in Japan, the United Kingdom, and the United States. Alternative seismic isolator concepts were compared and the laminated elastomer/steel with lead plug concept was selected to be the first concept tested. Sixteen half-sized units were tested, and results compared with predictions and potential isolator design improvements inferred. The cooperative program is continuing through testing of other isolator concepts.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23957hF?+4 Kuntz, R. J.1990SEarthquake hazard mitigation: the need for human resources development and researchEarthquake SpectraVol. 62, pp. 265-276. MayCalifornia; base isolation; isolation; structural design; legislation; Design; Education; Humans; Research; Public policy; Earthquake haz < dams; earthquakes; 1971; California; southern; nonlinear response; Los Angeles region; dams; San Fernando Dam; Lower; Seismic safety; embankments; Silts; SandsA reevaluation of the performance of the Lower San Fernando Dam during the Feb. 9, 1971, San Fernando earthquake was conducted to evaluate methods of determining the residual shear strengths of liquefied soils. The use of standard penetration test (SPT) N-value correlations as proposed by H. B. Seed et al. and laboratory tests to obtain steady-state strength as proposed by G. Castro et al. is evaluated. A recommended approach for seismic safety analysis is presented. The approach, which is intended for use by practicing engineers and not for problems of a research nature, generally consists of the techniques developed by Seed et al. and incorporates routine use of a field-performance-based correlation between soil strength and SPT blow counts.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395? F?$4 Kelly, J. M.1990(Base isolation: linear theory and designEarthquake SpectraVol. 62, pp. 223-244. MayBase isolation; analysis; structural design; Rubber bearings; Mode shapes; Two degree-of-freedom systems; Damping; Response spectra; Multistory structures; design; Linear structures; Structural DynamicsGAlthough most of the base isolation systems proposed have been unacceptably complicated, in recent years a few practical systems have been developed and implemented. While some of these systems have been tested on large-scale shaking tables, none have to date been tested as-built by a strong earth tremor. The shaking table testing and related static testing of full-scale components such as isolation bearings, however, has led to a certain degree of acceptance by the profession and it is possible that the number of practical implementations of base isolation will increase quite dramatically in the next few years. This paper describes recent implementations of base isolation and describes an approximate linear theory of isolation which can be used for the design of base isolation systems that use multilayer elastomeric isolators.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?%4Olson, R. A. Lambright, W. H.1990?Base isolation: what we need to know to diffuse this technologyEarthquake SpectraVol. 62, pp. 277-282. May{Base isolation; technology diffusion; Socioeconomic aspects; Design; Earthquakes as Natural Disasters; Governmental AspectsASan Bernardino County's willingness to experiment with a base-isolated building raises broader questions about how engineering innovations are adopted and implemented. Focusing on group decision making, this paper explores the questions that need to be examined if more rapid use of new engineering techniques is desired.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395wDF?&4)Griffith, M. C. Aiken, I. D. Kelly, J. M.1990oComparison of earthquake simulator test results with the SEAONC tentative seismic isolation design requirementsEarthquake SpectraVol. 62, pp. 403-417. MayShaking table tests; base isolation; reinforced concrete shear walls; steel frames; California; Univ. of; at Berkeley; Earthquake Engineering Research Center; structural design criteria; dynamic properties; response; Braced frames; Reinforced concrete shear wall structures; Multistory structures; Multistory frames; Structural Engineers Assn. of Northern California (SEAONC); Rubber bearings; design criteria; Displacements (structural)jEarthquake simulator tests were performed on a one-fifth-scale, six-story reinforced concrete shear wall structure and a one-fourth-scale, nine-story braced steel frame structure. The structures were supported by five different base isolation systems which consisted of various types and combinations of elastomeric bearings. The main objective of this study was to compare the peak experimental displacements of the base isolation systems tested with values given by the tentative base isolation design provisions proposed by the Seismology Committee of the Structural Engineers Assn. of Northern California (SEAONC).Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:ee ' ion on soil properties, measured periods, and recorded ground motions. Based on the detailed study, ATC-3 procedures are used to incorporate soil-structure interaction effects for three additional buildings. The analyses indicate that soil-structure interaction is an important consideration for the stiff shear wall buildings located in Vina del Mar. Reductions in base shear of 10 to 47 percent were computed, but roof drift ratios generally were unchanged. For spectra representing U.S. design ground motions (ATC), reductions in base shear are not expected to be as pronounced and roof drift ratios are expected to increase moderately.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?"4+Ayala, A. G. O'Rourke, M. J. Escobar, J. A.1990kEvaluation of the effects of the 1985 Michoacan earthquake on the water systems in metropolitan Mexico CityEarthquake SpectraVol. 63, pp. 473-496. Aug.Aqueducts; damage; Pipelines; Steel; Seismic risk; Vulnerability; water supply systems; Guerrero-Michoacan; Mexico earthquake; Sept. 19; 1985; Soil-structure interaction; Lifeline systems; Ground motion; geologic conditions; structural damage; Mexico; earthquakes; Mexico CityDuring the Michoacan earthquake of Sept. 19, 1985, the water supply and distribution systems of metropolitan Mexico City were severely damaged. This paper investigates the type of damage, taking into consideration the characteristics of the earthquake and the peculiar soil and topographic conditions of the valley where the city is situated. It describes the water systems in the metropolitan area, the main features of the subsoil conditions, and the engineering aspects of the earthquake, highlighting their relationship to lifeline earthquake engineering. The investigation concentrates on the damage statistics for the buried segmented pipelines in the water systems. It observes and explains the relatively low damage to lifelines in the epicentral region by analyzing and comparing ground motion characteristics there and in Mexico City. Finally, based on the analysis of this information, some recommendations are given to reduce the seismic vulnerability of the water systems in the metropolitan area.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395h##lF?#41Marcuson, W. F., III Hynes, M. E. Franklin, A. G.1990QEvaluation and use of residual strength in seismic safety analysis of embankmentsEarthquake SpectraVol. 63, pp. 529-572. Aug.Soils; dynamic properties; experimental methods; Strength; Southern California; e  directly or peripherally interested in the research, planning, mitigation, and response aspects associated with earthquake-induced injuries and deaths to develop a research agenda for this emerging field. This was achieved by a combination of presentations of summary papers, discussions in small, multidisciplinary working groups, and plenary wrap-up and discussion sessions. This paper presents a condensation and summary of the workshop, its discussions, and its important conclusions.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Paulson, T. J. Abrams, D. P.1990KCorrelation between static and dynamic response of model masonry structuresEarthquake SpectraVol. 63, pp. 573-591. Aug.Concrete; blocks; Reinforced masonry structures; response; Shaking table tests; Static tests; Lateral loads; FINITE; Finite element method; computer applications; Displacements (structural); Strength; Stiffness; Energy absorption; Experimental methods; Structural DynamicsnThis paper presents correlations between response of the same structural system subjected to either dynamic shaking or static lateral forces. Two one-quarter scale test structures were constructed with identical designs and were tested in the laboratory using two different methods. The first structure was subjected to simulated earthquake motions on a shaking table while the second structure was forced to displace through the same history at static rates using computer-controlled servohydraulic actuators. Characteristics of dynamic lateral force distributions are examined first, followed by a description of techniques used for the static loading experiment. Correlations are made between observed response of the statically and dynamically tested twin structures to suggest differences in strength, stiffness, and energy dissipation that may arise with each test method.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Aktan, A. E. Ho, I. K.19906Seismic vulnerability evaluation of existing buildingsEarthquake SpectraVol. 63, pp. 439-472. Aug.qApplied Technology Council; ATC-14; Reinforced concrete structures; evaluation; United States; U.S. Federal Emergency Management Agency; structural design criteria; Japan; Cincinnati; Univ. of; Ohio; Central United States; Midwestern United States; Foundations; soil-foundation-structure interaction; Soil-structure interaction; Tall buildings; Seismic risk; structures[A study of building seismic vulnerability evaluation methods in the U.S. and Japan led to a constructive critique of the FEMA-178. Research is formulated to extend FEMA-178 so that types of construction which have not yet experienced damaging earthquakes may be reliably evaluated. An element-level analytical model accurately simulating the critical response and failure mechanisms of the soil-foundation-structure in its current state emerges as a key. Developing such a model may prove difficult in case a facility has unusual and/or irregular attributes as well as damage and/or deterioration. Researchers' efforts to construct and experimentally identify a three-dimensional analytical model of a 27-story reinforced concrete flat-plate building with closed thin-walled core systems are described. Forced-excitation modal testing is explored and is shown to be a reliable tool. It is exemplified that structural identification as well as other nondestructive evaluation tools may become essential for reliably evaluating seismic vulnerability of construction which has not yet revealed all of its "weak links."Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23959F? 4Jones, B. G. Lewis, B. D.1990OEstimating size distributions of building areas for natural hazards assessmentsEarthquake SpectraVol. 63, pp. 497-505. Aug.Wichita; Kansas; structural size; Central United States; New York City; California; Structures; size; floor areas; Seismic risk; Western United States; Eastern United States; Vulnerability; Disaster planning; Earthquake-Resistant DesignIt is very helpful to be able to estimate the number of buildings in floor area size categories for various purposes in risk assessment, vulnerability reduction, emergency response, recovery, and reconstruction planning. This paper compiles a frequency distribution by floor area from a data set for 900,000 buildings, using complete enumerations of buildings from several urban areas. Three models are fit to the data: the lognormal distribution and two regression models based on the negative exponential. A regression model estimating the percentage of buildings larger than a given size provides the best fit and is a useful technique for making predictions. Since estimates produced by regression techniques have known error distributions, the results will only be approximate. For places for which the building stock has considerably different characteristics from the data set, the parameters of the model will have to be recalculated. An actual example of application of the model is presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395B8F?!4Wallace, J. W. Moehle, J. P.1990oEvaluation of ATC requirements for soil-structure interaction using data from the 3 March 1985 Chile earthquakeEarthquake SpectraVol. 63, pp. 593-611. Aug.Roofs; drift; Chile; earthquakes; 1985; Vina del Mar; Shear wall structures; response; Applied Technology Council; ATC 3-06; United States; structural design criteria; Base shear; soil-structure interaction; Earthquake-Resistant DesignThe effect of soil-structure interaction on building responses during the earthquake is investigated for four shear wall buildings located in Vina del Mar, Chile. The buildings were subjected to strong, long duration earthquake ground motions during the earthquake. Detailed analyses are conducted on one building using available informat  averaged from 0.5 to 1.0 units less than intensities within other areas over comparable distances. Simulated ground acceleration time histories were generated along two profiles: one trending northeast from the epicenter along the coast and another trending northwest toward the fall line.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Kawashima, K. Kanoh, T.1990\Evaluation of indirect economic effects caused by the 1983 Nihonkai-chubu, Japan, earthquakeEarthquake SpectraVol. 64, pp. 739-756. Nov.Nihonkai-chubu; Japan earthquake; May 26; 1983; economic analysis; Japan; earthquakes; Mathematical models; Transportation systems; production loss; Reconstruction; Businesses; Industrial plants; Damage; Earthquakes as Natural DisasterspThis paper presents a method for estimating indirect economic effects caused by an earthquake. Loss of production caused by damage to production facilities, transportation facilities, materials, and goods, as well as the effects of investment for restoration, are considered. Based on direct loss associated with production loss, a secondary ripple effect is estimated through an inter-industry relation analysis (input-output analysis). The procedure is applied to the Nihonkai-chubu, Japan, earthquake of 1983. Gross product estimations are compared with those actually observed after the earthquake in the damaged region.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4 Mittler, E.1990=Evaluating alternative national earthquake insurance programsEarthquake SpectraVol. 64, pp. 757-778. Nov.Insurance; history; legislation; United States; national earthquake insurance programs; Public policy; Earthquakes as Natural Disasters; Governmental Aspects?In April 1990, two bills to create a national earthquake insurance program were introduced in the United States Congress. The content and scope of these bills are analyzed and compared, taking into account the results of over 25 years of investigations concerning what role the federal government should have in a national program. Both bills are still under review by committee. Progress is being made toward adoption of a national program. A critical determinant will be if Congress can first determine and then agree to an acceptable link between insurance and mitigation.