Near‐fault spatial variation in strong ground motion due to rupture directivity and hanging wall effects from the Chi‐Chi, Taiwan earthquake

摘要: Damaging earthquakes feature large variations in the spatial ground motion distribution mainly due to source complexity, radiation pattern, and site conditions. In this study, we tried capture hanging wall rupture directivity effects from 1999 Chi-Chi, Taiwan earthquake (Mw=7.6), which provides largest acceleration data set since strong-motion seismology studies began. First, event-specific attenuation relations of parameters for near-field, footwall sites were developed. Then an empirical model peak (PGA) was introduced get residuals obtained relationships. The new PGA on indicates 46% 50% higher values than predicted means over near-field distance ranges. Finally, a period-dependent spectral amplitude factor representing dip-slip faulting system developed using Somerville et al. model. proposed shows larger amplification result previous study. During Chi-Chi earthquake, maximum factors have been registered up-dip region, located around surface exposure Chelungpu fault, range 1.1 1.3 structural periods 0.6s 5.0s. Since derived residual function single event without any influence inter-event variability, is magnitude- distance-independent. Hence can be easily implemented into relations, seismic hazard assessment, building code revision regions with faulting. Copyright 2003 © John Wiley & Sons, Ltd.