PEER Reports

PEER Reports

Performance-Based Seismic Assessment of Skewed Bridges, PEER Report 2014-01

Peyman Kaviani
Farzin Zareian
Ertugrul Taciroglu
2014

The objective of this study is to assess the seismic behavior of reinforced concrete bridges with skew-angled seat-type abutments through a performance-based methodology. Special attention is given to the exploration of variations in the seismic behavior of such bridges with respect to the angle of skew. Post-earthquake reconnaissance studies have reported that larger values of skew angle adversely affect performance. The idiosyncratic, “multi-phasic,” behavior of skew bridges—observed during initial simulations of the present study—led to the development of a novel assessment methodology...

Theoretical Development of Hybrid Simulation Applied to Plate Structures, PEER Report 2014-02

Ahmed A. Bakhaty
Khalid M. Mosalam
Sanjay Govindjee
2014

Hybrid simulation is a popular testing method for the experimental assessment of structural systems. The primary notion is to test only part of the system physically while simultaneously simulating the rest of the system via computer. While the basic idea is simple to understand, there is surprisingly little theoretical work targeted towards understanding the behavior of the concept and in particular its theoretical limitations. Although much attention has been devoted to reducing perceived error, little is actually known about what the reduction targets should be. In this report an...

Seismic Velocity Site Characterization of Thirty-One Chilean Seismometer Stations by Spectral Analysis of Surface Wave Dispersion, PEER Report 2014-05

Robert Kayen
Brad D. Carkin
Skye Corbet
Camilo Pinilla
Allan Ng
Edward Gorbis
Christine Truong
2014

We present one-dimensional shear-wave velocity (VS) profiles at 31 strong-motion sites in Chile, from Valdivia in southern Chile to Copiapo in the northern Atacama Desert. We estimate the VS profiles with the spectral analysis of surface waves (SASW) method. The SASW method is a non-invasive method that is useful for indirect estimate of the VS at depth from variations in the Rayleigh wave phase velocity at the surface. The purpose of the study is to determine the detailed site velocity profile, the average velocity in the upper 30 m of the profile V...

Northridge 20 Symposium Summary Report, PEER Report 2014-07

H. Tremayne
S. A. Mahin
J. Maffei
D. McCarthy
J. Bwarie
2014

On the 20th anniversary of the Northridge earthquake, more than 600 people gathered in Los Angeles to share the impacts of the 1994 earthquake, highlight accomplishments of the past two decades, and identify necessary steps forward to make our communities more resilient to future earthquakes. This event, called the Northridge 20 Symposium, drew participants from a broad range of disciplines, including earth scientists, structural engineers, risk modelers, emergency managers, and public officials. This summary report presents the findings and recommendations for each of the 11 key areas...

Unbonded Pretensioned Bridge Columns with Rocking Detail, PEER Report 2014-08

Jeffrey A. Schaefer
Bryan Kennedy
Marc O. Eberhard
John F. Stanton
2014

The columns and cap-beams of most bridges are built of cast-in-place reinforced concrete (CIP). The construction of CIP bridges often causes traffic congestion, and following an earthquake, they may be too damaged to function. To address these concerns, the authors have developed a new precast, pretensioned system. The precast feature reduces traffic delays by moving time- consuming construction activities off site. The pretensioning feature tends to reduce residual displacements after an earthquake. To minimize damage, deformations are concentrated at the columns ends, where a steel shoe...

PEER Arizona Strong-Motion Database and GMPEs Evaluation, PEER Report 2014-09

Tadahiro Kishida
Robert E. Kayen
Olga-Joan Ktenidou
Walter J. Silva
Robert B. Darragh
Jennie Watson-Lamprey
2014

This report summarizes the products and results of a study on the collection, processing, and analysis of earthquake ground-motions recorded in Arizona at several recording stations within 200 km from the Palo Verde Nuclear Generating Station in central Arizona. The recorded ground motion in Arizona were compiled and processed according to the Pacific Earthquake Engineering Research Center’s (PEER) record-processing standards. Shear-wave velocity profiles at ten recording stations were measured through the spectral analysis of surface wave dispersion technique. Additionally, “kappa” a...

Evaluation of Collapse and Non-Collapse of Parallel Bridges Affected by Liquefaction and Lateral Spreading, PEER Report 2014-10

Benjamin Turner
Scott J. Brandenberg
Jonathan P. Stewart
2014

The Pacific Earthquake Engineering Research Center and the California Department of Transportation have recently developed design guidelines for computing foundation demands during lateral spreading using equivalent static analysis (ESA) procedures. In this study, ESA procedures are applied to two parallel bridges that were damaged during the 2010 M 7.2 El Mayor-Cucapah earthquake in Baja California, Mexico. The bridges are both located approximately 15 km from the surface rupture of the fault on soft alluvial soil site conditions. Estimated median ground motions in the area in the absence...

Reference-Rock Site Conditions for Central and Eastern North America: Part I - Velocity Definition, PEER Report 2014-11

Youssef M.A. Hashash
Albert R. Kottke
Jonathan P. Stewart
Kenneth W. Campbell
Byungmin Kim
Ellen M. Rathje
Walter J. Silva
2014

As part of the Next Generation Attenuation Relationships for Central and Eastern North America (NGA-East) Project, we have gathered data to define an appropriate reference-rock site condition for CENA. The reference-rock site condition is defined by the S- and P-wave velocities, as well as the local crustal damping (K0). This report deals solely with the definition of the reference P- and S-wave velocities. The significance of the reference-rock definition is that it represents the site condition for which ground motions will be predicted...

Reference-Rock Site Conditions for Central and Eastern North America: Part II - Attenuation (Kappa) Definition, PEER Report 2014-12

Kenneth W. Campbell
Youssef M.A. Hashash
Byungmin Kim
Albert R. Kottke
Ellen M. Rathje
Walter J. Silva
Jonathan P. Stewart
2014

This report presents the results of a comprehensive literature search and limited additional studies that support the recommendation of a probability distribution for the shear-wave (S- wave) site attenuation parameter Κ0, or site kappa, associated with a reference-rock site condition in central and eastern North America (CENA). This study was conducted as part of the Geotechnical Working Group (GWG) activities of the Next Generation Attenuation for Central and Eastern North America (NGA-East) Project conducted by the Pacific Earthquake Engineering Research Center (PEER...

NGA-East Regionalization Report: Comparison of Four Crustal Regions within Central and Eastern North America using Waveform Modeling and 5%-Damped Pseudo-Spectral Acceleration Response, PEER Report 2014-15

Jennifer Dreiling
Marius P. Isken
Walter D. Mooney
Martin C. Chapman
Richard W. Godbee
2014

An important aspect of the Next Generation Attenuation for Central and Eastern North America (NGA-East) project led by the Pacific Earthquake Engineering Research Center (PEER) entails assigning seismic wave attenuation values to major crustal regions. In this study, Central and Eastern North America (CENA) is subdivided into four regions based on the geologic and tectonic setting. The regions are the Central North America (CNA), the Appalachian Province (APP), the Atlantic Coastal Plain (ACP), and the Mississippi Embayment/Gulf Coast region (MEM). Each region is described by a...