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 o0F?4Jones, N. P. et al.,19909Considerations in the epidemiology of earthquake injuriesEarthquake SpectraVol. 63, pp. 507-528. Aug.Humans; injuries; casualties; Disaster planning; Socioeconomic aspects; Experimentation; structures and humans; Disaster relief; Structures; Earthquake Injury Epidemiology for Mitigation and Response; Workshop; 1989; Conference ProceedingsIn July 1989, a workshop entitled "Earthquake Injury Epidemiology for Mitigation and Response" was held at the Johns Hopkins Univ. in Baltimore, Maryland. The aim of the workshop was to gather a group of interested professio  ilding and earthquake is approximately represented by proposed building code provisions for soil-structure interaction.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Jongmans, D. Campillo, M.1990?The 1983 Liege earthquake: damage distribution and site effectsEarthquake SpectraVol. 64, pp. 713-737. Nov.Belgium; earthquakes; 1983; Liege; earthquake; Nov. 8; Geologic conditions; structural damage; ground motion; Amplification; Northwestern Europe; Masonry structures; damage; Chimneys; Houses; Walls; Roofs; Alluvium; BedrockOn Nov. 8, 1983, a moderate magnitude (ML = 4.9) earthquake struck Liege, Belgium. A damage study showed that site effects at different scales played an important role in amplifying ground motion. On a large scale, the damage distribution was determined by the presence of a large carboniferous syncline beneath the city as shown by two-dimensional numerical modeling. On a small scale, the main damage concentrations can be correlated with local superficial deposits which have amplified ground motions in the frequency range of buildings. A geophysical survey was carried out to measure the shear wave velocity of the different formations. Site response computations were made at numerous sites in order to estimate the possible amplification and to compare the results with the damage. Spectral amplifications computed in the dominant frequency range of the buildings were compared with the damage data. In very affected areas, one-dimensional amplifications of four to six were obtained; and, in some cases, two-dimensional effects may have occurred. The Liege earthquake, taking place in the intraplate region of northwestern Europe, is significant in the study of other similar areas, such as the eastern United States.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395!W9xF?4Chapman, M. C. et al.,1990The influence of the Coastal Plain sedimentary wedge on strong ground motions from the 1886 Charleston, South Carolina, earthquakeEarthquake SpectraVol. 64, pp. 617-640. Nov.South Carolina; earthquake; 1886; ground motion; Charleston; Geologic conditions; United States; southeastern; simulation; Earthquake intensities; Southeastern United States; Acceleration; Georgia; North Carolina; seismograms; Engineering SeismologyThe effect of Atlantic Coastal Plain sediments on ground motion from the 1886 Charleston, South Carolina, earthquake was studied using linear regression analysis and ground motion modeling. Statistical tests applied to 264 modified Mercalli intensity reports at epicentral distances less than 400 km showed that intensities within the lower Coastal Plain (near the coast) m or absent, but where young fault scarps attest to recent or ongoing tectonism. Three non-Poisson models, a Weibull model, a Gaussian model, and a lognormal model, are used to estimate the earthquake hazard for one such area, the northern Rio Grande Rift. This portion of the Rio Grande Rift displays numerous Holocene faults attesting to ongoing tectonism, but displays essentially no historical seismicity. The earthquake hazard for the Sangre de Cristo fault zone from Taos, New Mexico, to Salida, Colorado, calculated using these models is remarkably consistent with increased hazard for the Sangre de Cristo fault in north San Luis Valley and near Taos due to the long holding times along these segments.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395/F?4Fenves, G. L. Serino, G.1990?Soil-structure interaction in buildings from earthquake recordsEarthquake SpectraVol. 64, pp. 641-655. Nov.nReinforced concrete structures; response; soil-structure interaction; dynamic properties; Mathematical models; Foundation-structure interaction; Base shear; Los Angeles; Southern California; earthquakes; 1987; Warehouses; Multistory structures; Whittier Narrows; California earthquake; Oct. 1; Foundations; soil-foundation-structure interaction; Substructure methods(An evaluation of the response of a 14-story reinforced concrete building to the Oct. 1, 1987, Whittier Narrows, California, earthquake and Oct. 4, 1987, aftershock shows significant effects of soil-structure interaction. A mathematical model of the building-foundation-soil system provides response quantities not directly available from the records. The model is calibrated using the dynamic properties of the building as determined from the processed strong-motion records. Soil-structure interaction reduces the base shear force in the longitudinal direction of the building compared with the typical assumption in which interaction is neglected. The reduction in base ia; northern; Governmental aspects; Highway bridges; San Francisco-Oakland Bay Bridge; Cypress Street Viaduct; Oakland; Embarcadero Freeway; San FranciscoA board of inquiry was appointed by the Governor of California to investigate the 1989 Loma Prieta, California, earthquake. The formation of the board was prompted by earthquake damage to bridges and freeway structures and the desire to know not only what happened, but how to prevent such destruction in future earthquakes. The board made 52 specific findings and eight recommendations. They identified three essential challenges: (1) ensure that earthquake risks posed by new construction are acceptable; (2) identify and correct unacceptable seismic safety conditions in existing structures; and (3) develop and implement actions that foster the rapid, effective, and economic response to and recovery from damaging earthquakes. An Executive Order implementing the principal recommendations of the board establishes the policy that all state-owned and operated structures are to be seismically safe and that important structures are to maintain their function after earthquakes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Ozkan, Y. et al.,1990CDamage at Surgu Dam during May 5, 1986, Malatya, Turkey, earthquakeEarthquake SpectraVol. 64, pp. 779-796. Nov.Turkey; rockfill dams; earthquakes; 1986; damage; dynamic properties; Anatolia; dams; Seismicity; Stability; Maps; Anatolian fault; Rural structures; Ambient vibrations; Slopes; analysis; Ground motion; Earthquake Damage\On May 5, 1986, an earthquake of approximately M = 6 struck South Anatolia, Turkey, creating widespread damage of rural structures and causing extensive longitudinal cracks at the crest of Surgu Dam. This paper gives general information about the earthquake and presents the results of block-mass and circular arch types of pseudo-static slope stability analyses. Probabilistic findings based upon seismicity observed in the last century indicate that substantially higher levels of ground shaking may occur at the dam site. Such occurrences are considered capable of causing hazardous damage to the dam.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Rihn, W. J. et al.,19906Analysis and testing of the FBA-11 force accelerometerEarthquake SpectraVol. 64, pp. 797-809. Nov.|Accelerometers; dynamic properties; Acceleration; instruments; Ground motion; Shaking table tests; Strong Motion SeismometryBThe FBA-11 is a feedback-controlled accelerometer widely used to measure and record accelerations arising from earthquakes. It has found application both for structural response and for ground motion studies. The FBA-11 is designed to provide electronic control of natural frequency, damping, and output voltage. Included in this paper are (1) a circuit analysis yielding the complete closed-loop transfer function and (2) the corroborative test results from shaking table evaluations. The transfer function can be used to correct recorded accelerations for instrument response.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23957R|F?4 Glass, C. E.1990Earthquake hazard estimation in areas of low historical seismicity: a focus on the northern Rio Grande Rift, Colorado and New MexicoEarthquake SpectraVol. 64, pp. 657-680. Nov.Rio Grande rift; Southwestern United States; faults; Earthquake hazards; United States; southwestern; New Mexico; seismic risk; Colorado; Sangre de Cristo fault zone; Taos; Seismicity; Seismology; Earthquake RiskEEstimates of the probability of future earthquake activity are difficult to make in areas where historical seismicity may be low  ffects of these reductions on potential damage to tanks. Some type of nonlinear analysis is needed to assess the tank's desired performance objectives. This paper presents a simplified nonlinear analysis for performance-based seismic design of tanks. It also presents a method of strengthening tanks by energy-dissipating base anchors. The simplified nonlinear analysis is illustrated for an unanchored tank, a tank anchored with traditional anchors, and a tank anchored with energy-dissipating anchors.# F?2Hall, John F. Ryan, Keri L.20007Isolated buildings and the 1997 UBC near-source factorsEarthquake SpectraVol. 162, pp. 393-411. MayUniform Building Code (UBC); 1997 edition; United States; building codes; Base isolation; near-field ground motion; Rubber bearings; nonlinear response; Multistory moment-resisting frames; story drift; Northridge; California earthquake; Jan. 17;Computer simulations are employed to assess the effects of near-source ground motions on base-isolated buildings that meet the provisions of the 1997 Uniform Building Code. A six-story base-isolated building designed for N subscript V = 1.6 exhibits essentially elastic structural behavior when subjected to six actual ground motions containing strong near-source effects. However, two simulated records, one intended to represent the most severe motions from the 1994 Northridge earthquake and the other a strong motion from a hypothetical M subscript w 7.0 thrust earthquake, produce larger responses well into the nonlinear range. In addition, a 113 cm ground displacement pulse of three-second duration, which is close to the period of the isolated buildings, causes story drifts of nearly 5% for the N subscript V = 1.6 design and over 2% for a stronger N subscript V = 2 design. Such drifts are effectively reduced when supplemental dampers are added alongside the isolators. The original N subscript V = 1.6 design with supplemental damping in the amount of 20% of critical experiences only 1.3% drift for the same three-second ground displacement pulse.F?2.Azevedo, Joao Sincraian, Gabriela Lemos, J. V.2000-Seismic behavior of blocky masonry structuresEarthquake SpectraVol. 162, pp. 337-365. MayUnreinforced masonry bell towers; strengthening; Unreinforced masonry block structures; nonlinear analysis; Unreinforced stone structures; cracking; Europe; historical structures; San Giorgio in Trignano Church bell tower; San Martino; Rio; Italy; Lisbon; Portugal; aqueductsThe seismic behavior of structures composed of masonry blocks is analyzed using the discrete element method. Some features of the method are described, including the representation of the block deformation, contacts, and block interaction. The suitability of the method for the analysis of masonry structures is examined. The seismic behavior of simple structural systems as well as that of real structures is studied. It is shown that the method is able to reproduce important phenomena, such as crack opening and joint sliding, which are responsible for the occurrence of structural damage and collapse. The collapse patterns of the analyzed structures are examined, reinforcing schemes using steel cables are considered, and seismic vulnerability functions are obtained.F?2Jangid, R. S. Kelly, J. M.20002Torsional displacements in base-isolated buildingsEarthquake SpectraVol. 162, pp. 443-454. MayBase isolation; torsion; Uniform Building Code (UBC); 1997 edition; United States; building codes; Bearings; displacements (structural); Rigid decks; response spectrum analysis; Northridge; California earthquake; Jan. 17;An analytical study of the effects of torsional coupling on the seismic response of a base-isolated building is presented. The isolated structure is modeled as a rigid deck supported on axially inextensible bearings. The governing equations of motion for the coupled lateral-torsional response of the system are derived. The eccentricity in the system is that specified by the Uniform Building Code (UBC). The displacement response of the isolated system with different combinations of building configuration, isolation damping, and the ratio of uncoupled torsional to lateral frequency of the system is investigated. The response of the isolated structure under a variety of near-fault and other earthquake ground motions is compared to that obtained by use of response spectrum analysis. In the response spectrum analysis, the accuracy of several modal combination rules is evaluated. It is shown that torsional coupling can influence the response of the isolated structure; but if the layout of the isolation bearings is such that the torsional frequency is larger than the lateral frequency, the effect is reduced and the usual modal combination rules work well. It is also shown that, in this case, the UBC static formula for the additional isolator displacements due to torsion is conservative.ZF?2Kumar, Sanjeev2000SEvaluation and reduction of liquefaction potential at a site in St. Louis, MissouriEarthquake SpectraVol. 162, pp. 455-472. MayRiverport area; St. Louis; Missouri; liquefaction prediction; Central United States; multistory office buildings; Soil densification; Soil improvement; Ground motion; amplificationThis paper presents results of seismic ground response and liquefaction analyses performed for a site located in the floodplain of the Missouri River in St. Louis, Missouri. Synthetic earthquake time histories and recorded ground motions from two earthquakes in Canada were used to perform the analyses. Synthetic time histories were generated using attenuation relationships for the Central United States. The ground response analyses indicated that the ground motions at the site are likely to amplify by a factor between 1.4 and 2.25. From the liquefaction analysis, it was concluded that the site had significant liquefaction potential. The site was remediated to reduce liquefaction potential using deep dynamic compaction. Modifications, in the form of construction of stone columns, were made to the conventional method of deep dynamic compaction to densify the soils to required depths. Results presented show that the site remediation procedure used at the site successfully densified the site soils to desired densities. Construction of stone columns not only densified the in-place soils to deeper depths, but also helped to support relatively heavily loaded columns on spread footings. The project was completed on schedule with significant cost savings.F?2Stewart, Jonathan P.2000LVariations between foundation-level and free-field earthquake ground motionsEarthquake SpectraVol. 