PEER Reports

PEER Reports

Technical Manual for Strata, PEER Report 2008-10

Albert R. Kottke
Ellen M. Rathje
2008

The computer program Strata performs equivalent-linear site response analysis in the frequency domain using time domain input motions or random vibration theory (RVT) methods, and allows for randomization of the site properties. The following document explains the technical details of the program, and provides a user's guide.

Strata is distributed under the GNU Genera l Public License, which can be found at http://www.gnu.org/licenses/.

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Seismic Performance Objectives for Tall Buildings, PEER Report 2008-101

William T. Holmes
Charles Kircher
William Petak
Nabih Youssef
2008

The Pacific Earthquake Engineering Research Center is leading an initiative to develop guidelines for new high-rise construction that will meet intended safety and performance objectives following future earthquakes, particularly when alternative means of design are employed. An initial task of this initiative was to investigate the issues associated with identifying seismic performance equivalent to that achieved by code and whether a higher seismic performance should be targeted for these buildings. Many stakeholders were interviewed for this purpose, and a workshop was convened to...

Modeling of Unreinforced Masonry Infill Walls Considering In-Plane and Out-of-Plane Interaction, PEER Report 2008-102

Stephen Kadysiewski
Khalid M. Mosalam
2008

This report describes a practical analytical model that can be used for the seismic evaluation of unreinforced masonry (URM) infill walls located within a reinforced concrete (RC) frame. The model, which consists of diagonal beam-column members utilizing fiber element cross sections, is suitable for use in a nonlinear time history analysis. The model considers both the in-plane (IP) and out-of-plane (OOP) response of the infill, as well as the interaction between IP and OOP capacities. The behavior is elastoplastic, and limit states may be defined by deformations or ductilities in the two...

Experimental and Computational Evaluation of Current and Innovative In-Span Hinge Details in Reinforced Concrete Box-Girder Bridges - Part 1: Experimental Findings and Pre-Test Analysis, PEER Report 2008-103

Matias A. Hube
Khalid M. Mosalam
2008

During the last three decades, considerable research efforts have sought to improve the seismic design of California highway bridges. However, the in-span hinge regions of concrete box- girders have not been studied adequately. In-span hinges are classified as disturbed regions due to the concentrated bearing loads and the possible existence of utility and maintenance openings, which induce a three-dimensional (3D) behavior. Nevertheless, in-span hinges are commonly designed as two-dimensional (2D) short cantilevers, following standard procedures in ACI318. These designs typically lead to...

Experimental and Analytical Study of the Seismic Performance of Retaining Structures, PEER Report 2008-104

Linda Al Atik
Nicholas Sitar
2008

Recent changes in codes and improved understanding of strong ground motions have led to increased demands in the seismic design of retaining structures. Correspondingly, the dynamic loads computed using currently available design procedures significantly exceed loads used in the design of most of the
existing retaining structures, suggesting that they may have been significantly underdesigned. Field evidence from recent major earthquakes fails to show any significant problems with the performance of retaining structures designed for static earth pressures only. In view of this, an...

Report of the First Joint Planning Meeting for the Second Phase of NEES/E-Defense Collaborative Research on Earthquake Engineering, PEER Report 2009-101

Convened by the NEES Consortium, Inc. and Hyogo Earthquake Engineering Research Center National Research Institute for Earth Science and Disaster Prevention
2009

Following an agreement between the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT) and the U.S. National Science Foundation (NSF), the First Planning Meeting for NEES/E-Defense Collaboration on Earthquake Engineering Research was held in 2004. This meeting laid the groundwork for a five-year joint research program related to improving understanding and reducing the seismic vulnerability of bridges and steel buildings. To formalize the collaboration, two Memorandums of Understanding (MOUs) were executed, one between the NEES Consortium Inc. (NEES Inc.) and the...

Liquefaction and Nonliquefaction Case Histories from the 1976 Tangshan Earthquake, PEER Report 2009-102

Robb Eric S. Moss
Robert Kayen
Liyuan Tong
Songyu Liu
Guojun Cai
Jiaer Wu
2009

A field investigation was carried out to retest liquefaction and nonliquefaction sites from the 1976 Tangshan earthquake in the People's Republic of China (PRC). These sites were carefully investigated in 1978/1979 using standard penetration test (SPT) and cone penetration test (CPT) equipment; however the CPT measurements are obsolete because of the now nonstandard cone that was used at the time. In 2007 a modern cone was mobilized to retest 18 select sites that are particularly valuable because they experienced intense ground shaking, have high fines content, and are classified as...

Performance Evaluation of Innovative Steel Braced Frames, PEER 2009-103

T. Y. Yang
Jack P. Moehle
Bozidar Stojadinovic
2009

Adoption of new structural systems is hampered by the lack of a comprehensive method to evaluate their seismic performance. This report introduces a seismic performance evaluation procedure and demonstrates its application for the suspended zipper braced frame. The performance evaluation procedure includes laboratory and computer simulations. The laboratory simulations may be necessary in cases where behavior of a structural system or its components is inadequately understood and therefore cannot be modeled confidently for computer simulation. By integrating the laboratory specimen...

Advanced Implementation of Hybrid Simulation, PEER Report 2009-104

Andreas H. Schellenberg
Stephen A. Mahin
Gregory L. Fenves
2009

Experimental testing of structures under simulated seismic loading is one of the best approaches to gain knowledge about the response and behavior of structures during earthquakes and to confirm the effectiveness of design methods for new earthquake-resistant structures and the retrofit of existing structures. Hybrid simulation, where a test is executed based on a step-by-step numerical solution of the governing equations of motion for a hybrid model formulated considering both the numerical and physical portions of a structural system, is one of the well-established experimental testing...

Reduced Uncertainty of Ground Motion Prediction Equations through Bayesian Variance Analysis, PEER Report 2009-105

Robb Eric S. Moss
2009

A ground motion prediction equation estimates the mean and variance of ground shaking with distance from an earthquake source. Current relationships use regression techniques that treat the input variables or parameters as exact, neglecting the uncertainties associated with the measurement of shear wave velocity, moment magnitude, and site-to-source distance. This parameter uncertainty propagates through the regression procedure and results in model uncertainty that overestimates the inherent variability of the ground motion. This report discusses methods of estimating the statistical...