A5090024932- Seismic Performance and Analysis
- Seismic Waves and Analysis
- Geotechnical Engineering and Underground Structures
- Geotechnical Engineering and Soil Mechanics
- earthquake and tectonic studies
- Structural Health Monitoring Techniques
- Geotechnical Engineering and Soil Stabilization
- Landslides and related hazards
- Seismology and Earthquake Studies
- Geotechnical Engineering and Analysis
- Seismic Imaging and Inversion Techniques
- Dam Engineering and Safety
- Structural Engineering and Vibration Analysis
- Structural Response to Dynamic Loads
- Geophysics and Sensor Technology
- Earthquake Detection and Analysis
- Geophysical Methods and Applications
- Masonry and Concrete Structural Analysis
- Disaster Management and Resilience
- Geotechnical and construction materials studies
- Vibration and Dynamic Analysis
- Structural Analysis of Composite Materials
- High-pressure geophysics and materials
- Seismic and Structural Analysis of Tall Buildings
- Soil Mechanics and Vehicle Dynamics
University of California, Los Angeles
2016-2025
Samueli Institute
2024-2025
University of California, Berkeley
1995-2025
Southwest Research Institute
2023-2025
Geosyntec Consultants (United States)
2007-2025
Montana State University
2025
University of California System
2025
Dominion (United States)
2025
Old Dominion University
2023-2025
UCLA Health
2024
We provide ground motion prediction equations for computing medians and standard deviations of average horizontal component intensity measures (IMs) shallow crustal earthquakes in active tectonic regions. The were derived from a global database with M 3.0–7.9 events. the primary M- distance-dependence IMs after fixing V S30 -based nonlinear site term parallel NGA-West2 study. then evaluated additional effects using mixed residuals analysis, which revealed no trends source depth over range...
The NGA-West2 project database expands on its predecessor to include worldwide ground motion data recorded from shallow crustal earthquakes in active tectonic regimes post-2000 and a set of small-to-moderate-magnitude California between 1998 2011. includes 21,336 (mostly) three-component records 599 events. parameter space covered by the is M 3.0 7.9, closest distance 0.05 1,533 km, site time-averaged shear-wave velocity top 30 m V S30 = 94 m/s 2,100 (although becomes sparse for distances...
The NGA-West2 project is a large multidisciplinary, multi-year research program on the Next Generation Attenuation (NGA) models for shallow crustal earthquakes in active tectonic regions. has been coordinated by Pacific Earthquake Engineering Research Center (PEER), with extensive technical interactions among many individuals and organizations. addresses several key issues ground-motion seismic hazard, including updating NGA database magnitude range of 3.0–7.9; prediction equations (GMPEs)...
This paper presents a complete methodology for both probabilistic and deterministic assessment of seismic soil liquefaction triggering potential based on the cone penetration test (CPT). A comprehensive worldwide set CPT-based field case histories were compiled back analyzed, data then used to develop correlations. Issues investigated in this study include improved normalization CPT resistance measurements influence effective overburden stress, adjustment tip "thin" liquefiable layers. The...
Abstract A state‐of‐the‐art seismic performance assessment is illustrated through application to a reinforced‐concrete moment‐frame building designed per current (2003) code provisions. Performance quantified in terms of economic losses and collapse safety. The includes site‐specific hazard analyses, nonlinear dynamic structural response simulations collapse, damage loss estimation. When selecting ground motion records for analyses that are consistent with target level expressed spectral...
We analyze NGA-West2 data and simulations to develop a site amplification model that captures ground motion scaling with V S30 soil nonlinear effects. parameterize nonlinearity as the gradient of respect peak acceleration for reference (firm) sites. Both analyses indicate sites < 500 m/s spectral periods T ∼3 s. Following approximate removal effects from data, we evaluate -scaling motions, which is most pronounced ≥ ∼0.2 s saturates hard rock Regional trends in were not found be...
Commonly used simplified one-dimensional nonlinear seismic site response analyses employ constitutive models based on a variation of the hyperbolic model to represent initial stress-strain backbone curve. Desirable features curve include provision (1) an shear modulus at zero strain, (2) limiting stress large strains, and (3) flexible control behavior between those boundary conditions. Available have combinations two these features. A new general quadratic/hyperbolic (GQ/H) is developed from...
Recent improvements in seismological source modeling, analysis of travel path effects, and characterization local site effects on strong shaking have led to significant advances both code-based more advanced procedures for evaluating seismic demand structural design. A missing link, however, has been an improved empirically verified treatment soil-structure interaction (SSI) the motions transmitted structures response these motions. This paper describes system identification techniques...
For engineering systems having a potential for degradation under cyclic loading (e.g., landslides, soil profiles subject to liquefaction, some structural systems), the characterization of seismic demand should include amplitude and duration strong shaking within system. This article is concerned with significant-duration parameters, which are defined as time interval across specified amount energy dissipated (as measured by integral square ground acceleration or velocity). We develop...
System identification analyses are used to evaluate soil-structure interaction effects for 77 strong motion data sets at 57 building sites that encompass a wide range of structural and geotechnical conditions. Kinematic on the "input" bases structures found be relatively modest in many cases, whereas inertial response these motions can significant. To quantify effects, fixed- flexible-base modal vibration parameters first-mode period lengthening ratios T˜/T foundation damping factors ζ˜0....