162, pp. 511-532. MayNorthern California; strong-motion instrument arrays; San Francisco Bay Area; Southern California; Los Angeles region; site effects; Los Angeles; Ground motion; foundation-level and free-field; Soils; nonlinear response; Soil-structure interactionrStrong motion data from sites having both an instrumented structure and a free-field accelerograph are compiled to evaluate the conditions for which foundation recordings provide a reasonably unbiased estimate of free-field motion with minimal uncertainty. Variations between foundation and free-field spectral acceleration are found to correlate well with dimensionless parameters that strongly influence kinematic and inertial soil-structure interaction phenomena such as embedment ratio, dimensionless frequency (i.e., product of radial frequency and foundation radius normalized by soil shear wave velocity), and ratio of structure-to-soil stiffness. Low frequency components of spectral acceleration recorded on shallowly embedded foundations are found to provide good estimates of free-field motion. In contrast, foundation-level peak ground acceleration (both horizontal and vertical) and maximum horizontal velocity are found to be de-amplified. Implications for ground motion selection procedures employed in attenuation relations are discussed, and specific recommendations are made as to how these procedures could be improved.F?2Aschheim, Mark Black, Edgar F.20009Yield point spectra for seismic design and rehabilitationEarthquake SpectraVol. 162, pp. 317-335. MayYield point spectra; performance-based design; Multistory structures; nonlinear static analysis; Ground motion; United States; U.S. Federal Emergency Management Agency (FEMA) FEMA 273/274aA new spectral representation of seismic demand is described for use in the seismic design of new structures and in the evaluation and rehabilitation of existing structures. Yield point spectra (YPS) retain the intuitive appeal of the capacity spectrum method and join the nonlinear static procedures of FEMA 273/274 and ATC 40 for use in estimating displacement demands. YPS also may be used to establish admissible combinations of strength and stiffness for the design of new structures to limit system ductility and drift to arbitrary values. Graphical procedures allow admissible design regions to be established to satisfy multiple performance objectives. YPS computed for 15 ground motions classified as short duration, long duration, or as containing near-fault forward directivity pulses are presented for bilinear and stiffness-degrading hysteretic models.F?2Yashinsky, Mark Ostrom, Thomas20001Caltrans' new Seismic Design Criteria for bridgesEarthquake SpectraVol. 161, pp. 285-307. Feb.California; California Dept. of Transportation (Caltrans); Bridges; design criteria; Highway bridges; performance-based design; DuctilityCaltrans' Seismic Design Criteria (SDC) has been adopted as the minimum seismic standard for ordinary bridges on California's highways. The SDC is a compilation of new and existing seismic criteria that had been previously documented in a variety of Caltrans documents. The SDC extends the capacity design philosophy introduced in the 1980 Caltrans Bridge Design Specifications. The most significant departure from the previous procedure is that ductile members are now designed by comparing the displacement demand to the displacement capacity. The demands are generated by a linear elastic analysis, and the capacities are determined from a curvature analysis that incorporates the nonlinear behavior of the structural elements. The demand/capacity methodology supplants the previous method based on reducing the elastic dynamic forces by a force reduction factor. In this paper, the significant features of Caltrans' SDC are described. F?2Petersen, Mark D. et al.,2000nActive fault near-source zones within and bordering the state of California for the 1997 Uniform Building CodeEarthquake SpectraVol. 161, pp. 69-83. Feb.XUniform Building Code (UBC); 1997 edition; United States; building codes; California; active fault near-source zone maps; Nevada; Near-field ground motion; Southern California; faults; Northern California; Central California; Eastern California; San Andreas fault; Earthquake hazard maps; Near-source coefficients; Lancaster; Los Angeles CountybThe fault sources in the Project 97 probabilistic seismic hazard maps for the state of California were used to construct maps for defining near-source seismic coefficients, N subscript a and N subscript v, incorporated in the 1997 Uniform Building Code (ICBO 1997). The near-source factors are based on the distance from a known active fault that is classified as either Type A or Type B. To determine the near-source factor, four pieces of geologic information are required: (1) recognizing a fault and determining whether or not the fault has been active during the Holocene, (2) identifying the location of the fault at or beneath the ground surface, (3) estimating the slip rate of the fault, and (4) estimating the maximum earthquake magnitude for each fault segment. This paper describes the information used to produce the fault classifications and distances. F?2Leyendecker, Edgar V. et al.,2000?Development of maximum considered earthquake ground motion mapsEarthquake SpectraVol. 161, pp. 21-40. Feb.United States; U.S. Natl. Earthquake Hazards Reduction Program (NEHRP) 1997 Recommended Provisions; building codes; Design criteria; Spectral response acceleration; Ground motion maps; maximum considered earthquakes; Los Angeles; earthquake hazard analysis; Southern California; San Francisco; uniform hazard spectra; Northern California; Western United States; Seattle; Washington; Pacific Northwest; Salt Lake City; UtahThe 1997 NEHRP Recommended Provisions for Seismic Regulations for New Buildings use a design procedure that is based on spectral response acceleration rather than the traditional peak ground acceleration, peak ground velocity, or zone factors. The spectral response accelerations are obtained from maps prepared following the recommendations of the Building Seismic Safety Council's (BSSC) Seismic Design Procedures Group (SDPG). The SDPG-recommended maps, the Maximum Considered Earthquake (MCE) Ground Motion Maps, are based on the U.S. Geological Survey (USGS) probabilistic hazard maps with additional modifications incorporating deterministic ground motions in selected areas and the application of engineering judgment. The MCE ground motion maps included with the 1997 NEHRP Provisions also serve as the basis for the ground motion maps used in the seismic design portions of the 2000 International Building Code and the 2000 International Residential Code. Additionally, the design maps prepared for the 1997 NEHRP Provisions, combined with selected USGS probabilistic maps, are used with the 1997 NEHRP Guidelines for the Seismic Rehabilitation of Buildings.F?2$Drake, Richard M. Bragagnolo, Leo J.2000ZModel code design force provisions for elements of structures and nonstructural componentsEarthquake SpectraVol. 161, pp. 115-125. Feb.~United States; U.S. Natl. Earthquake Hazards Reduction Program (NEHRP) 1997 Recommended Provisions; Design criteria; Uniform Building Code (UBC); 1994 edition; 1997 edition; Building codes; Nonstructural elements; Charleston; South Carolina; suspended ceilings; St. Louis; Missouri; parapets; San Francisco; exterior walls; Northern California; structural design and soil conditions`With the publication of the 1997 Uniform Building Code (UBC) and the 1997 NEHRP Recommended Provisions for the Seismic Regulations for New Buildings and Other Structures, there has been a significant change in the earthquake design force provisions for buildings, structures, elements of structures and nonstructural components. Engineers and architects need to become informed regarding a variety of earthquake design force provisions, primarily those published in the UBC and those developed as part of the NEHRP Provisions. Both sources provide design force provisions for the building structural system and separate design force provisions for elements of structures and nonstructural components. This paper describes the development, evolution, and application of the earthquake design force provisions for elements of structures and nonstructural components.I{F?2 Ghosh, S. K.2000CMajor changes in concrete-related provisions -- 1997 UBC and beyondEarthquake SpectraVol. 161, pp. 141-162. Feb.Uniform Building Code (UBC); 1994 edition; 1997 edition; United States; U.S. Natl. Earthquake Hazards Reduction Program (NEHRP) 1997 Recommended Provisions; U.S. Natl. Earthquake Hazards Reduction Program (NEHRP) 1994 Recommended Provisions; Reinforced concrete structures; building codes; Reinforced concrete shear walls; Precast concrete structures; design criteria; International Building Code (IBC) 2000; American Concrete Inst. (ACI); ACI 318-99U.S. seismic codes are undergoing profound changes as of this writing. Changes from the 1994 to the 1997 edition of the Uniform Building Code (UBC) (ICBO 1994, 1997) are many and far-reaching in their impact. The 1997 edition of the National Earthquake Hazards Reduction Program (NEHRP) Recommended Provisions for Seismic Regulations for New Buildings (BSSC 1998) contains further evolutionary changes in seismic design requirements beyond those of the 1997 UBC. The latter document will form the basis of the seismic design provisions of the first edition of the International Building Code (IBC), to be published in the spring of 2000. This paper first discusses the major changes that have been made in the concrete-related provisions from the 1994 to the 1997 edition of the UBC. The paper gives background to these changes, provides essential details on them, and indicates how they have been or how they are going to be incorporated (at times with significant modifications) into the 1997 NEHRP Provisions and the 2000 IBC. The newly published ACI 318-99, Building Code Requirements for Structural Concrete (ACI 1999), is going to be adopted by reference into the 2000 IBC. This entails further changes in concrete-related provisions beyond the 1997 UBC. Some of the more important of these chang ZPrieta earthquakeEarthquake SpectraVol. 64, pp. 681-711. Nov.&Loma Prieta; California earthquake; Oct. 17; 1989; transportation systems; Northern California; earthquake; bridges; usage; damage; Californ G in engineering analyses are derived from these data. The derived coherency functions are applicable to all frequencies and to separation distances up to 100 m.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395EF?4 Kreimer, A.1991@Reconstruction after earthquakes: sustainability and developmentEarthquake SpectraVol. 71, pp. 97-106. Feb.Reconstruction; Disaster relief; Land use; Urban and regional planning; Vulnerability; Seismic risk; Disaster planning; Earthquakes as Natural DisastershThis paper identifies key sustainability issues arising in earthquake-related projects financed by the World Bank. First, bank-financed reconstruction activities are briefly described within the background of the bank's objectives in development. Discussed next are the connections between human activities and development decisions on the one hand and seismic risk and vulnerability on the other. The multiple nature of earthquake-related losses are identified, including economic (direct and indirect), time-related, and institutional losses. Third, resource mobilization efforts following disasters are discussed, including issues related to local and international aid. Fourth, the inclusion of measures geared to preventing losses in bank-financed reconstruction efforts are explored within the overall context of preserving sustainability and reducing vulnerability.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395`F?4Yaghoubian, J.1991AIsolating building contents from earthquake induced floor motionsEarthquake SpectraVol. 71, pp. 127-143. Feb.Base isolation; Art objects; Getty; J. Paul; Museum; California; Southern California; museums; Shaking table tests; Nonstructural elements; Earthquake-Resistant DesignoThe single isolation unit described in this paper has been extensively tested during shake table test programs. The isolation system operates at about critical damping and can accommodate a large variety of random dynamic motions generated by earthquakes. The system is flexible and can be customized for different configurations and specific functional performances.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Englekirk, R. E. Sabol, T. A.19912Strengthening buildings to a life safety criterionEarthquake SpectraVol. 71, pp. 81-87. Feb.qStrengthening; humans; structural strengthening; Concrete structures; Seismic safety; Earthquake-Resistant DesignExisting buildings do not comply with most provisions of modern model building codes and, as a result, are often considered seismically deficient. This paper presents an approach to seismically strengthen buildings to a life- safety criterion.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395k F?4Anderson, J. G. Brune, J. N.1991AThe Victoria accelerogram for the 1980 Mexicali Valley earthquakeEarthquake SpectraVol. 71, pp. 29-43. Feb.Mexicali Valley; Mexico; earthquakes; 1980; Accelerograms; Mexico earthquakes; Imperial Valley; California; Acceleration; Engineering SeismologyIn the preliminary analysis of records obtained from the June 9, 1980, MW 6.4 Mexicali Valley, Mexico, earthquake, significant portions of the digital magnetic records were not decoded due to a low magnetization level. This paper presents the final data for the Victoria accelerogram recorded during this earthquake, recovered by careful analysis, and discusses its importance and that of other recent strong-motion data and research. Peak horizontal accelerations (.98 g, .87 g) and duration are compared to the values for the 1987 Superstition Hills, California, earthquake. The vertical accelerogram clipped the 1 g instrument several times. The records provide an important example of near-fault accelerations from a second earthquake in the deep sediments of the Imperial- Mexicali Valley (the other being the records from the 1979 Imperial Valley earthquake). The 1980 accelerograms are important because they were not affected by foundation filtering, as were the records for the Imperial Valley 1940 earthquake, and because they illustrate the damaging near-source, intermediate frequency velocity pulse associated with passage of the rupture front.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395zF?4 Housner, G. W. Thiel, C. C., Jr.1990dCompeting against time: report of the Governor's Board of Inquiry on the 1989 Loma focal mechanisms.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Brune, J. N. Anooshehpoor, A.1991BFoam rubber modeling of the El Centro terminal substation buildingEarthquake SpectraVol. 