Author(s): Kayen, RE; Gori, S; Lingwall, B; Galadini, F; Falcucci, E; Franke, K; Stewart, JP; Zimmaro, P | Abstract: Between August and November 2016, three major earthquake events occurred in Central Italy. The first event, with M6.1,... more
Author(s): Kayen, RE; Gori, S; Lingwall, B; Galadini, F; Falcucci, E; Franke, K; Stewart, JP; Zimmaro, P | Abstract: Between August and November 2016, three major earthquake events occurred in Central Italy. The first event, with M6.1, took place on 24 August 2016, the second (M5.9) on 26 October, and the third (M6.5) on 30 October 2016. As part of the Italy-US GEER team investigation, we recorded the amplitude and character of offset on the Mount Vettore Fault Zone (MVFZ) using traditional manual field recording and mapping techniques and advanced state-of-the-art geomatics methods of LIDAR and Structure From Motion. Extensive field surveys by INGV geologists and the GEER team were performed on the flanks of Mt Vettore after the 24 August and 30 October events, and a limited survey was done between the two October events by INGV. These surveys indicated normal offset on several strands of the MVFZ, along the upper flanks of Mount Vettore and on the Piano Grande basin floor. The pri...
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The V S30 parameter is by far the most widely used parameter that accounts for site conditions and site amplification in ground motion prediction equations (GMPEs). Albeit, V S30 , has been severely criticized for obvious pitfalls that... more
The V S30 parameter is by far the most widely used parameter that accounts for site conditions and site amplification in ground motion prediction equations (GMPEs). Albeit, V S30 , has been severely criticized for obvious pitfalls that might be misleading in site characterization, it still remains one of the most required parameters in seismic codes and major GMPEs. Direct measurements of seismic velocities to a depth of 30m consist the best way of obtaining the above parameter; however, it is rather often that no geophysical data are available, and thereof, V S30 should be estimated from proxies geology-based (Wills and Clahan, 2006) and ground slope-based (Wald and Allen, 2007). For this reason, a local profile database (PBD) has been elaborated, in order to establish local empirical correlations between surface geology and V S30 . In the present work, small scale (1:50,000) geologic and topographic maps have been used for Greece. The profile database (PBD) contains 314 sites, 238...
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Author: HENGESH, JV; LETTIS, WR; SAIKIA, CK; THIO, HK; ICHINOSE, GA; BODIN, P; POLET, J; SOMERVILLE, PG; NARULA, PL; CHAUBEY, SK; SINHA, S; CHANDRA, B; THAKKAR, SK; BASU, S; KUMAR, A; SHRIKHANDE, M; DAS, J; AGARWAL, P; BANSAL, MK;... more
Author: HENGESH, JV; LETTIS, WR; SAIKIA, CK; THIO, HK; ICHINOSE, GA; BODIN, P; POLET, J; SOMERVILLE, PG; NARULA, PL; CHAUBEY, SK; SINHA, S; CHANDRA, B; THAKKAR, SK; BASU, S; KUMAR, A; SHRIKHANDE, M; DAS, J; AGARWAL, P; BANSAL, MK; STEWART, JP; HOUGH, SE; VANDHANA, SV; MARTIN, S; TUTTLE, MP; TUCKER, KB; DEATON, SL; FROST, JD; BARDET, JP; RATHJE, EM; STEWART, J; DAYAL, U; HU, JP; NORRIS, G; PATIL, U; SINGH, JP; SEED, RB; MOSS, RES; HARDER, LF; MURTY, CVR; ...
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Research Interests: Civil Engineering, Seismic Hazard, Nonlinear dynamics, Performance Assessment, Earthquake, and 11 moreProbability Distribution & Applications, Earthquake Engineering and Structural Dynamics, Structural modelling, Coefficient of Variation, Building Design, Building Codes, Reinforced concrete, Ground Motion, Economic Loss, Structural Response, and Probability Distribution
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Ground motion prediction equations (GMPEs) relate ground motion 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... more
Ground motion prediction equations (GMPEs) relate ground motion 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 in the Global Earthquake Model. We present a GMPE selection procedure that evaluates multidimensional ground motion trends (e.g., with respect to magnitude, distance, and structural period), examines functional forms, and evaluates published quantitative tests of GMPE performance against independent data. Our recommendations include: four models, based principally on simulations, for stable continental regions; three empirical models for interface and in-slab subduction zone events; and three empirical models for active shallow crustal regions. To approximately incorporate epistemic uncertainties, the selection process accounts for alternate representations of key GMPE attributes, such as the rate of distance attenuation, which are defen...
