PEER Reports

PEER Reports

Selection of Random Vibration Procedures for the NGA-East Project, PEER Report 2018-05

Albert Kottke
Norman A. Abrahamson
David M. Boore
Yousef Bozorgnia
Christine Goulet
Justin Hollenback
Tadahiro Kishida
Armen Der Kiureghian
Olga-Joan Ktenidou
Nicolas Kuehn
Ellen Rathje
Walter J. Silva
Eric Thompson
Xiaoyue Wang
2018

Pseudo-spectral acceleration (PSA) is the most commonly used intensity measure in earthquake engineering as it serves as a simple approximate predictor of structural response for many types of systems. Therefore, most ground-motion models (GMMs, aka GMPEs) provide median and standard deviation PSA using a suite of input parameters characterizing the source, path, and site effects. Unfortunately, PSA is a complex metric: the PSA for a single oscillator frequency depends on the Fourier amplitudes across a range of frequencies. The Fourier amplitude spectrum (FAS) is an appealing alternative...

Capturing Directivity Effects in the Mean and Aleatory Variability of the NGA-West2 Ground-Motion Prediction Equations, PEER Report 2018-04

Jennie A. Watson-Lamprey
2018

We expect there to be locations around a rupture that experience both positive and negative directivity effects more than others. The concept was to develop a simple model of additional mean and standard deviation to add to existing published ground motion prediction equations to account for this. The directivity effect predicted by Chiou and Youngs [2014] using the directivity parameter DPP [Spudich et al. 2013] was selected as the basis for the model. A suite of rupture geometries for strike-slip and reverse ruptures was generated and the mean and standard deviation of the change in the...

Probabilistic Seismic Hazard Analysis Code Verification, PEER Report 2018-03

Christie Hale
Norman Abrahamson
Yousef Bozorgnia
2018

Over the past decade, the use of Probabilistic Seismic Hazard Analysis (PSHA) to assess seismic hazards has expanded, leading to the creation of a number of new PSHA computer codes throughout the industry. Additionally, recent seismic source and ground-motion characterization studies have led to more complex source and ground-motion models, which necessitate implementation in PSHA codes. This project was undertaken to update previous PSHA computer code verification efforts by running an expanded set of verification tests on codes currently in use for PSHA calculations. Following an...

Demand Fragility Surfaces for Bridges in Liquefied and Laterally Spreading Ground, PEER Report 2011-01

Scott J. Brandenberg
Jian Zhang
Pirooz Kashighandi
Yili Huo
Minxing Zhao
2011

This report presents demand fragility surfaces for bridges in liquefied and laterally spreading ground that represent probability P(EDP>edp|IM=im), where a vector of engineering demand parameters is presented and the intensity measure is taken as free-field lateral spreading ground displacement. Equivalent global nonlinear finite element analyses were used to generate the responses of bridges due to liquefaction-induced lateral spreading, while nonlinear dynamic time-history analyses were implemented to determine the response due to seismic shaking. A classification system was developed...

Guidelines for Performing Hazard-Consistent One-Dimensional Ground Response Analysis for Ground Motion Prediction, PEER Report 2014-16

Jonathan P. Stewart
Kioumars Afshari
Youssef M.A. Hashash
2014

Along with source and path effects, site response analysis is a vital component of earthquake ground motion prediction. Semi-empirical ground motion prediction equations (GMPEs) include terms for modeling site response that are based on simple metrics of site condition, such as the time-average shear-wave velocity in the upper 30 m of the site (Vs30). Because site terms in GMPEs are derived from global ground motion databases and are based on incomplete information on the site condition, their predictions represent average levels of site response observed at sites conditional on...

NGA-West2 Equations for Predicting Response Spectral Accelerations for Shallow Crustal Earthquakes, PEER Report 2013-05

David M. Boore
Jonathan P. Stewart
Emel Seyhan
Gail M. Atkinson
2013

We provide ground-motion prediction equations (G MPEs) for the computation of median peak ground motions and response spectra for shallow crustal earthquakes in active tectonic regions. The equations were developed as part of the NGA-West 2 project and are based on a composite data set [Ancheta et al . 2013] that includes global events from 1935 to 2011 spanning a wide magnitude range, plus a large number of small-to-moderate magnitude events from California principally from 1998 to 2011. This data set comprises more than 21,000 records, of which we use a subset of ~16000 records in our...

Moment Resisting Frames Coupled with Rocking Walls Subjected to Earthquakes, PEER Report 2022-03

Mehrdad Aghagholizadeh
Nicos Makris
2022

The high occupancy levels in urban multistory buildings, in association with current safety considerations inevitably leads to a reconsideration of performance objectives. In view of the appreciable seismic damage and several weak-story failures (some at mid-height) of multistory buildings that have been documented after major earthquakes, there has been a growing effort to develop an alternative hybrid structural system by coupling the response of moment resisting frames with rigid/stiff walls which are allowed to uplift and rock during ground shaking; therefore, enforcing a uniform drift...

Update of the BC Hydro Subduction Ground-Motion Model using the NGA- Subduction Dataset, PEER Report 2018-02

Norman Abrahamson
Nicolas Kuehn
Zeynep Gulerce
Nicholas Gregor
Yousef Bozorgnia
Grace Parker
Jonathan Stewart
Brian Chiou
I.M. Idriss
Kenneth Campbell
Robert Youngs
2018

An update to the BCHydro ground-motion model for subduction earthquakes has been developed using the 2018 PEER NGA-SUB dataset. The selected subset includes over 70,000 recordings from 1880 earthquakes. The update modifies the BCHydro model to include regional terms for the VS30 scaling, large distance (linear R) scaling, and constant terms, which is consistent with the regionalization approach used in the NGA-W2 ground-motion models. A total of six regions were considered: Cascadia, Central America, Japan, New Zealand, South America, and Taiwan. Region- independent...

PEER Annual Report 2017 - 2018, PEER Report 2018-01

Khalid Mosalam
Amarnath Kasalanati
Selim Günay
2018

The Pacific Earthquake Engineering Research Center (PEER) is a multi-institutional research and education center with headquarters at the University of California, Berkeley. PEER’s mission is to (1) develop, validate, and disseminate performance-based engineering (PBE) technologies for buildings and infrastructure networks subjected to earthquakes and other natural hazards, with the goal of achieving community resilience; and (2) equip the earthquake engineering and other extreme-event communities with the 21st -century tools that define the current digital revolution. This reports...

Seismic Behavior of Special Concentric Braced Frames under Short- and Long-Duration Ground Motions, PEER Report 2019/09

Ali Hammad
Mohamed A. Moustafa
2019

Over the past decade, several long-duration subduction earthquakes took place in different locations around the world, e.g., Chile in 2010, Japan in 2011, China in 2008, and Indonesia in 2004. Recent research has revealed that long-duration, large-magnitude earthquakes may occur along the Cascadia subduction zone of the Pacific Northwest Coast of the U.S. The duration of an earthquake often affects the response of structures. Current seismic design specifications mostly use response spectra to identify the hazard and do not consider duration effects. Thus, a comprehensive understanding of...