71, pp. 45-79. Feb.Physical models; soil-structure interaction; El Centro; California; earthquakes; 1940; Southern California; Foundations; Experimentation; Structural DynamicsThe El Centro Terminal Substation building, the site of the accelerograph which recorded the May 1940 El Centro earthquake, has a massive foundation and rests on soft soil deposits. Under these conditions, strong soil- structure interaction effects are likely to cause the acceleration recorded in the building to differ from the true free-field ground motion. A 1980 study using two- dimensional numerical modeling, concluded that at frequencies above 1.5 Hz, the motions in the building fall significantly below the free-field ground motions. In this paper, a study using three-dimensional foam rubber modeling is described. A homogeneous block of foam rubber (polyurethane) representing the soil and buildings made of styrofoam are used for comparison with analytical solutions. These simple structures consist of rigid cylindrical foundations on a uniform halfspace. Different size structures (all cylindrical), both embedded and attached flat to the surface, were used. To get the free- field ground motions, vertically incident SH-waves were recorded on the uncut surface of the foam block in the absence of any structure. Then the structure was bonded (flat or embedded) to the foam rubber block and displacements measured at points of interest on the structure subject to the same shear wave as in the free- field case. Theoretical results are compared with the experimental results for 12 different cylindrical structures attached flat to the surface of the foam.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395#QF?4/Abrahamson, N. A. Schneider, J. F. Stepp, J. C.1991\Empirical spatial coherency functions for application to soil-structure interaction analysesEarthquake SpectraVol. 71, pp. 1-27. Feb.eGround motion; spatial variation; soil-structure interaction; S-waves; Taiwan; Engineering Seismology;The spatial coherency of strong ground motion from 15 earthquakes recorded by the Lotung (Taiwan) Large-Scale Seismic Test strong-motion array is analyzed. The earthquakes range from 3.7 to 7.8 and from 5 to 80 km in epicentral distance. A total of 533 station pairs are used with station separations ranging from 6 to 85 m. Empirical coherency functions for the horizontal component S-waves appropriate y99 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395OìF? 4'Vidale, J. E. Bonamassa, O. Houston, H.1991Directional site resonances observed from the 1 October 1987 Whittier Narrows, California, earthquake and the 4 October aftershockEarthquake SpectraVol. 71, pp. 107-125. Feb.Whittier Narrows; California earthquake; Oct. 1; 1987; ground motion; Southern California; earthquakes; geologic conditions; directional resonance; Sites; S-waves; California; southern; Engineering SeismologyThe frequency content and polarization characteristics are analyzed of the Oct. 1, 1987, Whittier Narrows (California) main shock and aftershock to understand the relative contributions of source and site to observed ground motions. The sequence had very different focal mechanisms, but at 8 of 11 strong-motion stations for which digitized records of both events are available, the direction of strongest shaking in the two events was much more similar than would be expected. To assess the prevalence of frequency and direction-dependent site resonances, the particle motions of S-waves are compared with those predicted from the earthquake  ct. 1, 1987. Roughly 33 percent of the California Div. of Mines and Geology stations located between 75 and 110 km from the epicenter did not trigger at the 1 percent g vertical acceleration level. No stations triggered beyond 115 km from the epicenter. A standard parametric form is fit to the vertical peak acceleration data using both least squares estimation and maximum likelihood estimation methods. The inclusion of censoring data is evaluated for effects on the regression of attenuation parameters and for a comparison of the maximum likelihood estimation and least squares estimation solution.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395,hF? 4 Gori, P. L.1991_Communication between scientists and practitioners: the important link in knowledge utilizationEarthquake SpectraVol. 71, pp. 89-95. Feb.BEarthquake engineering; Research; Earthquakes as Natural DisastersPersonal interaction between investigators doing research and potential users of results of research is essential for the incorporation of new information into policy and practice. Interactive workshops, advisory committees, interdisciplinary research projects, and professional societies are some of the arenas where this interaction takes place. The author describes research into how knowledge is used. Of particular interest is a study which scrutinized the natural hazards field.Earthquake Engineering Research Ins 0rced concrete; hospitals; Mexicali; Mexico; Baja California; Soil-structure interaction; dynamic properties; Structural DynamicsThis paper describes the results of ambient vibration tests of the eight-story reinforced-concrete hospitalization tower of the Mexicali General Hospital. The structure suffered some damage during the November 1987 Superstition Hills, California, earthquakes. The tests were conducted in April and August 1989 before and after major alterations of the building were made. The frequencies, modal damping ratios, and mode shapes of some of the longitudinal, transverse, and torsional modes were determined for the April and August 1989 conditions. The results consider the effects of removing the facade of the building on the longitudinal stiffness of the structure and the effects of soil-structure interaction on the transverse and longitudinal response of this structure.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F? 4McLaughlin, K. L.1991HMaximum likelihood estimation of strong-motion attenuation relationshipsEarthquake SpectraVol. 72, pp. 267-279. MayAttenuation; ground motion; analysis; maximum likelihood estimation; Acceleration; Whittier Narrows; California earthquake; Oct. 1; 1987; Southern California; earthquakes; Engineering SeismologyAn example is shown for peak acceleration data recorded from the Whittier Narrows, California, earthquake of O nrectly applicable to industrial facilities in other seismic regions of the world, including the United States.`F?a2 Gulkan, Polat2000Kocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 15 -- building code enforcement prospects: the failure of public policyEarthquake Spectra$Vol. 16, Suppl. A, pp. 351-374. Dec.Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; governmental aspects; Duzce; Nov. 12; Turkey; building codes; Design; Public policy; Construction; liabilityThe two recent major earthquakes in Turkey on August 17 and November 12, 1999, both occurred in or near urban settlements and caused widespread destruction of the building stock. Several factors contributed to this destruction. First, it was "discovered" that densely populated conurbations were transversed by major active faults, with no preventive measures put into effect during the plan stage against possible effects. Nearly all building collapses occurred within a 5-km-wide slice of land on either side of the fault trace. Second, even in cities removed from the fault trace, the building stock displayed widespread endemic weaknesses that led to collapses and intolerable loss of life. The urbanization in the Marmara Sea region has occurred largely during the past quarter century. Critical evaluation of the 1975 seismic code for its near-field performance is necessary to answer the question, Even if the code had been enforced, would it have served to save lives? This chapter offers a comparison between some of its requirements and those contained in the current, 1998, code. First, the countrywide earthquake resistant design provisions from the time of their inception will be examined, evaluating their adequacy in view of current thinking. Next, code enforcement policies at the local government level will be examined. This discussion explains not what happened, but why it happened. References are made to faulty design practices that are common in Turkey. F?b2O'Rourke, T. D. et al.,2000Kocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 16 -- water, gas, electric power, and telecommunications performanceEarthquake Spectra$Vol. 16, Suppl. A, pp. 377-402. Dec.Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; lifeline systems; Adapazari; Turkey; water supply systems; Izmit Water Project; Gas supply systems; damage; Electric power distribution; Telecommunications systemsThe August 17, 1999, Kocaeli earthquake caused significant disruption of lifeline systems. The most pervasive damage to water supply lifelines occurred in Adapazari, primarily because soil liquefaction and ground softening led to significant differential soil movements that disengaged and fractured the brittle asbestos cement pipelines that were deployed throughout the city. There was an immediate, countrywide blackout of the electric power transmission system due to high-voltage substation damage and power plants tripping off. Significant distribution system damage occurred in seven provinces that consume more than 40% of all electric power used in the country. Despite the initial power outage and the primarily local difficulties, the overall performance of lifeline systems was reasonably good. Water in the areas of strongest shaking was supplied by three regional agencies, all operating modern water treatment plants in conjunction with modern reservoirs impounded by earth fill and concrete dams. There was only minor damage at the treatment plants, which was rapidly repaired. Likewise, damage was either negligible or minor at the main dam and reservoir facilities. The natural gas distribution system in Izmit, primarily modern polyethylene piping, was not damaged except in locations where building collapse severed service connections. Although extensive damage occurred at several 380-kV substations, these difficulties were not a major factor in power restoration due to the existence of 380-kV transmission lines that bypassed the damaged stations. Power from the bypass facilities was rerouted to the distribution system via the 154-kV transmission system, whose substations were much less damaged. The transmission system was repaired quickly, thus promoting timely restoration of customer service in all but the most severely damaged urban areas. Telecommunications interruption ranged from three hours to three days after the earthquake. Although there was no physical damage to network equipment, the performance of the telecommunications system was below expectations due to poor seismic protection of the backup power systems in the central offices. This chapter focuses on four lifeline systems: water supply, natural gas, electric power, and telecommunications. F?c2Byers, William G. et al.,2000Kocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 17 -- performance of transportation systems after the 1999 Kocaeli earthquakeEarthquake Spectra$Vol. 16, Suppl. A, pp. 403-410. Dec.Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; transportation systems; Adapazari; Turkey; manufacturing facilities; Railroads; damage; Ataturk International Airport; Istanbul; Airports; HighwaysHTransportation systems, including railroads, airports, and highways, performed reasonably well during the 1999 Kocaeli, Turkey, earthquake. The Turkish railway system was mainly affected where the surface fault rupture zone crossed the tracks. The damaged railroads were repaired within three days. One train power substation had minor damage, but power was quickly restored using adjacent substations. In addition, the Istanbul Terminal Building train station sustained minor damage; fortunately, there were no injuries because the station was closed at the time. The Ataturk Airport suffered no significant damage, even though generator fuel tanks and emergency batteries were not anchored. Airport systems and facilities did not experience any power failures, and airport operation continued without delays after the earthquake. Such good performance may be attributed to a low level of acceleration at the Ataturk Airport. However, the control tower of Cengiz Topel Military Airport in Izmit suffered significant damage, rendering the tower unusable and reducing airport operations. A massive traffic jam developed on the highways in the earthquake-affected areas immediately after the event and took nearly 24 hours to clear. This traffic jam was caused mainly by the public response to the near-immediate overload/failure of telecommunications systems. Broadcast messages to stay off the roadways were apparently ineffective. Within three days of the earthquake, all roads had been reopened, although at reduced capacity. This chapter describes the Turkish railway system and its performance and repair after the earthquake. It also summarizes the effects of the earthquake on airports, as well as on the overall functioning of the highway systems in terms of emergency response. The structural performance of highways and bridges is described in chapter 18.CDF?d2Imbsen, R. A. et al.,2000qKocaeli, Turkey, earthquake of August 17, 1999: reconnaissance report, Chapter 18 -- impact on highway structuresEarthquake Spectra$Vol. 16, Suppl. A, pp. 411-435. Dec.Izmit; Kocaeli; Turkey earthquake; Aug. 17; 1999; highway bridges; highways; Trans-European Motorway; Turkey; Arifiye bridge; Sakarya River Bridge; Bolu Tunnel; Toll plazas; collapse; Reinforced concrete bridges; damageThe effects of the Kocaeli, Turkey, earthquake on highways and bridges were reported immediately after the earthquake by District 1 of the Karayollari Genel Mudurlugu (KGM) and the Highway General Ministry. The KGM observations focused on the E-80 Trans European Motorway (TEM), the primary route connecting Istanbul to Ankara. The reconnaissance team added observations for a broader range of regional and local routes approximately two or three weeks after the event. A figure presented in the paper shows the damage distribution and highlights key case studies. In view of the earthquake intensity, overall damage to the highway system was remarkably low. Observable damage to the TEM was concentrated over a 65-km section from west of Izmit to near Akyazi in the east. Minor damage to bridges was also observed in a few isolated locations, including Istanbul, Yalova, Geyve, and near Duzce. Damaged facitilies were located almost exclusively on recent Quaternary deposits. No damage to tunnels was reported. With a few notable exceptions, the damage to the highway infrastructure was minor. This chapter reviews bridge damage and collapse and describes examples of roadways distressed by both fault crossings and shaking as well as minor bridge damage. It also summarizes observations of highway and bridge damage in a comprehensive database. The performance of the mechanically stabilized earth (MSE) retaining wall at the approach fill of the collapsed Arifiye Road overcrossing of the TEM is described in chapter 9. This report does not address roads that were submerged when the land subsided, such as the seaside roadways near Golcuk and Sapanca. Chapter 17 discu  the Pacific Northwest. The attenuation characteristics of horizontal peak ground accelerations (PGA) and 5 percent damped pseudovelocity (PSV) were studied for various subsets of the total database. The data suggests that PGA tend to saturate at small source-to-site distances and large magnitudes. Unprocessed data was added to the database, and the attenuation of PGA with distance was considered. The results of the data analysis were used to establish the proper form of regression equations for estimating PGA and PSV at firm-soil sites in the Pacific Northwest. The regression equations were evaluated for accuracy in predicting the response spectra of accelerograms recorded at Olympia and Seattle, Washington, during the 1949 and 1965 Puget Sound earthquakes and the spectra of weaker motions recorded at Tacoma, Washington, and Portland, Oregon, during the latter event.