PEER Reports

PEER Reports

Central and Eastern North America Ground-Motion Characterization - NGA-East Final Report, PEER Report 2018-08

Christine Goulet
Yousef Bozorgnia
Norman Abrahamson
Nicolas Kuehn
Linda Al Atik
Robert Youngs
Robert Graves
Gail Atkinson
2018

This document is the final project report of the Next Generation Attenuation for Central and Eastern North America (CENA) project (NGA-East). The NGA-East objective was to develop a new ground-motion characterization (GMC) model for the CENA region. The GMC model consists of a set of new ground-motion models (GMMs) for median and standard deviation of ground motions and their associated weights to be used with logic-trees in probabilistic seismic hazard analyses (PSHA). NGA-East is a large multidisciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER),...

An Empirical Model for Fourier Amplitude Spectra using the NGA-West2 Database, PEER Report 2018-07

Jeff Bayless
Norman A. Abrahamson
2018

An empirical ground-motion model (GMM) for shallow crustal earthquakes in California and Nevada based on the NGA-West2 database [Ancheta et al. 2014] is presented. Rather than the traditional response spectrum GMM, this model is developed for the smoothed effective amplitude spectrum (EAS) as defined by PEER [Goulet et al. 2018]. The EAS is the orientation- independent horizontal component Fourier amplitude spectrum (FAS) of ground acceleration. The model is developed using a database dominated by California earthquakes, but takes advantage of crustal earthquake data worldwide to constrain...

Estimation of Shear Demands on Rock Socketed Drilled Shafts subjected to Lateral Loading, PEER Report 2018-06

Pedro Arduino
Long Chen
Christopher R. McGann
2018

This report presents results of an evaluation study on the applicability of current design procedures (based on p-y curves) to the analysis of large-diameter shafts socketed in rock, and the identifi- cation of enhanced moment transfer mechanisms not considered in current design methodologies. For this purpose simplified models, and possible three-dimensional (3D) finite-element method (FEM) models are studied to shed some light on the response of drilled shafts socketed in rock. A parametric study using p-y and considering a wide range of rock properties and rock-socket...

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...