Development of attenuation relation for the near fault ground motion from the characteristic earthquake

作     者：史保平 刘博研 张健 

作者机构：Graduate University of Chinese Academy of Sciences 

出 版 物：《Acta Seismologica Sinica(English Edition)》 (ACTA SEISMOLOGICA SINICA)

年 卷 期：2007年第20卷第4期

页      面：416-424页

核心收录：

学科分类：070801[理学-固体地球物理学] 07[理学] 0707[理学-海洋科学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0815[工学-水利工程] 0813[工学-建筑学] 0814[工学-土木工程] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 

基　　金：One Hundred Individual Program of Chinese Academy of Sciences and National Natural Science Foundation of China (40574022) 

主　　题：rupture directivity ground motion peak ground acceleration 

摘      要：A composite source model has been used to simulate a broadband strong ground motion with an associated fault rupture process. A scenario earthquake fault model has been used to generate 1 000 earthquake events with a magni- tude of MwS.0. The simulated results show that, for the characteristic event with a strike-slip faulting, the character- istics of near fault ground motion is strongly dependent on the rupture directivity. If the distance between the sites and fault was given, the ground motion in the forward direction （Site A） is much larger than that in the backward direction （Site C） and that close to the fault （Site B）. The SH waves radiated from the fault, which corresponds to the fault-normal component plays a key role in the ground motion amplification. Corresponding to the sites A, B, and C, the statistical analysis shows that the ratio of their aPG is 2.15：1.5：1 and their standard deviations are about 0.12, 0.11 and 0.13, respectively. If these results are applied in the current probabilistic seismic hazard analysis （PSHA）, then, for the lower annual frequency of exceedance of peak ground acceleration, the predicted aPG from the hazard curve could reduce by 30% or more compared with the current PSHA model used in the developing of seismic hazard map in the USA. Therefore, with a consideration of near fault ground motion caused by the rupture directivity, the re- gression model used in the development of the regional attenuation relation should be modified accordingly.