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23950F? 4!Mendoza, L. Reyes, A. Luco, J. E.19918Ambient vibration tests of the Mexicali General HospitalEarthquake SpectraVol. 72, pp. 281-300. MayAmbient vibration tests; reinforced concrete structures; Reinfo s; Earthquake-Resistant Design A two-level seismic assessment procedure for reinforced concrete frame buildings is presented. The intent of the procedure is to determine the risk, in terms of annual probability of exceedance, associated with two limit states, a serviceability limit state and a survival, or ultimate, limit state. The serviceability limit state is determined by elastic response calculation, but the survival limit state analysis attempts to identify the strength and ductility of the critical collapse mechanism, and hence its probability of exceedance by comparison with reference spectra. The basis for identifying the critical collapse mechanism is a modified form of capacity design principles which allows local element failure provided overall structural integrity is not jeopardized.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Constantinou, M. C. et al.,19915Displacement control device for base-isolated bridgesEarthquake SpectraVol. 72, pp. 179-200. MayBridges; base isolation; structural control; Sliding; bearings; Teflon; Displacements (structural); Energy dissipation; Structural Dynamics%An isolation system consisting of sliding Teflon bearings and displacement control devices is described for the seismic protection of bridges. The system utilizes multidirectional Teflon bearings for accommodating thermal movements and for providing the isolation mechanism and displacement control devices which exhibit bilinear behavior with controlled stiffness and characteristic strength. The devices provide rigidity for service loads below their characteristic strength and restoring force and energy dissipation for strong earthquake forces.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395.F?4Stanton, J. F. Roeder, C. W.1991/Advantages and limitations of seismic isolationEarthquake SpectraVol. 72, pp. 301-324. MayIsolation; design; Base isolation; Dynamic properties; Faults; Hysteresis; Rubber bearings; Displacements (structural); Earthquake-Resistant DesignVThis paper explores the limits of the applying of equivalent linear analyses to achieve structural isolation from ground motions likely to cause large displacements. The effectiveness of an isolation system depends partly on the capacity of the system to lengthen the natural period of the structure. However, the extent of the lengthening is bounded above by buckling in systems based on elastomeric bearings and by the available coefficient of friction in sliding systems. Limiting values for the period are developed, and alternative approaches to isolation which avoid the limits are presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4Brune, J. N. Anooshehpoor, A.1991AFoam rubber modeling of the Lotung Large-Scale Seismic ExperimentEarthquake SpectraVol. 72, pp. 165-178. MayPhysical models; soil-structure interaction; Forced vibration tests; Taiwan; Mathematical models; Reinforced concrete; nuclear reactor containment; Structural DynamicsThe main objective of this experiment was to validate the present methods for predicting dynamic soil-structure interaction. A further study, discussed in this paper, was conducted in which a layered foam-rubber model was constructed representing the soil and structure at the site of the original 1/4-scale containment based on the geophysical data provided. A forced vibration test was conducted using steady-state and impulsive forcing functions. Model transfer functions (from control motion to the top of the containment and from downhole stations to the surface) are compared with the observed ones using data from five earthquakes recorded in Lotung, Taiwan, from April-November, 1986. The effects of a stiff backfill on the response of the containment are also investigated.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395@F?4!Ho, C. L. Kornher, K. Tsiatas, G.1991;Ground motion model for Puget Sound cohesionless soil sitesEarthquake SpectraVol. 72, pp. 237-266. MayPuget Sound; Washington; ground motion; soil conditions; Pacific Northwest; Noncohesive soils; Amplification; Response spectra; Engineering SeismologyTThis paper presents the findings of a study to model earthquake ground motion of soil sites in the Puget Sound, Washington, basin. The study presents the selection of a base response spectrum, a ground motion model, and associated input parameters for the ground motion model that are appropriate for the Puget Sound basin. The computer program SHAKE was used to evaluate the spectral amplification of different sites. Parameters for SHAKE were determined from standard penetration test data. Also discussed are the results of sensitivity studies on spectral amplification of the site conditions.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395*LF? 4 Crouse, C. B.1991SGround-motion attenuation equations for earthquakes on the Cascadia subduction zoneEarthquake SpectraVol. 72, pp. 201-236. May~Pacific Northwest; ground motion; Cascadia subduction zone; soil conditions; Attenuation; Acceleration; Engineering Seismology An extensive ground-motion database was compiled for earthquakes occurring in subductio xpp. 144 pages. Oct.Philippines; earthquakes; 1990; Lifeline systems; damage; Transportation systems; Socioeconomic aspects; Disaster relief; Structures; Museums; Luzon; Philippines earthquake; July 16; Earthquake DamageOn July 16, 1990, an Ms 7.8 earthquake occurred on the Philippine and Digdig faults in the central part of the island of Luzon, about 200 km north of Manila in the Republic of the Philippines. Estimated deaths were 1283 and estimated injuries were 2786 in the stricken areas. Ground shaking had severe effects on engineered works in several locations. Damage to Baguio was particularly severe: several modern highrise structures, designed using the Uniform Building Code, collapsed or were severely damaged. The investigators have been unable to determine whether the designs conformed to the code or whether the as-built condition conformed to the designs. Owing to political disruption, a volunteer investigation team left the U.S. and Canada on August 11, almost four weeks after the earthquake to evaluate damage to lifelines and structures. The results are presented in this volume. Chapter titles are as follows: (1) Geoscience and geotechnical, (2) Preliminary interpretation of aftershock data, (3) Structures, (4) Water, sewer, and hydro system damage, (5) Power systems, (6) Communication systems, (7) Petroleum and gas facilities, (8) Transportation facilities, (9) Social impacts and emergency response, (10) Museums, and (11) Summary and conclusions.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395$F?3Dunbar, W. S. Charlwood, R. G.19918Empirical methods for the prediction of response spectraEarthquake SpectraVol. 73, pp. 333-353. Aug.Response spectra; Amplification; Attenuation; Accelerograms; Sites; Earthquake magnitudes; Ground motion; soil conditions; Engineering SeismologyBThree empirically based procedures used to determine smooth response spectra are the main subject of this paper. The procedures, each of which is based on observed data but on quite different assumptions, are to: (1) scale amplification factors by peak ground motions (Newmark and Hall), (2) compute spectra by means of an attenuation relationship (Campbell; Joyner and Boore), (3) use accelerograms recorded during past earthquakes to obtain a statistical estimate of a response spectrum (for example, Guzman and Jennings; Kimball). Each of these methods is currently being used in seismic hazard analysis. Each procedure is described by means of examples and the results of each are compared. Particular attention is given to comparisons between spectra computed by scaling amplification factors and spectra computed by other means.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23952F?3Sokolowski, T. J.19914Improvements in the Tsunami Warning Center in AlaskaEarthquake SpectraVol. 73, pp. 461-481. Aug.eTsunamis; warning systems; Alaska; Western United States; tsunami warning systems; Canada; SeismologyThe Alaska Tsunami Warning Center (ATWC) has implemented many major changes in order to provide timely and effective tsunami warning services for coastal populations in Alaska and the west coasts of Canada and the United States. The basis for these improvements was the integration of computers and associated applied research developments into the operations. New concepts, developments, procedures, computers, and equipment resulted in a highly automated tsunami warning system which analyzes data from potential tsunamigenic earthquakes in real-time and disseminates critical information to affected coastal populations via satellite and high-speed teletypewriter communication systems. Seismic and tide networks have been enlarged to improve the accuracy and timeliness in determining earthquake parameters and confirming the existence of a tsunami. This paper describes the details of the warning system.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4(Soong, T. T. Masri, S. F. Housner, G. W.1991<An overview of active structural control under seismic loadsEarthquake SpectraVol. 73, pp. 483-505. Aug.Structural Control; active; Experimentation; United States; U.S. Panel on Structural Control Research; Research; Earthquake engineering; Bracing; Damping devices; Earthquake-Resistant DesignThis paper provides an overview of active structural control with special emphasis placed on laboratory experiments using model structures and on full-scale implementation of some active control systems. Included in this paper is a report on the formation of a U.S. Panel on Structural Control Research and some discussion on possible future research directions in this research area.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?4Rodriguez, M. Park, R.1991PRepair and strengthening of reinforced concrete buildings for seismic resistanceEarthquake SpectraVol. 73, pp. 439-459. Aug.Repairs; Strengthening; Reinforced concrete structures; Reinforced concrete columns; Strength; Ductility; Reinforcement; Earthquake-Resistant DesignThis paper summarizes a review of the literature on the repair and strengthening of reinforced concrete buildings in seismic areas, with emphasis on the repair and strengthening of reinforced concrete columns. In particular, experimental and analytical investigations are described which provide information on the strength, ductility, and seismic behavior of reinforced concrete columns repaired and strengthened by jacketing with or without added longitudinal reinforcement placed through the floor structure.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395]F?4 Mittler, E.1990<The California earthquake insurance program: developments inEarthquake SpectraVol. 73, pp. 391-411. Aug.Loma Prieta; California earthquake; Oct. 17; 1989; insurance; Northern California; earthquake; California; legislation; Earthquakes as Natural Disasters; Governmental AspectsmDuring hearings following the 1987 Whittier Narrows and the 1989 Loma Prieta earthquakes, key California legislators were convinced by the testimony of private citizens that privately offered earthquake insurance was inadequate to fully protect homeowners and to ensure the public safety. As a result, in the 1989-1990 legislative session, the State of California enacted over 130 bills related to earthquake safety. Among those was the passage of the Green, Hill, Areias, Farr California Residential Earthquake Recovery Act (SB 2902) establishing mandatory earthquake insurance for all single-family dwellings with homeowners insurance in the state. The reasons why and how this legislation was enacted are examined, as are the contents of the act and the implications for future legislation. The impact of this act on a national earthquake insurance program is also explored.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?4 Shiping, H.1991GThe earthquake-resistant properties of Chinese traditional architectureEarthquake SpectraVol. 73, pp. 355-389. Aug.People's Republic of China; architecture; structural design; Structures; Wooden structures; design; Masonry; pagodas; Structural configuration; Religious structures; Earthquake-Resistant DesignThis paper explains why Chinese traditional architecture has effective earthquake-resistant properties. First, the many factors that affect the response of buildings to earthquakes are presented. The paper goes on to describe the features of Chinese traditional architecture that contribute to reduction of earthquake actions: the shape, configuration, and integrality of the traditional structure, particularly the excellent damping effect of the ductile tenon-mortise joint and the bracket set. An explanation is given for the excellent performance of Yingxian Pagoda and the Guanying Pavilion, timber structures built around 1000 years ago. The ability of masonry pagodas to withstand earthquakes is discussed with respect to nonoccurrence of resonance and the integrality and configuration. In the conclusion, the author answers the question of whether the good seismic- resistant behavior of Chinese traditional buildings resulted from measures deliberately taken by ancient builders.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395'FF?4 Priestley, M. J. N. Calvi, G. M.1991MTowards a capacity-design assessment procedure for reinforced concrete framesEarthquake SpectraVol. 73, pp. 413-437. Aug.Reinforced concrete frames; design; nonlinear response  the 1985 Chile earthquake: implications for the design of structural wallsEarthquake SpectraVol. 