A Parametric Statistical Generalization of Uniform-Hazard Earthquake Ground Motions
Sets of ground motion records used for seismic hazard analyses typically have intensity measures corresponding to a particular hazard level for a site (perhaps conditioned on a particular intensity value and hazard). In many cases the number of available ground motions that match required spectral ordinates and other criteria (such as duration, fault rupture characteristics, and epicentral distance) may not be sufficient for high-resolution seismic hazard analysis. In such cases it is advantageous to generate additional ground motions using a parameterized statistical model calibrated to records of the smaller data set. This study presents a statistical parametric analysis of ground motion data sets that are classified according a seismic hazard level and a geographic region, and which have been used extensively for structural response and seismic hazard analyses. Parameters represent near-fault effects such as pulse velocity and pulse period, far field effects such as velocity amplitude and power spectral attributes, and envelope characteristics. A systematic fitting of parameterized pulse functions to the individual ground motion records, of parameterized envelopes to individual instantaneous ground motion amplitudes, and of parameterized power spectral density functions to averaged power spectra result in probability distributions for ground motion parameters representative of particular seismic hazard levels for specific geographical regions. This methodology presents a means to characterize the variability in a set of ground motions records in terms of physically meaningful parameters.
National Science Foundation
This material is based upon work supported by the the Civilian Research and Development Foundation for the Independent States of the Former Soviet Union (CRDF) under Award No. MG1-2319-CH-02 and by the National Science Foundation under Grant No. NSF-CMMI-0704959 (NEES Research), and Grant No. NSF-CMS-0402490 (NEES Operations). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
Dickinson, Bryce W., and Gavin, Henri P., "Generation of uniform-hazard earthquake ground motions," Journal of Structural Engineering, Submitted 30 June 2008; accepted 26 September 2010; posted ahead of print 21 October 2010
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