PEER Reports

PEER Reports

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

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

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

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...

Influence of Vertical Ground Motion on Bridges Isolated with Spherical Sliding Bearings, PEER Report 2019/08

Rushil Mojidra
Keri L. Ryan

The motivation for this project developed from testing of a full scale building isolated with triple friction pendulum bearings on the E-defense shake table in Japan. The test demonstrated experimentally that the vertical component of ground motion can amplify both the base shear and the story acceleration in the isolated building. Vertical shaking introduced high-frequency variation in the axial force of the bearings, and, consequently, a high-frequency component in the bearing lateral force, which excited higher structural modes in the building. Since vertical bridges are flexible in the...

PEER Hub ImageNet (ϕ - Net): A Large-Scale Multi-Attribute Benchmark Dataset of Structural Images, PEER Report 2019/07

Yuqing Gao
Khalid M. Mosalam

In this data explosion epoch, data-driven structural health monitoring (SHM) and rapid damage assessment after natural hazards have become of great interest in civil engineering research. This report introduces deep-learning (DL) approaches and their application to structural engineering, such as post-disaster structural reconnaissance and vision-based SHM. Using DL in vision-based SHM is a relatively new research direction in civil engineering. As researchers begin to apply these concepts to structural engineering concerns, two critical issues remain to be addressed: (1) the lack of a...

Fluid-Structure Interaction and Python-Scripting Capabilities in OpenSees, PEER Report 2019/06

Minjie Zhu
Michael H. Scott

Building upon recent advances in OpenSees, the goals of this project are to expand the framework’s Python scripting capabilities and to further develop its fluid–structure interaction (FSI) simulation capabilities, which are based on the particle finite-element method (PFEM). At its inception, the FSI modules in OpenSees were based on Python scripting. To accomplish FSI simulations in OpenSees, Python commands have been added for a limited number of pre-existing element and material commands, e.g., linear-elastic triangle elements and beam–column elements with Concrete01/Steel01 fiber...

Expected Earthquake Performance of Buildings Designed to the California Building Code (brochure), PEER Report 2019/05, (California Alfred E. Alquist Seismic Safety Commission Publication 19-01)

Grace S. Kang
Sifat Muin
Jorge Archbold
Bitanoosh Woods
Khalid Mosalam

The brochure explains the intent of the California Building Code, the expected performance of code-compliant new buildings when they are subjected to moderate and large earthquakes, possible consequences to residents, businesses, and communities, and initial proactive actions that can be taken.

“This publication combines information from the earthquake engineering community as well as policy and community officials, and it incorporates input from SSC’s commissioners and staff, whose valuable feedback reflected their diverse range of expertise and experience,” said Grace Kang, PEER...

Aftershock Seismic Vulnerability and Time-Dependent Risk Assessment of Bridges, PEER Report 2019/04

Sujith Mangalathu
Mehrdad Shokrabadi
Henry V. Burton

The time-dependent seismic risk of bridges is assessed while account accounting for the effect of aftershocks and the uncertainty in the damage state after a mainshock event. To achieve this, a Markov risk-assessment framework is adopted to account for the probabilistic transition of the bridge structure through different damage states and time-dependent aftershock hazard. The methodology is applied to three typical California bridge configurations that differ only based on their era of design and construction. Era 11, Era 22, and Era 33 designations are used for the three bridges, which...

Ground-Motion Directivity Modeling for Seismic Hazard Applications, PEER 2019/03

Jennifer L. Donahue
Jonathan P. Stewart
Nicolas Gregor
Yousef Bozorgnia

We reviewed five models for modifying the natural log mean and within-event standard deviation of ground-motion models (GMMs) to account for directivity effects in the near-fault environment. We found broad consistency for strike–slip ruptures, with positive and negative directivity effects for cases of rupture towards and away from a site of interest, respectively. We found substantial divergence among directivity models for reverse slip, with some providing maximum directivity for sites positioned to experience the peak alignment of rupture direction with the fault-slip direction (this...

Direct-Finite-Element Method for Nonlinear Earthquake Analysis of Concrete Dams Including Dam–Water–Foundation Rock Interaction, PEER Report 2019/02

Arnkjell Løkke
Anil Chopra

Evaluating the seismic performance of concrete dams requires nonlinear dynamic analysis of two- or three-dimensional dam–water–foundation rock systems that include all the factors known to be significant in the earthquake response of dams. Such analyses are greatly complicated by interaction between the structure, the impounded reservoir and the deformable foundation rock that supports it, and the fact that the fluid and foundation domains extend to large distances. Presented in this report is the development of a direct finite-element (FE) method for nonlinear earthquake analysis of two-...