74, pp. 607-638. Nov.Chile; reinforced concrete walls; earthquakes; 1985; building codes; design; damage; United States; Reinforcement; walls; structural height; Displacements (structural); Uniform Building Code; 1988 edition; Earthquake-Resistant DesignThe 1985 MS 7.8 Chile earthquake provided a rare opportunity to study the seismic response of buildings with reinforced concrete walls. More than 230 moderate-rise reinforced concrete buildings were located in the coastal city of Vina del Mar at the time of the earthquake. The majority of these buildings relied on structural walls to resist vertical and lateral loads. However, the walls did not have the reinforcement details required in current U.S. codes to ensure ductile response. A survey of damage following the earthquake indicated that most of these buildings sustained no structural damage. The Vina del Mar building inventory is used to evaluate current building code provisions in the U.S. for structural walls.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3Whittaker, A. S. et al.,19919Seismic testing of steel plate energy dissipation devicesEarthquake SpectraVol. 74, pp. 563-604. Nov.Energy dissipation; experimentation; frames; ADAS (added damping and stiffness) devices; nonlinear response; Moment-resisting frames; dynamic properties; Hysteresis; Strengthening; Steel; plates; Braced frames; Shaking table tests; Structural DynamicsIThe seismic performance of steel plate added damping and stiffness (ADAS) elements was investigated through a series of subassemblage experiments and by the earthquake simulator testing of a three-story ductile moment-resisting space frame (DMRSF) upgraded with ADAS elements. The hysteretic behavior of the ADAS elements was obtained in subassemblage testing for a large number of yielding cycles. The implications of the research results for the design and upgrade of buildings using ADAS elements, and potential uses for ADAS elements, are presented in the latter part of the paper.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3Filiatrault, A.19915Seismic evaluation of modular office furniture systemEarthquake SpectraVol. 74, pp. 529-541. Nov.Nonstructural elements; response; dynamic properties; Office furniture systems; modular; Partitions; Ground motion; nonstructural systems; Panels; Loma Prieta; California earthquake; Oct. 17; 1989; Northern California; earthquake; Shaking table tests; Structural Dynamics3This preliminary experimental study consisted of visually observing the behavior of a full-scale typical furniture unit under uniaxial (horizontal) components of various earthquake ground motions. Two different orientations of the unit relative to the direction of the earthquake excitation were considered.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23951F?3&Liu, S. C. Lagorio, H. J. Chong, K. P.19915Status of U.S. research on structural control systemsEarthquake SpectraVol. 74, pp. 543-550. Nov.tStructural Control; active; research; passive; United States; Seismic loads; Wind loads; Earthquake-Resistant DesigngThis paper assesses the current status of control technology and its potential application to structural safety against seismic, wind, and other dynamic loads. An intensive effort under way to develop a national research program is described. Research needs and important problems remaining from both the technological and practical standpoints are suggested.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395:F?3EERI Survey Team, 1991>Costa Rica earthquake of April 22, 1991: reconnaissance reportEarthquake Spectra%Vol. 7, Suppl. B, pp. 127 pages. Oct.Costa Rica; earthquakes; 1991; Lifeline systems; damage; Transportation systems; Socioeconomic aspects; Industrial plants; Hotels; Disaster planning; Earthquake Damage; Limon region A M 7.5 earthquake occurred on Apr. 22, 1991, in the Talamanca Mountains of Costa Rica. The earthquake was felt throughout Costa Rica and northern Panama. The earthquake caused 53 deaths, destroyed or severely damaged 7145 homes and businesses, and left approximately 30,000 people homeless. The Costa Rican government estimates over 500 million dollars in property damage and lost revenue. The same day, in conjunction with the National Research Council of the United States National Academy of Sciences, the Earthquake Engineering Research Inst. (EERI) established a multidisciplinary team of scientists and engineers to coordinate a postearthquake investigation of the Costa Rica earthquake. The team represented seven study areas: geosciences, geotechnical aspects, buildings, industrial facilities, bridges, lifelines, and socioeconomic aspects. Each of these areas was examined by EERI member volunteers who were assisted by numerous other private individuals, agencies, and companies. The chapters reflect the topics of study.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lca{!F?3 Schiff, A. J.1991,Philippines earthquake reconnaissance reportEarthquake Spectra%Vol. 7, Suppl. A,  sistance to earthquake forces. This paper treats principal concerns in designing, building and using seismically resistant structures, and reviews factors affecting success. Ways of improving the availability and use of earthquake engineering knowledge are suggested, including interdisciplinary communication, research and technology transfer, continuing education, and quality control. Conclusions and appendix questions suggest further study and action useful in any seismic region to help assure actual compliance with goals discussed.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23952F?3Taylor, C. E. et al.,1992=Seismic code decisions under risk: the Wasatch front illusionEarthquake SpectraVol. 81, pp. 35-55. Feb. Utah; seismic risk; building codes; Wasatch front; Los Angeles; structural damage prediction; Southern California; Public policy; California; southern; Seismicity; Loss analysis; Probability theory; earthquake hazards; Cost analysis; structural design; Steel frames; design; Braced framesRegions of low to moderate seismicity but high catastrophic earthquake loss potential pose special issues with respect to seismic design codes as well as other significant policy decisions. These seismic design code decisions hinge on the amount of initial costs and on the size and certainty of benefits from increased design requirements. Since these decisions are made by government officials, these costs and benefits are distributed among various stakeholders in the community. This paper explains this perspective and clarifies earthquake risk methods needed to address these seismic design force level decisions in the Wasatch front, Utah, area and, as a point of comparison, for the city of Los Angeles.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E23954F?3Reitherman, R.19929The effectiveness of fault zone regulations in CaliforniaEarthquake SpectraVol. 81, pp. 57-77. Feb.[California; legislation; California Div. of Mines and Geology; faults; California Seismic Hazards Mapping Act; fault zones; Special studies zones; Sites; Alquist-Priolo Special Studies Zones Act; Geologic hazards; Construction; Earthquake hazards; United States; Land use; Damage; Loss analysis; Design; structural damage prediction; Public policyIn 1990, a study was completed for the California Div. of Mines and Geology on the effectiveness of California's fault zone regulations (the Alquist-Priolo Special Studies Zones Act and associated policies and activities). The act, passed in 1972, instituted the following elements of a statewide mandatory approach for dealing with the hazard of surface fault rupture: state mapping of fault zones where active faults are suspected; local government imposition of the requirement of a geologic study on new building projects within these zones; review procedures for the studies submitted by an applicant's geologist; prohibition of the siting of projects on active faults; and notification of real estate purchasers that a property is located within a zone. This paper presents the results of that evaluation and comments more broadly on applying the Alquist-Priolo model to other regions and to other geologic hazards.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?3+Bush, T. D. Wyllie, L. A., Jr. Jirsa, J. O.1991EObservations on two seismic strengthening schemes for concrete framesEarthquake SpectraVol. 74, pp. 511-527. Nov.Strengthening; Reinforced concrete frames; dynamic properties; Failure; Strength; Stiffness; Dowels; Steel; bracing; Earthquake-Resistant DesignA large-scale model of a nonductile concrete frame with columns susceptible to shear failure was retrofitted with two strengthening schemes. The model is a prototype of buildings constructed in the 1950s and 1960s. In the first scheme, full-height concrete piers were added to the original columns. In the second scheme, a steel X-bracing system was attached to the exterior surface of the frame. The response of the two schemes was compared under cyclic loading to determine differences in strength, stiffness, and failure modes.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3Rovelli, A. et al.,1991oFeasibility of the use of microtremors in estimating site response during earthquakes: some test cases in ItalyEarthquake SpectraVol. 74, pp. 551-561. Nov.Soft soils; amplification; Italy; sites; Microseisms; soil conditions; Response spectra; soils; Ground motion; geologic conditions; Engineering SeismologyThe feasibility of using microtremors to estimate the amplification of seismic waves at soft sites in Italy is explored. Microtremors were measured at three soft sites and nearby hard sites at night when the cultural noise was minimum. These soft sites were selected as those showing the largest amplifications of ground motion during earthquakes as compared to the records on the hard sites or with respect to the predicted spectra. Soft-to-hard site microtremor spectral ratios were compared with the corresponding acceleration spectral ratios. A rough estimate of the shape and level of spectral amplification is obtained from the microtremor data in all three cases. However, the details of the soft-to-hard site spectral ratio are not reproduced and some differences appear in (1) the frequency at which the maximum amplification occurs and (2) the bandwidth of the significant amplification. More testing of the method is needed before its wider use for microzonation in Italy can be recommended.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395BWF0F?3 Wood, S. L.1991~Performance of reinforced concrete buildings during ake City, Utah. A total of 36 on-site interviews were conducted, 13 each in Salt Lake County and Palo Alto, and 10 in Charleston, with planning and building inspection departmental staff, elected officials, consultants, and representatives of real estate interests. To supplement interview data, extensive documentary information, including plans, ordinances, agency reports, research publications, newspaper accounts, and other documentary materials was collected. Conclusions are presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395/ F?3 Michaels, S.19925New perspectives on diffusion of earthquake knowledgeEarthquake SpectraVol. 81, pp. 159-174. Feb.Earthquake engineering; knowledge; technology transfer; information dissemination; Public policy; earthquake engineering knowledge; Seismology; Washington; British Columbia; Canada; Earthquakes as Natural Disasters; Governmental AspectsThis paper contrasts different perspectives concerning the diffusion of earthquake knowledge among non-scientific audiences. The perspective that underlies much of current information dissemination efforts is a "producer-user" model. This model assumes a stable set of knowledge producers and an identifiable set of knowledge users. An alternative perspective is an "issue networks" model. This model assumes a more fluid set of actors and issues linked by common concerns about earthquake hazards. This latter model is suggested as a more accurate depiction of knowledge diffusion within the state and local earthquake policy arenas. This portrayal also leads to consideration of new strategies for disseminating seismological, earthquake engineering, and related knowledge.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395]@F?3 Scott, S.1992AEarthquake engineering: observations from California's experienceEarthquake SpectraVol. 81, pp. 133-158. Feb.!California; earthquake engineering; Critical facilities; Seismic safety; structures; inspection; Sites; Building codes; Legislation; structural design; Seismic risk; Governmental aspects; Public policy; knowledge; technology transfer; information dissemination; Earthquake-Resistant Design\A building's structural quality and seismic resistance are determined by decisions at each step in design, construction, management, and maintenance. Key determinants are design-team skills, grasp of seismic design issues, and communication. In seismic regions, the design of all structures should incorporate adequate re t, the lateral displacement beyond which the lateral load carrying capacity of the isolator deteriorates, is also defined. Results are compared to those obtained using a single bearing fabricated and tested under various normal loads.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3Tobin, L. T. et al.,1992-California at risk: where do we go from here?Earthquake SpectraVol. 81, pp. 17-34. Feb./Loma Prieta; California earthquake; Oct. 17; 1989; legislation; Northern California; earthquake; California; earthquake hazards; Disaster planning; Seismic safety; mitigation; Residential buildings; Geologic hazards; mapping; Houses; Public policy; Earthquakes as Natural Disasters; Governmental AspectsOIn 1986, the state of California embarked on a comprehensive earthquake hazard reduction program described in "California at Risk: Reducing Earthquake Hazards 1987-1992." This program identifies hazard reduction efforts for existing development, emergency response, future development, recovery planning, education, and research. The goal is to reduce the state's earthquake hazards significantly by the year 2000. This paper reviews the development of the program, the state's progress toward hazard reduction, seismic safety legislation, and refinements in the program's second five years.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3May, P. J. Stark, N.1992(Design professions and earthquake policyEarthquake SpectraVol. 81, pp. 115-132. Feb.Public policy; professional practice; building codes; structural design; Seismic safety; legal aspects; Design; profession; Pacific Northwest; Seismic risk; Professional practices; Portland; Oregon; Washington; Puget Sound; Earthquakes as Natural Disasters; Governmental AspectsDThis paper addresses the role of the design professions in enhancing seismic safety as evidenced by interviews with design professionals in the Pacific Northwest. Key policy issues of relevance to this discussion concern the role of codes and other regulatory efforts in P number of discrete masses associated with transnational degrees-of-freedom acting in that direction. The discrete model considers the flexibility of the diaphragms and the rotations of the walls, which are included in the global transnational degrees-of-freedom through static condensation. Soil-structure interaction effects can be easily incorporated in the method. The applicability of the method in the study of the dynamic response of an unreinforced masonry structure with flexible diaphragms is presented. The structure, an old firehouse located in Gilroy, California, was instrumented by the California Strong Motion Instrumentation Program. Instrumented records of the dynamic response of the firehouse in Gilroy during the 1989 Loma Prieta earthquake are available. The discrete dynamic model presented in this work is used to reproduce the recorded dynamic response of the Gilroy firehouse during the Loma Prieta earthquake.