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Research Interests: Engineering, Civil Engineering, Structural Engineering, Seismic Hazard, Nonlinear dynamics, and 13 morePerformance Assessment, Earthquake, Probability Distribution & Applications, Earthquake Engineering and Structural Dynamics, Structural modelling, Coefficient of Variation, Building Design, Building Codes, Reinforced concrete, Ground Motion, Economic Loss, Structural Response, and Probability Distribution
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We present a Hellenic database of intensity measures from uniformly processed strong ground motion recordings, together with metadata on earthquake source attributes and recording site conditions. The database consists of information from... more
We present a Hellenic database of intensity measures from uniformly processed strong ground motion recordings, together with metadata on earthquake source attributes and recording site conditions. The database consists of information from 471 earthquakes between 1973 and 2015 that produced 2993 usable recordings from 333 sites. A key element of this work is a unified presentation of data from two major data providers that operate in Greece (Institute of Engineering Seismology and Earthquake Engineering and the Institute of Geodynamics, National Observatory of Athens) along with a university-operated local urban array (University of Patras). Consistent procedures were applied to develop source parameters that include hypocenter locations, moment magnitudes (directly estimated or derived using a conversion procedure), fault-plane solutions, and finite-fault parameters (generally, for events with M>6.0). The time-averaged shear-wave velocity in the upper 30 m parameter is provided f...
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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 earthquakes in... more
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 earthquakes in California between 1998 and 2011. The database includes 21,336 (mostly) three-component records from 599 events. The parameter space covered by the database is M 3.0 to M 7.9, closest distance of 0.05 to 1,533 km, and site time-averaged shear-wave velocity in the top 30 m of V S30 = 94 m/s to 2,100 m/s (although data becomes sparse for distances >400 km and V S30 > 1,200 m/s or <150 m/s). The database includes uniformly processed time series and response spectral ordinates for 111 periods ranging from 0.01 s to 20 s at 11 damping ratios. Ground motions and metadata for source, path, and site conditions were subject to quality checks by ground motion prediction equation developers and topical working groups.
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INTRODUCTION This chapter provides an overview of the macroseismic effects of the Bhuj earthquake. Such information is useful for several reasons. First, direct information about the vulnerability of structures to strong ground motion is... more
INTRODUCTION This chapter provides an overview of the macroseismic effects of the Bhuj earthquake. Such information is useful for several reasons. First, direct information about the vulnerability of structures to strong ground motion is useful for assessing, and perhaps mitigating, the hazard posed to similar structures by future large earthquakes. Secondly, given the paucity of instrumental recordings of the Bhuj earthquake, macroseismic data can provide useful information about the spatial variation of ground motions. Finally, detailed damage assessments for this earthquake can be compared to available accounts of historic earthquakes in India and other similar tectonic regimes around the world. These comparisons will provide additional insight into the magnitude of important earthquakes for which there are few or no instrtmaental recordings. The Bhuj earthquake is of particular interest because of the possibility that it represents an analog for the principal New Madrid (central United States) earthquakes of 1811-1812. The Bhuj earthquake occurred much closer to an active plate boundary than did the New Madrid events, and the Bhuj earthquake might therefore be considered a plate boundary-related event. However, in both cases, the regions primarily affected by the earthquake are stable continental interiors with low attenuation. A quantification of damage patterns, such as that presented in this chapter, can provide useful insight into the attenuation and frequency content of ground motions, which may in turn be useful in resolving whether the Bhuj earthquake should be considered interplate or intraplate for the purpose of data classification. This chapter combines two different approaches to quantify macroseismic effects of the Bhuj earthquake. First, a large-scale map of intensities was compiled based on media accounts. Second, ground-level surveys of damage in towns and villages across the epicentral area by the India-U.S. Geotechnical Earthquake Engineering Reconnaissance Team were synthesized. This approach provides both coarseand fine-scale overviews of damage, as well as an opportunity to compare detailed ground-based intensity results to a "broad brush" intensity value determined from one or a small handful of media accounts for any one location.
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Similar maps were also presented by , , , , and so on. Even though some major disagreements exist among these experts, a consensus conclusion is that Degirmendere and the soccer field sites are located neither on the main or secondary... more
Similar maps were also presented by , , , , and so on. Even though some major disagreements exist among these experts, a consensus conclusion is that Degirmendere and the soccer field sites are located neither on the main or secondary fault traces nor on the normal fault ...
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The Mw 8.8 Maule, Chile, earthquake produced 31 usable strong motion recordings from currently accessible arrays over a rupture distance range of 30 to 700 km. Site conditions range from firm rock to soft soil but are most often competent... more
The Mw 8.8 Maule, Chile, earthquake produced 31 usable strong motion recordings from currently accessible arrays over a rupture distance range of 30 to 700 km. Site conditions range from firm rock to soft soil but are most often competent soil (NEHRP Category C or C/D). Most of the data were recorded on analogue instruments, which was digitized and processed with low- and high-cut filters designed to maximize the usable frequency range of the signals. The stations closest to the fault plane do not exhibit evidence of ground motion polarization from rupture directivity. Response spectra of nearby recordings on firm ground and soft soil indicate pronounced site effects, including several cases of resonance at site periods. A prior GMPE for interface subduction events captures well the distance scaling and dispersion of the data, but under-predicts the overall ground motion level, perhaps due to too-weak magnitude scaling.
