A5049971204- Seismic Performance and Analysis
- Structural Health Monitoring Techniques
- Seismic Waves and Analysis
- Geotechnical Engineering and Underground Structures
- Structural Behavior of Reinforced Concrete
- Structural Engineering and Vibration Analysis
- earthquake and tectonic studies
- Structural Response to Dynamic Loads
- Masonry and Concrete Structural Analysis
- Infrastructure Resilience and Vulnerability Analysis
- Offshore Engineering and Technologies
- Seismology and Earthquake Studies
- Marine and Offshore Engineering Studies
- Structural Integrity and Reliability Analysis
- Canadian Policy and Governance
- Dam Engineering and Safety
- Landslides and related hazards
United States Geological Survey
2011-2023
Cooper Union
2018-2023
Stanford University
2022
ORCID
2021
University of California, Berkeley
2011-2016
The US National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using new science on seismicity, fault ruptures, ground motions, and probabilistic techniques to produce a standard of practice public policy other engineering applications (defined return periods greater than ∼475 or less ∼10,000 years). Changes time-independent seismic hazard (both increases decreases compared previous NSHMs) are substantial because the model considers more data earthquake rupture forecasts...
According to the regulatory building codes in United States (e.g., 2010 California Building Code), at least two horizontal ground motion components are required for three-dimensional (3D) response history analysis (RHA) of structures. For sites within 5 km an active fault, these records should be rotated fault-normal/fault-parallel (FN/FP) directions, and RHAs performed separately (when FN then FP aligned with transverse direction structural axes). It is assumed that this approach will lead...
Summary This study develops a framework to evaluate ground motion selection and modification (GMSM) procedures. The context is probabilistic seismic demand analysis, where response history analyses of given structure, using motions determined by GMSM procedure, are performed in order estimate the hazard curve (SDHC) for structure at site. Currently, procedure evaluated this comparing several resulting estimates SDHC, each derived from different definition conditioning intensity measure (IM)....
When the response of a structure is influenced significantly by multiple vibration modes, seismic demands determined history analyses with ground motions selected to match single conditional mean spectrum (CMS) may be unconservative for several quantities. An existing solution this problem determine demand as maximum from CMSs. To reduce computational effort while maintaining accuracy and precision, we introduce an alternative engineering that based on simplified version generalized CMS,...
Summary Two existing, contemporary ground motion selection and modification procedures – (i) exact conditional spectrum (CS‐exact) (ii) generalized intensity measure (GCIM) are evaluated in their ability to accurately estimate seismic demand hazard curves (SDHCs) of a given structure at specified site. The amount effort involved implementing these compute single SDHC is studied, case study chosen where rigorous benchmark SDHCs can be determined for evaluation purposes. By comparing estimates...
Summary This study presents a novel approach for evaluating ground motion selection and modification (GMSM) procedures in the context of probabilistic seismic demand analysis. In essence, synthetic motions are employed to derive benchmark hazard curve (SDHC), any structure response quantity interest, establish causal relationship between GMSM procedure bias its resulting estimate SDHC. An example is presented illustrate how may be evaluated using motions. To demonstrate robustness proposed...
Summary This paper develops a procedure to select unscaled ground motions for estimating seismic demand hazard curves (SDHCs) in performance‐based earthquake engineering. Currently, SDHCs are estimated from probabilistic analysis, where several ensembles of selected and scaled user‐specified scalar conditioning intensity measure (IM). In contrast, the developed herein provides way single ensemble SDHC. context motions, proposed requires three inputs: (i) database (ii) I M , vector IMs...
This article develops a methodology for selecting, scaling, and orienting three orthogonal components of ground motion (GM) when conducting intensity-based assessments structures. Target spectra selecting multicomponent GMs are critically examined strategies hazard-consistent investigated. The Conditional Mean Spectrum–Uniform Hazard Spectrum (CMS-UHS) Composite is proposed as an alternative to several Spectra complex three-dimensional (3D) To ensure hazard consistency, should be selected...