One-dimensional nonlinear ground response analyses provide a more accurate characterization of the true soil behavior than equivalent-linear procedures, but application codes in practice has been limited, which results part from poorly documented and unclear parameter selection code usage protocols. In this article, exact (linear frequency-domain) solutions for body wave propagation through an elastic medium are used to establish guidelines two issues that have long source confusion users...
We develop empirical relationships to predict nonlinear (i.e., amplitude-dependant) amplification factors for 5% damped response spectral acceleration as a continuous function of average shear wave velocity in the upper 30 m, V s-30 . evaluate residuals between accelerations from recordings and modified rock attenuation active regions. Amplification at low- mid-periods is shown increase with decreasing exhibit nonlinearity that dependent on The degree large NEHRP Category E (V <180 m/s)...
Ground failure in Adapazari, Turkey during the 1999 Kocaeli earthquake was severe. Hundreds of structures settled, slid, tilted, and collapsed due part to liquefaction ground softening. more severe adjacent under buildings. The soils that led building damage were generally low plasticity silts. In this paper, results a comprehensive investigation which included cone penetration test (CPT) profiles followed by borings with standard tests (SPTs) soil index tests, are presented. effects...
A presentation of the model parameters and comparison median ground-motion values from NGA-West2 GMPEs is presented for a suite deterministic cases. In general, ground motions are similar, within factor about 1.5–2.0 5 < M 7 distances between 10–100 km. Differences increase (on order 2–3) large-magnitude (M > 8) earthquakes at large ( R 100–200 km) close 10 km). similar observed hanging-wall sites, slightly larger differences soil sites as opposed to rock sites. Regionalization four...
Ground motion prediction equations (GMPEs) relate ground intensity measures to variables describing earthquake source, path, and site effects. From many available GMPEs, we select those models recommended for use in seismic hazard assessments the Global Earthquake Model. We present a GMPE selection procedure that evaluates multidimensional trends (e.g., with respect magnitude, distance, structural period), examines functional forms, published quantitative tests of performance against...
Abstract Ground-motion prediction equations (GMPEs) have recently been developed in the Next Generation Attenuation (NGA) project for application to shallow crustal earthquakes tectonically active regions. We investigate compatibility of those models with respect magnitude scaling, distance and site scaling implied by Italian strong motion data. This is interest because (1) the data are principally from extensional regions that poorly represented NGA dataset, (2) past practice Italy has use...
Strong ground motions from the Mw=6.6 2007 Niigata-ken Chuetsu-oki earthquake were recorded by a free-field downhole array at nuclear power plant. Site conditions consist of about 70 m medium-dense sands overlying clayey bedrock, with groundwater located 45 m. Ground shaking bedrock level had geometric mean peak acceleration 0.55g, which reduced to 0.4g surface, indicating nonlinear site response. One-dimensional response analysis relatively weak motion aftershock data provides good matches...
We develop prediction equations for the median and standard deviation of significant duration earthquake ground motions from shallow crustal earthquakes in active tectonic regions. consider parameters 5–75%, 5–95%, 20–80% normalized Arias intensity. The were derived a global database with M 3.0–7.9 events. find noise effects on that compel us to exclude some records had been used previously models amplitude parameters. Our include an M-dependent source term also depends focal mechanism. At...
The NGA-West2 site database (SDB) contains information on condition and instrument housing for 4,147 strong-motion stations with recordings in the project flatfile. are from active tectonic regions, mainly California, Japan, Taiwan, China, Mediterranean area. principal parameter is time-averaged shear wave velocity upper 30 m ( V S30 ), which we characterize using measurements where available (2,013 stations) proxy-based relationships otherwise. We also provide basin depths published models...
This study investigates the conditions for which one-dimensional (1-D) nonlinear (NL) site response analysis results are distinct from equivalent-linear (EL) and provides guidance predicting when differences large enough to be of practical significance. Relative in spectral accelerations Fourier amplitudes computed NL EL analyses assessed a range suites input motions appropriate active crustal stable continental regions. Among several considered parameters, EL/NL most clearly dependent on...
Probabilistic seismic hazard analyses are usually performed with semi-empirical ground motion models (GMMs) following the ergodic assumption whereby average source, path, and site effects from global databases apply for a specific of interest. Site-specific response is likely to differ conditional on parameters used in GMMs (typically V S30 basin depth). Non-ergodic can be evaluated using on-site recordings and/or one-dimensional wave propagation analyses, allows site-to-site variability...
We present ground motion prediction equations (GMPEs) for computing natural log means and standard deviations of vertical-component intensity measures (IMs) shallow crustal earthquakes in active tectonic regions. The were derived from a global database with M 3.0–7.9 events. functions are similar to those our horizontal GMPEs. derive the primary M- distance-dependence peak acceleration, velocity, 5%-damped pseudo-spectral accelerations at oscillator periods between 0.01–10 s. observe...
This article documents the earthquake ground motion database developed for NGA-East Project, initiated as part of Next Generation Attenuation (NGA) research program and led by Pacific Earthquake Engineering Research Center (PEER). The project was focused on developing a characterization model (GMC) horizontal motions large region referred to Central Eastern North America (CENA). CENA covers most U.S. Canada, from Rocky Mountains Atlantic Ocean is characterized tectonically stable continental...