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The Mw6.4 Achaia–Elia (Greece) earthquake on 8 June 2008 was a right-lateral strike-slip event on a nearly vertical faul. Moment tensor solutions coupled with geologic structure and aftershock distributions suggest a fault strike of... more
The Mw6.4 Achaia–Elia (Greece) earthquake on 8 June 2008 was a right-lateral strike-slip event on a nearly vertical faul. Moment tensor solutions coupled with geologic structure and aftershock distributions suggest a fault strike of approximately 210° on a previously unmapped fault. Rupture appears to have been concentrated over a 10–25 km depth range and did not break the surface. The northern rupture limit appears to correspond to a NW-striking normal fault near the Kato Achaia coastline. The mainshock was recorded by 27 accelerometers at distances from the surface projection of the fault ranging from approximately 15 to 350 km. The data demonstrate faster distance attenuation than predicted by contemporary Greek ground motion prediction equations (GMPEs). On the other hand, an NGA GMPE generally captures the distance attenuation but shows underprediction bias at short and long periods. Despite the presence of a range of site conditions at recording stations in the city of Patras,...
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The 2009 L'Aquila earthquake sequence includes the April 6 Mw 6.3 main shock and triggered events on April 7 and 9, each recorded on a digital network having five stations on the hanging wall of the main shock fault. We describe a... more
The 2009 L'Aquila earthquake sequence includes the April 6 Mw 6.3 main shock and triggered events on April 7 and 9, each recorded on a digital network having five stations on the hanging wall of the main shock fault. We describe a geometric source model drawing upon inversions by others. We describe record-specific ground motion data processing that includes the incorporation of static displacements of up to 13 cm (downdrop of hanging wall). The resulting database includes 47, 38, and 31 corrected triaxial recordings from the April 6, 7, and 9 events, respectively. We present site conditions for recording stations, including recent surface wave and borehole geophysics. We demonstrate that the high-frequency data are weaker than expected for normal fault earthquakes of these magnitudes and that the data attenuate with distance at rates generally consistent with modified next generation attenuation (NGA) equations for Italy that were available prior to the event.
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Blind predictions of ground response at the Turkey Flat vertical array site during the 2004 Parkfield earthquake were performed using a series of nonlinear and equivalent-linear ground-response analysis codes. In this article, we report... more
Blind predictions of ground response at the Turkey Flat vertical array site during the 2004 Parkfield earthquake were performed using a series of nonlinear and equivalent-linear ground-response analysis codes. In this article, we report the outcome of the blind predictions, compare the ...
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A field investigation was carried out to retest liquefaction and nonliquefaction sites from the 1976 Tangshan earthquake in the People's Republic of China (PRC). These sites were carefully investigated in 1978/1979 using standard... more
A field investigation was carried out to retest liquefaction and nonliquefaction sites from the 1976 Tangshan earthquake in the People's Republic of China (PRC). These sites were carefully investigated in 1978/1979 using standard penetration test (SPT) and cone penetration test (CPT) ...
Abstract The Multidisciplinary Center for Earthquake Engineering Research and National Science Foundation, in collaboration with the City of Los Angeles Department of Water and Power (LADWP), coordinated a controlled study of the use of... more
Abstract The Multidisciplinary Center for Earthquake Engineering Research and National Science Foundation, in collaboration with the City of Los Angeles Department of Water and Power (LADWP), coordinated a controlled study of the use of pulse-based terrestrial lidar ...
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Abstract We present the results from a controlled study on the use of pulse-based terrestrial lidar and phase-based airborne lidar to detect topographic change and ground deformation in areas of earthquake-and storm-induced landslides.... more
Abstract We present the results from a controlled study on the use of pulse-based terrestrial lidar and phase-based airborne lidar to detect topographic change and ground deformation in areas of earthquake-and storm-induced landslides. Terrestrial and airborne lidar scans ...
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Soil-structure interaction can affect the response of buildings with subterranean levels by modifying the characteristics of input motions relative to those in the free-field and through the added system compliance associated with... more
Soil-structure interaction can affect the response of buildings with subterranean levels by modifying the characteristics of input motions relative to those in the free-field and through the added system compliance associated with relative foundation/free-field translation and rocking. While ...
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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. The research project has been coordinated by the... more
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. The research project has been coordinated by the Pacific Earthquake Engineering Research Center (PEER), with extensive technical interactions among many individuals and organizations. NGA-West2 addresses several key issues in ground-motion seismic hazard, including updating the NGA database for a magnitude range of 3.0–7.9; updating NGA ground-motion prediction equations (GMPEs) for the “average” horizontal component; scaling response spectra for damping values other than 5%; quantifying the effects of directivity and directionality for horizontal ground motion; resolving discrepancies between the NGA and the National Earthquake Hazards Reduction Program (NEHRP) site amplification factors; analysis of epistemic uncertainty for NGA GMPEs; and developing GMPEs for vertical ground motion. This paper p...
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SUMMARY Ground motion prediction equations and seismic hazard analyses are used to evaluate design-basis ground motions that apply to a free-field and ground surface condition. In this paper, we address the manner by which those motions... more
SUMMARY Ground motion prediction equations and seismic hazard analyses are used to evaluate design-basis ground motions that apply to a free-field and ground surface condition. In this paper, we address the manner by which those motions can be utilized for the analysis ...