Relatively little research has been conducted to systematically quantify the nationwide earthquake risk of gas pipelines in US; simultaneously, national guidance is limited for operators across country consistently evaluate their assets. Furthermore, many challenges and uncertainties exist a comprehensive seismic assessment pipelines. As first stage systematic assessment, we transmission conterminous US due strong ground shaking, including associated uncertainties. Specifically, integrate...
The earthquake engineering profession is increasingly utilizing nonlinear response history analyses (RHA) to evaluate seismic performance of existing structures and proposed designs new structures. One the main ingredients RHA a set ground motion records representing expected hazard environment for structure. When recorded motions do not exist (as case in central United States) or when high-intensity are needed San Francisco Los Angeles), from other tectonically similar regions need be...
The current practice for selecting bidirectional ground motions (GM pairs) to conduct nonlinear response history analysis (RHA) of multistory buildings is restricted those with a symmetric plan. To overcome such limitations, we propose GM pairs be consistent pair target spectra defined along the structural axes, enabling unique azimuth determined each pair. We develop two new spectra: (1) s-GCMS horizontal components and (2) CMS-UHS Composite Spectrum. Based on RHAs both unsymmetric plans,...
The need for US Geological Survey (USGS) National Seismic Hazard Models (NSHMs) to report estimates of epistemic uncertainties in the hazard (e.g. fractile curves) all forthcoming releases is increasing. With curves as potential new outputs from USGS 2023 NSHM, a simultaneous help end-users better understand these and clarify their uses. In this article, we address latter by (1) characterizing two updates NSHM (2014 California 2021 Hawaii), (2) illustrating variety downstream applications...
The earthquake engineering profession is increasingly utilizing nonlinear response history analyses (RHA) to evaluate seismic performance of existing structures and proposed designs new structures. One the main ingredients RHA a set ground-motion records representing expected hazard environment for structure. When recorded motions do not exist (as case central United States), or when high-intensity are needed San Francisco Los Angeles), ground from other tectonically similar regions need be...
According to regulatory building codes in United States (for example, 2010 California Building Code), at least two horizontal ground-motion components are required for three-dimensional (3D) response history analysis (RHA) of buildings. For sites within 5 km an active fault, these records should be rotated fault-normal/fault-parallel (FN/FP) directions, and RHA analyses performed separately (when FN then FP aligned with the transverse direction structural axes). It is assumed that this...
ABSTRACT How does an earthquake affect buried pipeline networks? It is well known that the seismic performance of pipelines depends on ground failures (GFs) as strong shaking (SGS), but it unclear how various types hazards should be collectively combined, existing methodologies tend to examine each separately. In this article, we develop a probability-based methodology consistently combine SGS with three GF (surface faulting, liquefaction, and landslide) for forecasting damage in networks...
Summary In this short communication, we respond to the comments made by Dr Brendon A. Bradley and provide additional context our paper under discussion.Copyright © 2015 John Wiley & Sons, Ltd.
Abstract An ensemble of bidirectional ground motions (GMs) is required as input for nonlinear response history analysis (RHA) complex 3D structures. In building codes, an GMs often developed from a given design spectrum, or target spectrum. the research literature, several spectra have been proposed such intensity‐based assessments. The present study aims to comprehensively evaluate different options developing select inputs RHAs structural systems. To achieve this goal, we conducted both...
Using the 2018 National Seismic Hazard Model and Bridge Inventory, an annualized earthquake loss (AEL) study was conducted for approximately 610,000 bridges in conterminous United States, quantifying both direct indirect economic losses. The typical AEL framework has been augmented with new replacement unit cost data bridge-specific parameters modifying default fragility curves. Earthquake hazard is defined using spectral acceleration curves that account location-specific soil conditions....
Although the gas pipeline infrastructure in United States is vulnerable to seismic hazards of (i) strong ground shaking, and (ii) failures induced by surface faulting, liquefaction, or landslides, limited national guidance exists for operators consistently evaluate earthquake response their pipelines. To provide additional information stakeholders establish more consistency at a scale, we attempt quantify risk transmission pipelines conterminous using metric such as average annual loss,...