PEER Reports

PEER Reports

Housing Recovery in Chile: A Qualitative Mid-program Review, PEER Report 2013-01

Mary C. Comerio
2013

The magnitude 8.8 earthquake, and subsequent tsunami, which struck the south central region of Chile on February 27, 2010, affected 75% of the population of the country and damaged or destroyed 370,000 housing units (about 10% of the housing in 6 regions). Within 6 months, the Ministry of Housing and Urban Development published a plan to repair or rebuild 220,000 units of low- and middle-income housing with government assistance within four years. In October 2012, at the midpoint of a 4-year program, 84% of those housing units have started construction and 54% are complete and occupied....

Hybrid Simulation of the Seismic Response of Squat Reinforced Concrete Shear Walls, PEER Report 2013-02

Catherine A. Whyte
Bozidar Stojadinovic
2013

Most industrial and nuclear facilities rely on reinforced concrete (RC) structural walls as their primary seismic lateral-force-resisting components. These walls commonly have an aspect ratio smaller than 0.5 and have a very high stiffness and strength. There is a significant uncertainty regarding the behavior of these walls under earthquake loading, their failure modes, and their expected strengths and deformation capacities. Hybrid simulation is an effective experimental method to examine these issues: it enables simulation of the seismic response of squat and thick shear walls without...

NGA-West2 Campbell-Bozorgnia Ground Motion Model for the Horizontal Components of PGA, PGV, and 5%-Damped Elastic Pseudo-Acceleration Response Spectra for Periods Ranging from 0.01 to 10 sec, PEER Report 2013-06

Kenneth W. Campbell
Yousef Bozorgnia
2013

This report summarizes the development of the NGA-West2 Campbell-Bozorgnia empirical ground motion prediction equation (GMPE). This GMPE updates and supersedes the GMPE developed by Campbell and Bozorgnia (2008) as part of the NGA-West1 Project (Power et al. 2008). We used the extensive and expanded PEER NGA-West2 ground motion database recorded from shallow crustal earthquakes in active tectonic domains to develop a GMPE for the “average” (RotD50) horizontal components of peak ground acceleration (PGA), peak ground velocity (PGV), and 5%-damped elastic pseudo-absolute acceleration...

Update of the Chiou and Youngs NGA Ground Motion Model for Average Horizontal Component of Peak Ground Motion and Response Spectra, PEER Report 2013-07

Brian S.J. Chiou
Robert R. Youngs
2013

This report presents an update to the Chiou and Youngs [2008a] NGA model for the prediction of horizontal peak ground acceleration and 5%-damped pseudo spectral acceleration for earthquakes in active tectonic regions such as California. The update is based on analysis of the greatly expanded NGA-West2 strong motion database. The updated model contains minor adjustments to the functional form developed by Chiou and Youngs [2008a] related to style of faulting effect, hanging wall scaling, scaling with the depth to the top of rupture, the effect of sediment depth, and the inclusion of two...

Semi-Empirical Nonlinear Site Amplification and its Application in NEHRP Site Factors, PEER Report 2013-13

Jonathan P. Stewart
Emel Seyhan
2013

Site factors are used to modify ground motions from a reference rock site condition to reflect the influence of geologic conditions at the site of inte rest. Site factors typically have a small-strain (linear) site amplification that captures impedance and resonance effects coupl ed with nonlinear components. Site factors in current NEHRP Provisions are empirically-derived at relatively small ground motion levels and feature simulation-based nonlinearity. We show that NEHRP site factors have discrepancies with respect to the site terms in the 2008 Next Generation Attenuation (NGA...

Experimental and Analytical Studies on the Seismic Behavior of Conventional and Hybrid Braced Frames, PEER Report 2013-20

Jiun-Wei Lai
Stephen A. Mahin
2013

This report summarizes both experimental and an alytical studies on the seismic response of conventional steel concentrically braced frame systems of the type widely used in North America, and preliminary studies of an innovative hybrid braced frame system: the Strong-Back System. The research work is part of NEES small group project entitled “International Hybrid Simulation of Tomorrow’s Braced Frames.”

In the experimental phase, a total of four full-scale, one-bay, two-story conventional braced frame specimens with different bracing member section shapes and gusset plate-to-beam...

Seismic Design and Performance of Bridges with Columns on Rocking Foundations, PEER Reports 2013-21

Grigorios Antonellis
Marios Panagiotou
2013

Traditional seismic design of bridges includes ductile details that allow bridges to develop substantial inelastic deformations when subjected to severe earthquakes. While bridges designed in this manner may be safe from collapse foll owing an earthquake, they are susceptible to considerable damage and permanent lateral displacements that can impair traffic flow and necessitate costly and time-consuming inspections and repairs (perhaps even demolition). Nowadays, as an alternative design strategy, bridges with columns supported on rocking foundations are designed to undergo large...

Coordinated Planning and Preparedness for Fire Following Major Earthquakes, PEER Report 2013-23

Charles Scawthorn
2013

This report documents activities of a project entitled “Coordinated Planning and Preparedness for Fire Following Major Earthquakes” which built on a previous project entitled “Water Supply in regard to Fire Following Earthquake.”

Voluntary Performance Guidelines for post-earthquake reliability of water supply for firefighting were developed so as to focus the attention of high-risk urban regions on this problem while placing as little demand as possible on fire or other agencies. The Guidelines recommend that incorporated jurisdictions with population exceeding 100,000 and having...

PEER Preliminary Notes and Observations on the August 24, 2014 South Napa Earthquake, PEER Report 2014-13

Grace S. Kang
Stephen A. Mahin
2014

At 3:20 AM, on the morning of August 24, 2014, the San Francisco Bay ar ea was shaken by the South Napa, California, earthquake. According to the USGS, the earthquake had a magnitude (M w) of 6, making it the largest earthquake to strike the San Francisco Bay Area since 1989, when the region was shaken by the magnitude 6. 9 Loma Prieta earthquake. The epicenter was located about 8 km (5 miles) SSW of Napa, a city of about 77,000 people. Other nearby cities include American Canyon, Vallejo, and Sonoma. Located on the north ern shores of San Francisco Bay, this region is a popular tourist...

Stochastic Modeling and Simulation of Near-Fault Ground Motions for Performance-Based Earthquake Engineering, PEER Report 2014-20

Mayssa Dabaghi
Armen Der Kiureghian
2014

A comprehensive parameterized stochastic model of near-fault ground motions in two orthogonal horizontal directions is developed. The proposed model uniquely combines several existing and new sub-models to represent major characteristics of recorded near-fault ground motions. These characteristics include near-fault effects of directivity and fling step; temporal and spectral non-stationarity; intensity, duration and frequency content characteristics; directionality of components, as well as the natural variability of motions for a given earthquake and site scenario. By fitting the model...