PEER Reports

PEER Reports

Defining the Links between Planning, Policy Analysis, Economics, and Earthquake Engineering, PEER Report 1998-04

Mary Comerio
Peter Gordon
1998

The recently established PEER Center is committed to integrating social science and earthquake engineering research. How should integration proceed? What can social scientists contribute to PEER’s interest in performance-based engineering? These and other questions were addressed at a PEER Workshop on Planning, Policy Analysis and Economics in Earthquake Research which was convened (May 14-15, 1998) to help develop an appropriate research agenda.

Generally, it appears that whereas performance-based engineering seeks optimal solutions to the achievement of given standards, social...

Rocking Response and Overturning of Equipment under Horizontal Pulse-Type Motions, PEER Report 1998-05

Nicos Makris
Yiannis Roussos
1998

In this report the transient rocking response of electrical equipment subjected to trigonometric pulses and near-source ground motions is investigated in detail. First the rocking response of a rigid block subjected to a half-sine pulse motion is reviewed. It is shown that the solution presented by Housner (1963) for the minimum acceleration amplitude of a half-sine pulse that is needed to overturn a rigid block is incorrect. In reality, under a half-sine pulse, a block overturns during its free vibration regime and not at the instant that the pulse expires, as was assumed by Housner....

Effect of Damping Mechanisms on the Response of Seismically Isolated Structures, PEER Report 1998-06

Nicos Makris
Shih-Po Chang
1998

In this report the efficiency of various dissipative mechanisms to protect structures from pulse-type and near-source ground motions is examined. It is first shown that under such motions the concept of equivalent linear damping has limited meaning since the transient response of a structure is more sensitive to the nature of the dissipation mechanism, rather than to the amount of energy dissipated per cycle. Subsequently, physically realizable cycloidal pulses are introduced, and their resemblance to recorded near-source ground motions is illustrated. The study uncovers the coherent...

Behavior And Failure Analysis Of A Multiple-Frame Highway Bridge In The 1994 Northridge Earthquake, PEER Report 1998-08

Gregory L. Fenves
Michael Ellery
1998

The Route 14/Interstate 5 Separation and Overhead bridge, a curved ten-span structural concrete structure, partially collapsed in the 1994 Northridge earthquake. The primary objective of this study is to ascertain the cause of failure by comparing estimates of the capacities and demands of various components in the bridge. A secondary objective is to examine earthquake modeling and analysis recommendations for highway bridges. As part of the examination, nonlinear static analysis (pushover analysis) is used to determine the capacity of a frame. Linearized analyses are compared with...

Empirical Evaluation of Inertial Soil-Structure Interaction Effects, PEER Report 1998-07

Jonathan P. Stewart
Raymond B. Seed
Gregory L. Fenves
1998

Strong motion data obtained over the last decade from sites with instrumented structures and free-field accelerographs has provided an unprecedented opportunity to evaluate empirically the effects of soil-structure interaction (SSI) on the seismic response of structures. Strong motion data were gathered for 58 sites encompassing a wide range of structural systems, geotechnical conditions, and ground shaking levels. System identification analyses were employed with these records to quantify the effects of inertial interaction on modal parameters of structures. Simple indices of free-field...

Interaction in Interconnected Electrical Substation Equipment Subjected to Earthquake Ground Motions, PEER Report 1999-01

Armen Der Kiureghian
Jerome L. Sackman
Kee-Jeung Hong
1999

Abstract cannot be copied from pdf.

Full List of PEER Reports: click here.

Capacity-Demand-Diagram Methods for Estimating Seismic Deformation of Inelastic Structures: SDF Systems, PEER Report 1999-02

Anil K. Chopra
Rakesh K. Goel
1999

The ATC-40 and FEMA-274 documents contain simplified nonlinear analysis procedures to determine the displacement demand imposed on a building expected to deform inelastically. The Nonlinear Static Procedure in these documents, based on the capacity spectrum method, involves several approximations: The lateral force distribution for pushover analysis and conversion of these results to the capacity diagram are based only on the fundamental vibration mode of the elastic system. The earthquake-induced deformation of an inelastic SDF system is estimated by an iterative method requiring analysis...

Task 3: Characterization of Site Response General Site Categories, PEER Report 1999-03

Adrian Rodriguez-Marek
Jonathan D. Bray
Norman Abrahamson
1999

Seismic site response and the amplification of ground motions are significantly affected by the combined effect of the dynamic stiffness of the soil and the depth of the soil. Current design practice, however, either uses an oversimplified approach to soil classification (e.g., "soil" vs. "rock"), or ignores the effect of depth by accounting only for the average shear wave velocity over the upper 100 feet of a site profile (e.g., 1997 UBC). The significant quantity of ground motion data recorded in the 1994 Northridge and 1989 Loma Prieta, California, earthquakes provides an opportunity to...

Adoption and Enforcement of Earthquake Risk-Reduction Measures, PEER Report 1999-04

Peter J. May
T. Jens Feeley
Robert Wood
Raymond J. Burby
1999

These combined studies explore the socio-political implications of the seismic provisions of local building codes. Based on results from a national survey of building code officials, these three complementary studies explore (1) making building codes effective tools in earthquake hazard mitigation at the national level (2) the policy challenges of seismic mitigation in the western U.S., and (3) the role of policy entrepreneurs in the adoption of seismic-related provisions by local governments within California.

The conclusions of these studies are diverse, exploring various aspects...

Seismic Evaluation of 550 kV Porcelain Transformer Bushings, PEER Report 1999-05

Amir S. Gilani
Andrew S. Whittaker
Gregory L. Fenves
Eric Fujisaki
1999

Three 550 kV porcelain transformer bushings were evaluated for their response to severe earthquake shaking. The first bushing was similar to bushings currently in service in the United States; the other two bushings were modified versions of the first bushing. The modifications to the second and third bushings were intended to enhance seismic performance and included added tiers of springs, increased preload, and stiffer gaskets. The dynamic properties, vibration frequencies, and damping ratios of the bushings were evaluated from the experimental data. Tri-directional earthquake simulator...