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395fKLF?3'Mostaghel, N. Kelly, J. M. Clark, P. W.19924Stability of R-FBI bearings: analysis and experimentEarthquake SpectraVol. 82, pp. 259-277. MayBase isolation; dynamic properties; Resilient friction isolation systems; Displacements (structural); Lateral loads; Stability; Rubber bearings; Experimentation; Sliding; Structural Dynamics; Structural Components<The resilient-friction base isolator (R-FBI) is a device which can be incorporated into the foundations of new and existing structures to protect them from damaging earthquake ground motions. The device consists of a short column composed of a set of identical flat rings with an elastic core (reinforced rubber plug). The elastic core is positioned such that it carries no axial load and distributes the lateral displacement uniformly across the clear height of the column. This paper presents an approximate analytical model for the stability analysis of an R-FBI bearing as a short column. Assuming no negative pressure at the interfaces of the flat rings, the values of the critical lateral displacement and the critical vertical load are defined and calculated in terms of the system's parameters. The upper limit of'v8F?3Berke, P. R. Beatley, T.1992aA national assessment of local earthquake mitigation: implications for planning and public policyEarthquake SpectraVol. 81, pp. 1-15. Feb.Earthquake hazards; mitigation; governmental aspects; United States; Charleston; South Carolina; land use; earthquake hazard mitigation; Palo Alto; California; Northern California; Utah; Salt Lake City; Public policy; Urban and regional planning; Earthquakes as Natural Disasters3This paper focuses on earthquake mitigation activities of local governments. It is derived from a comprehensive study of local seismic hazards planning programs throughout the United States. Data for the study were obtained from a nationwide mail survey of mitigation efforts of local government planning programs and three case studies of such programs. During the fall of 1986, a mail questionnaire was sent to planning directors of 260 communities with populations of 10,000 or more. These communities were located in the 22 states with high seismic risk zones (seismic zones 3 and 4). The response rate for the sample was 79.9 percent. The case studies entailed detailed on-site investigations during 1988 and 1989 of specific mitigation efforts of three local governments: Charleston, South Carolina; Palo Alto, California; and Salt L  ages for individual protective actions, and assumptions about the nature of injuries. Research has tended to consider primarily the demand side of earthquake injury prevention, focusing on the injured rather than the uninjured. Case series investigations have tended to be descriptive rather than analytical and be undertaken from a clinical rather than an epidemiological perspective, documenting medical aspects of earthquake injuries. Linking these injuries to the risk factors associated with them has not been as systematically studied. This paper proposes an approach for casualty reduction research to fill knowledge gaps. It includes steps to integrate future casualty data and assessment efforts into casualty modeling and ongoing earthquake policy information.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 Umolished, and 20 percent have not complied. This paper examines the financial impacts of the ordinance on the local community and the possible implications for other cities.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3Durkin, M. E. Thiel, C. C., Jr.19922Improving measures to reduce earthquake casualtiesEarthquake SpectraVol. 81, pp. 95-113. Feb. Casualties; Humans; injuries; Public policy; Medical aspects; Loma Prieta; California earthquake; Oct. 17; 1989; Northern California; earthquake; Santa Cruz County; California; Damage; Nonstructural elements; Structures; Loss analysis; Earthquakes as Natural Disasters2Current earthquake casualty reduction measures are examined, and recommendations made for needed changes. Key new approaches are outlined, and a new framework for understanding casualty reduction measures is presented. The framework considers both issues of demand for medical services and supply within primary, secondary, and tertiary prevention aspects of each. It is used to assess current measures against recent empirical data and to suggest changes that incorporate new data and methods. Issues include the management of emergency medical services, mess  influencing design practices. Findings are presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395SpF?3Comerio, M. C.1992FImpacts of the Los Angeles retrofit ordinance on residential buildingsEarthquake SpectraVol. 81, pp. 79-94. Feb.;Los Angeles; Los Angeles Earthquake Hazards Reduction Ordinance; structural strengthening; masonry structures; Strengthening; building codes; Southern California; Residential buildings; Legislation; Public policy; California; southern; Cost analysis; Apartment buildings; Seismic safety; Earthquake-Resistant Design The Los Angeles Earthquake Hazards Reduction Ordinance, enacted in 1981, required owners of all unreinforced masonry (URM) buildings to comply with retroactive seismic standards. Among the 8100 URM buildings are approximately 1600 residual buildings with 46,000 housing units. As of March 1991, 55 percent are complete, 13 percent are in progress, 12 percent have been de fects, and the influence of bombardment of elastomers by high-energy radiation.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395FF?3+Litehiser, J. Marrone, J. Abrahamson, N. A.1992XA preliminary model of firm foundation acceleration hazard in the San Francisco Bay AreaEarthquake SpectraVol. 82, pp. 225-257. MaySan Francisco Bay Area; ground motion; acceleration; faults; San Francisco Bay region; maximum horizontal; California; northern; Northern California; Maps; San Andreas fault; Hayward fault; San Francisco; Civic Center; Oakland; Attenuation; Rocks; Soils; Soil conditionsThe results of a study of earthquake peak horizontal component acceleration hazard are presented for the nine counties of the San Francisco Bay Area. The main objective of the study is to develop an interim and simple estimate of the regional earthquake acceleration hazard using an extended hazard algorithm that allows a more complete consideration of recently published regional earthquake source parameters. Complexities of source directivity, soft foundation conditions, and site topography are not considered. Results are presented in the form of contour maps of acceleration on rock or stiff soil with a probability of exceedance of 10 percent for the next 20 and 50 years starting with 1990.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395 F?3 Jeng, V. Kasai, K. Maison, B. F.1992OA spectral difference method to estimate building separations to avoid poundingEarthquake SpectraVol. 82, pp. 201-223. MayaPounding; structural height; structural separation; Random vibration analysis; structural pounding; Damping; Hysteresis; Nonlinear structures; Nonstructural elements; Response spectrum analysis; Spectral difference method; Displacements (structural); Moment-resisting frames; nonlinear response; Multistory frames; Linear structures; Structural DynamicsA method to estimate the likely minimum building separation necessary to preclude seismic pounding is presented. The method is based on random vibration theory. The accuracy is demonstrated by numerical experiments using nine artificial and six actual earthquake records. The relations between the minimum separation, period, height, damping, and earthquake type are discussed. Example applications of the theory are presented. The effects of inelastic hysteretic building behavior are also discussed.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395O\F?3Tena-Colunga, A.1992NSeismic evaluation of unreinforced masonry structures with flexible diaphragmsEarthquake SpectraVol. 82, pp. 305-318. May:Masonry structures; analysis; linear response; Diaphragms; Multidegree-of-freedom structures; Gilroy; California; Loma Prieta; California earthquake; Oct. 17; 1989; firehouses; Northern California; earthquake; Lowrise structures; Central California; Finite element method; Masonry walls; Soil-structure interactionA discrete linear-elastic, multidegree-of-freedom dynamic model is presented for the analysis of unreinforced masonry structures with flexible diaphragms. The discrete multidegree-of-freedom model represents the dynamic response of a structure in a given direction by a reduced  damping on inelastic spectra is thoroughly verified. Mathematical expressions for a tripartite model of design spectra for inelastic systems are presented and tested for a ground motion record representative of a major destructive earthquake. Results are presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395ssViscous damping devices; nonlinear response; response; design; Elastoplastic analysis; damping devices; Single degree-of-freedom systems; Energy dissipation devices; dynamic properties; building codes; stiffness; Elastic structures; Damping; linear structures; nonlinear structures; Design spectra; Structural DynamicsThe results of several studies on the effects of supplemental viscous damping on the response of elastic and elasto-plastic single degree-of-freedom systems are used to provide insight to the effects of large damping on the earthquake response of buildings and the interpretation of studies reporting the equivalent damping and increased stiffness characteristics of specific types of supplemental energy dissipation devices. Extension to multi-story buildings is discussed briefly. Conversion of the properties of viscous, viscoelastic, friction, and metallic yield device characteristics to equivalent viscous damping are proposed. Specific recommendations for the incorporation of the effects of supplemental energy dissipation devices in the code design process are given.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395Q_f8F?3Perry, C. L. et al.,1993ASeismic upgrade in San Francisco using energy dissipation devicesEarthquake SpectraVol. 93, pp. 559-579. Aug.FADAS (added damping and stiffness) devices; design; nonlinear analysis; analysis; Loma Prieta; California earthquake; Oct. 17; 1989; office buildings; lowrise structures; damping devices  with the response of typical welded connections with and without column-web stiffeners. A similar set of three specimens was tested to assess the composite effect for connections with bolted endplates. A final, seventh bolted beam-column connection, with composite sections for both the column and the beam, was also tested.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395} F?3Tsai, K. C. et al.,1993TDesign of steel triangular plate energy absorbers for seismic-resistant constructionEarthquake SpectraVol. 93, pp. 505-528. Aug.VEnergy absorption devices; design; dynamic properties; nonlinear response; tall buildings; steel frames; Steel; plates; ADAS (added damping and stiffness) devices; story drift; analysis; Cyclic loads; Triangular-plate ADAS (added damping and stiffness) devices; damping devices; Pseudodynamic tests; braced frames; Earthquake-Resistant DesignBuilding structures must be constructed to dissipate a large amount of seismic energy in order to achieve economical earthquake-resistant constructions. In this paper, recent research findings on the effectiveness of using steel triangular plates welded as the added damping and stiffness (ADAS) devices for earthquake-resistant structures are presented. Experimental results indicate that a properly welded steel triangular-plate added dampin  hose who may do building design in that country. The introduction discusses the main characteristics of earthquakes in China, some major earthquake disasters of the past, and a brief history of seismic design in China. The paper goes on to relate some new features of the recently promulgated seismic code which includes a new design spectrum, how to identify liquefiable soil, the three levels of seismic protection, and the two-phase design. The paper also presents the seismic design of multistory brick and reinforced concrete buildings, which differs somewhat from that of other countries, and three examples of actual design.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3Pezeshk, S. et al.,1993SSeismic vulnerability evaluation of bridges in Memphis and Shelby County, TennesseeEarthquake SpectraVol. 94, pp. 803-816. Nov.Memphis; Tennessee; highway bridges; bridges; vulnerability; seismic risk; Shelby County; New Madrid seismic zone; Central United States; Earthquake-Resistant Design The focus of this paper is to develop a screening procedure to obtain information and assess vulnerability of bridges located in the New Madrid seismic zone (NMSZ). This screening methodology includes structural elements, site, foundation, and importance of the bridge. An inventory of the river-crossing bridges in Memphis and Shelby County is made using the developed screening procedure; potentially hazardous bridges that require further detailed seismic evaluation and/or immediate seismic retrofitting are identified.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3$Park, R. Rodriguez, M. Dekker, D. R.1993SAssessment and retrofit of a reinforced concrete bridge pier for seismic resistanceEarthquake SpectraVol. 94, pp. 781-801. Nov.Reinforced concrete; bridge piers; strengthening; experimentation; repairs; New Zealand; reinforced concrete bridge piers; Axial loads; Anchors (structural); Cyclic loads; Highway bridges; Earthquake-Resistant DesignTypical structural deficiencies in some reinforced concrete bridges designed for seismic resistance before current seismic codes were introduced are briefly outlined. Results of simulated seismic load tests conducted on the critical region of a reinforced concrete bridge pier designed in New Zealand in 1936 are presented. The tests involved the application of compressive axial loading and quasi-static cyclic lateral loading to a full-scale subassemblage representing the column-cap beam region of the as-built pier. Subsequent loading tests were conducted on the pier. In order to improve anchorage, the pier was retrofitted mainly by the addition of steel plates welded to the ends of the plain round longitudinal bars.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3 Viksne, A. Wood, C. Copeland, D.1993KTechnical note: Bureau of Reclamation Strong Motion Instrumentation ProgramEarthquake SpectraVol. 