PEER Reports

PEER Reports

Flow-Failure Case History of the Las Palmas, Chile, Tailings Dam, PEER Report 2019/01

R. E. S. Moss
T. R. Gebhart
D. J. Frost
C. Ledezma
2019

This report documents the flow failure of the Las Palmas tailings dam that was induced by the 27 February 2010 Maule Chile M8.8 earthquake. The Las Palmas site is located in Central Chile in Region VII near the town of Talca. Construction of the tailings dam occurred between 1998 as part of a gold mining operation and was no longer in active use.

The ground shaking from the earthquake induced liquefaction of the saturated tailings material and resulted in a flow failure that ran out upwards of 350 m, flowing downslope in two directions. This report is broken into three sections:...

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
2019

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-...

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

Jennifer L. Donahue
Jonathan P. Stewart
Nicolas Gregor
Yousef Bozorgnia
2019

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...

Data Resources for NGA-Subduction Project, PEER Report 2020/02

Yousef Bozorgnia (NGA-Sub PI)
Jonathan P. Stewart (Editor)
2020

The NGA-Subduction (NGA-Sub) project is one in a series of Next Generation Attenuation (NGA) projects directed towards database and ground-motion model development for applications in seismic-demand characterization. Whereas prior projects had targeted shallow crustal earthquakes, active tectonic regions (NGA-West1 and NGA-West2), and stable continental regions (NGA-East), NGA-Sub is the first to address specifically subduction zones, which are a dominant source of seismic hazard in many regions globally, including the Pacific Northwest region of the United States and Canada.

This...

Effective Stress Analysis of Liquefaction Sites and Evaluation of Sediment Ejecta Potential, PEER Report 2021/03

Daniel Hutabarat
Jonathan D. Bray
2021

Sediment ejecta mechanism contributes significantly to the severity of liquefaction-induced ground failure (e.g., excessive land subsidence). Estimating the amount of ejected sediment is a key step to assess the severity of ground failure; however, procedures to quantify it are currently lacking. Sediment ejecta is a post-shaking phenomenon resulting from the migration and redistribution of excess-pore-water-pressure (ue) generated during earthquake shaking. The dissipation process of residual ue can trigger high-gradient upward seepage, which...

NGA-Subduction Global Ground-Motion Models with Regional Adjustment Factors, PEER Report 2020/03

Grace A. Parker
Jonathan P. Stewart
David M. Boore
Gail M. Atkinson
Behzad Hassani
2020

Next Generation Attenuation Subduction (NGA-Sub) is a multi-year, multidisciplinary project with the goal of developing an earthquake ground-motion database of processed time series and ground-motion intensity measures (IMs), as well as a suite of ground-motion models (GMMs) for global subduction zone earthquakes. The project considers interface and intraslab earthquakes that have occurred in Japan, Taiwan, New Zealand, Mexico, Central America, South America, Alaska, and Cascadia. This report describes one of the resulting GMMs, one important feature of which is its ability to describe...

Modeling Viscous Damping in Nonlinear Response History Analysis of Steel Moment-Frame Buildings: Design-Plus Ground Motions, Revision 1.0, PEER Report 2020/01

Xin Qian
Anil K. Chopra
Frank McKenna
2020

This report investigates the question: can seismic demands on steel moment-frame buildings due to Maximum Considered Earthquake (MCER) design-level ground motions [2% probability of exceedance (PE) in 50 years] be estimated satisfactorily using linear viscous damping models or is a nonlinear model, such as capped damping, necessary? This investigation employs two models of a 20-story steel moment-frame building: a simple model and an enhanced model with several complex features. Considered are two linear viscous damping models: Rayleigh damping and constant modal damping; and...

Conditional Ground-Motion Model for Peak Ground Velocity for Active Crustal Regions, PEER Report 2020/05

Norman A. Abrahamson
Sarabjot Bhasin
2020

Conditional models for the horizontal and vertical peak ground velocity (PGV), given the pseudospectral acceleration [PSA(T)] values, are developed for active crustal regions. The period of the PSA(T) used in the conditional model, TPGV , is magnitude dependent, which captures the effect of the magnitude dependence of the earthquake source corner frequency on the PGV. Conditional models can be used to estimate the PGV given a design spectrum and are applicable for magnitudes between 3.0 and 8.5, and for distances up to 200 km. The...

Partially Non-Ergodic Ground-Motion Model for Subduction Regions using the NGA Subduction Database, PEER Report 2020/04

Nicolas Kuehn
Yousef Bozorgnia
Kenneth W. Campbell
Nicholas Gregor
2020

This report presents a summary of the development, evaluation, and comparison of a new subduc-tion ground-motion model (GMM), now known as Kuehn-Bozorgnia-Campbell-Gregor (KBCG20) model. This GMM was developed as part of the Next Generation Attenuation for Subduction Regions (NGA-Sub) program using a comprehensive compilation of subduction interface and in-traslab ground-motion recordings and metadata compiled in the NGA-Sub database. The KBCG20 model includes ground-motion scaling terms for magnitude, distance, site amplification, and basin amplification. Some of these terms are adjustable...

Project Technical Summary (PEER-CEA Project), Peer Report 2020/12

Evan Reis
Yousef Bozorgnia
Henry Burton
Kelly Cobeen
Gregory G. Deierlein
Tara Hutchinson
Grace S. Kang
Bret Lizundia
Silvia Mazzoni
Sharyl Rabonivici
Brandon Schiller
David P. Welch
Farzin Zareian
2020

This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER-CEA Project.”

The overall objective of the PEER–CEA project is to provide scientifically based information (e.g., testing, analysis,...