94, pp. 885-887. Nov.United States; U.S. Bureau of Reclamation Strong Motion Instrumentation Program; Dams; strong-motion instrument arrays; ground motion; lifeline systems; Critical facilities; Loma Prieta; California earthquake; Oct. 17; 1989; Northern California; earthquake; Strong Motion Seismometry5The purpose of the Bureau of Reclamation Strong Motion Instrumentation Program is to obtain ground motion data at dams, powerplants, pumping plants, and other lifeline structures affected by shaking from earthquakes. The data obtained from strong motion systems address two important needs: (1) to provide a record of ground motion parameters that can be used in the analysis and design of critical structures, existing or proposed; and (2) to provide a rational basis for inspections or remedial action at structures that have been subjected to earthquake loading.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3+Rabinowitz, N. Steinberg, D. M. Leonard, G.1993.Technical note: when does seismic hazard jump?Earthquake SpectraVol. 94, pp. 877-883. Nov.Earthquake hazards; assessment; Sites; Seismicity; seismic risk; ground motion; Acceleration; prediction; Attenuation; Seismology; Earthquake RiskThe purpose of this note is to present a simple model for identifying critical regions in the space of parameters in which the hazard is substantially larger than the original reference assessment. A key element in the procedure is to assess the effect of simultaneous changes in several parameters. The authors illustrate that plausible changes for several parameters, if made simultaneously, may lead to a jump in assessed hazard that is significantly larger than that caused by a plausible change in any of the individual parameters.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395(F?3!Kakaliagos, A. K. Bouwkamp, J. G.1993WTests on steel and composite beam-to-column connections: strength and stiffness aspectsEarthquake SpectraVol. 94, pp. 755-780. Nov.Steel beam-column joints; bolted; welded; dynamic properties; cyclic loads; experimentation; nonlinear response; Composite beam-column joints; Joints; Welded joints; Strength; Stiffness; End-plates; Structural Dynamics; Structural ComponentsUThe connection interface of seven welded and bolted beam-to-column connections under cyclic alternating loads has been studied. Three fully welded connections were designed to compare the effect of filled-in concrete in a t o tions; energy; urban areas; Cities; Sedimentary basins; Engineering Seismology; TopographyjA hybrid technique, based on mode summation and finite differences, is used to simulate the ground motion induced in the city of Rome by the Jan. 13, 1915, Fucino (Italy) earthquake (M subscript L = 6.8). The technique allows the authors to take into consideration source, path, and local soil effects. The results of the numerical simulations are used for a comparison between the observed distribution of damage in Rome and the computed peak ground acceleration, the maximum response of simple oscillators, and the so-called "total energy of ground motion." The influence of sedimentary basins on damage is examined.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3Hu, S.1993$Seismic design of buildings in ChinaEarthquake SpectraVol. 94, pp. 703-737. Nov.People's Republic of China; building codes; structural design; brick structures; reinforced concrete structures; hotels; design; Multistory structures; Design spectra; Towers; Gymnasia; Earthquake-Resistant DesignThis paper gives a general perspective on the subject of seismic design of buildings in China and may be of special interest to t _ land, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3)Popov, E. P. Yang, T. S. Grigorian, C. E.1993,New directions in structural seismic designsEarthquake SpectraVol. 94, pp. 845-875. Nov.Energy; structural design; hysteresis; Ductility; response spectra; nonlinear; Moment-resisting frames; design; nonlinear response; Steel frames; Energy dissipation; joints; Braced frames; Eccentric bracing; Earthquake-Resistant DesignThis paper first describes the code stipulated seismic force requirements for buildings from the historical point of view. This is followed by examples of the emerging criteria of inelastic seismic spectra for displacement ductility, and number of yield reversals as a function of building period and strength. Novel spatial representations of seismic input energy and hysteresis energy, interpreted as damage energy, are then presented. The available structural resistance countering the imposed seismic demand is illustrated by the ductile behavior of steel moment resisting frames (MRFs) and eccentrically braced frames (EBFs). The paper concludes with a discussion of a practical and versatile frictional energy dissipating connection.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395_ F?3Fah, D. et al.,1993bA new method for the realistic estimation of seismic ground motion in megacities: the case of RomeEarthquake SpectraVol. 94, pp. 643-668. Nov.Rome; Italy; ground motion; earthquakes; 1915; structural damage; acceleration; Fucino; Italy earthquake; Jan. 13; simulation; geologic conditions; soil condi 9-701. Nov.Turkey Flat; California; Central California; sites; ground motion; Monte Carlo method; site response; response; soil conditions; Geologic conditions; central; Engineering SeismologyIn the weak-motion phase of the Turkey Flat blind-prediction effort, it was found that given a particular physical model of each sediment site, various theoretical techniques give similar estimates of the site response. However, it remained to be determined how uncertainties in the physical model parameters influence the theoretical predictions. The authors studied this question by propagating the physical parameter uncertainties into the theoretical site-response predictions using Monte Carlo simulations. The input-parameter uncertainties were estimated directly from the results of several independent geotechnical studies performed at Turkey Flat.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395#ʀF?3Jain, S. K. Das, S.1993zAnalysis of strong motion records from Uttarkashi earthquake for assessment of code provisions for different seismic zonesEarthquake SpectraVol. 94, pp. 739-754. Nov.Uttarkashi; India earthquake; Oct. 20; 1991; strong-motion records; India; earthquakes; building codes; design earthquakes; Response spectra; nonlinear; Earthquake-Resistant DesignFStrong motion records have been obtained at 13 stations during the Uttarkashi earthquake of Oct. 20, 1991 (M = 6.6). A study has been conducted on these time histories to assess the code provisions in India. Emphasis of the study is on evaluating relative consistency of design provisions for different seismic zones in India.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oak 0/E2395; oclcF?3 Pezzullo, A.1994YThe architectural heritage of Campania: protection from and prevention of seismic hazardsEarthquake SpectraVol. 101, pp. 23-42. Feb.Italy; historical structures; earthquakes; 1980; building codes; structural strengthening; cathedrals; rehabilitation; preservation; case studies; Irpinia; Stone; structures; Masonry structures; strengthening; repairs; reconstruction; Palaces; Earthquake-Resistant DesignThis paper concerns the rehabilitation of historical buildings located in seismic areas. The paper covers the following topics: (1) maintenance of historical buildings as an efficient means of minimizing damage from an earthquake, (2) reduction of consolidation, (3) in-depth knowledge as a necessary premise to plan a rehabilitation project, (4) re-evaluation of traditional techniques by incorporating modern materials, and (5) preservation of the function and character of monuments in their changing use and new technological needs. The paper also contains examples of rehabilitation undertaken in the aftermath of the 1980 Irpinia earthquake.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395s F?3Pincheira, J. A.1993HDesign strategies for the seismic retrofit of reinforced concrete framesEarthquake SpectraVol. 94, pp. 817-842. Nov.Reinforced concrete frames; strengthening; design; nonlinear response; Story drift; structural strengthening; Lowrise frames; Bracing; Earthquake-Resistant Design~This paper summarizes some of the results of a series of analytical studies conducted on prototype reinforced concrete frames strengthened with some of the most commonly used rehabilitation techniques. Based on the results of these studies, a design strategy that uses lateral drift rather than lateral strength as the main criterion for the design of retrofit schemes is presented.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395ьF?3Field, E. H. Jacob, K. H.1993Monte-Carlo simulation of the theoretical site response variability at Turkey Flat, California, given the uncertainty in the geotechnically derived input parametersEarthquake SpectraVol. 94, pp. 66 ia earthquakes, and subsequent experiences, have underscored the need for adequate damage assessment prior to seismic rehabilitation. Furthermore, assessment can be enhanced by preventive studies under the guidance of those in charge of hazard mitigation (architects, engineers, etc.) Research procedures must be defined so that findings can be used for damage assessment and as input data for structural analysis and control models. This paper provides evaluations of in-situ and laboratory tests on materials for existing unreinforced masonry structures and, in particular, touches upon the difficulty of interpreting the results of NDE tests. Furthermore, the need for a design of the investigation prepared by persons responsible for the rehabilitation is pointed out.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395!TF?3Levin, B. Bach, M.1994xThe impact of seismic strengthening and code related issues in restoration, renovation, and re-use of historic buildingsEarthquake SpectraVol. 101, pp. 3-21. Feb.>Historical structures; strengthening; restoration; building codes; design; case studies; Los Angeles; office buildings; theaters; residential buildings; commercial structures; Wiltern Theater; Grand Central Square; Southern California; California; California State Historical Building Code; Earthquake-Resistant DesignZTwo case studies involving important Los Angeles historic buildings, the Wiltern Theater and Grand Central Square, illustrate the complexities of code compliance with respect to preservation and programmatic goals, specifically in the areas of seismic retrofit, fire-life safety and disabled access. Successful historic preservation projects can benefit from a thorough pre-design phase and an experienced project team. Modifications and refinements to regulatory procedures, particularly at the local level, could also significantly facilitate restoration, renovation and re-use of historic buildings.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:htt ineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395F?3 Poland, C. D.1994-Repair and retrofit of health care facilitiesEarthquake SpectraVol. 101, pp. 113-123. Feb.Health care facilities; repairs; strengthening; earthquake hazard analysis; damage prediction; cost analysis; California; hospitals; Medical facilities; Structural configuration; vulnerability; structural damage; Seismic risk; Disaster planning; Earthquake-Resistant DesignpWhile since 1973, the design and construction of new California health care facilities have been regulated by special ordinances, pre-existing hospitals have remained largely non-compliant due to the prohibitive costs of upgrading. The special seismic design considerations that are needed for new and existing California health care facilities, a program for assessing the projected performance of these facilities in terms of life-safety and ability to remain operational under various seis st be established. Development of rational standards has been hindered by a limited ability to estimate actual lateral-load capacity of buildings of various materials and in various damage states. Once a policy for acceptable levels of safety is established, however, technical guidelines could be developed which would improve the current situation.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395vF?3Russell, J. E.1994=Post-earthquake reconstruction regulation by local governmentEarthquake SpectraVol. 101, pp. 209-223. Feb.IReconstruction; governmental aspects; post-earthquake policies; building codes; Northern California; structural repairs; structural damage assessment; Loma Prieta; California earthquake; Oct. 17; 1989; historical structures; structural rehabilitation; Los Gatos; California; houses; Oakland; structural strengthening; legislationTwo California cities are the focus of a comparison of the formulation and results of reconstruction policies and standards following the 1989 Loma Prieta earthquake. The Town of Los Gatos and the City of Oakland are very different in size and demography but suffered similar levels of earthquake damage. The technical content of the repair standards and the methods of administration adopted by these two cities provide a contrast in the way local governments handle these issues in the post-earthquake environment. A summary and comparison of the effectiveness of these standards is provided and recommendations are included for efforts to assist and prepare others to establish effective and balanced post-earthquake reconstruction policy.Earthquake Engineering Research Institute, 499 14th St, Suite 320, Oakland, CA, 94612-1934, USA, [mailto:eeri@eeri.org], [URL:http://www.eeri.org] %Lcallno 400/E2395FHF?3 Modena, C.1994Repair and upgrading techniques of unreinforced masonry structures utilized after the Friuli and Campania/Basilicata earthquakesEarthquake SpectraVol. 101, pp. 171-185. Feb.Masonry structures; repairs; strengthening; jacketing; Friuli; Italy; earthquakes; 1976; stone structures; historical structures; 1980; reinforced concrete jacketing; Stone; structures; preservation; Campania-Basilicata; Masonry walls; Earthquake-Resistant DesignThe current Italian seismic code and recommendations include extended sections dedicated to repair and strengthening of existing unreinforced masonry structures. Originally developed in emergency conditions, i.e., for the urgent interventions in the zones stricken by the Friuli and Campania-Basilicata earthquakes, they progressively became the current practice systematically applied in the restoration of masonry structures. Such a trend caused major concern not only with regard to the conservation aspects of cultural heritage, but also from the point of view of structural safety. A better understanding of the needs of repair and strengthening of masonry structures, a better knowledge of the behavior and of the efficiency of the various possible techniques, and a renewed reliance on traditional materials and techniques are needed. In recent years, increasing efforts have been made to provide the scientific basis required to meet such needs.Earthquake Eng 9iaEarthquake SpectraVol. 101, pp. 65-79. Feb.Southern California; structural strengthening; structural rehabilitation; office buildings; computer facilities; Base isolation; reinforced concrete frames; nonlinear analysis; response spectra; structural design criteria; Historical structures; strengthening; design criteria; case studies; Masonry structures; limit design; Residential buildings; Los Angeles County; tall buildingsThis paper presents a discussion of two seismic rehabilitation p