基于有限断层动力学模型的逆断层—三维层状沉积盆地地震动模拟  

Simulation of ground motions of a three-dimensional layered sedimentary basin near a reverse fault based on dynamic seismic-source model

作　　者：孟思博 金威 苗岳云 刘中宪[4] MENG Sibo;JIN Wei;MIAO Yueyun;LIU Zhongxian(Tianjin Key Laboratory of Structural Protection and Reinforcement,Tianjin Chengjian University,Tianjin 300384,China;Department of Logistics Surrporting,Logistics University of Chinese People’s Armed Police Force,Tianjin 300309,China;China Railway Shanghai Design Institute Group Co.,LTD.Tianjin Branch,Tianjin 300073,China;Tianjin Key Laboratory of Soft Soil Characteristics and Engineering Environment,Tianjin Chengjian University,Tianjin 300384,China)

机构地区：[1]天津城建大学天津市土木建筑结构防护与加固重点实验室,天津300384 [2]中国人民武装警察部队后勤学院后勤保障系,天津300309 [3]中铁上海设计院集团有限公司天津分院,天津300073 [4]天津城建大学天津市软土特性与工程环境重点实验室,天津300384

出　　处：《世界地震工程》2023年第2期158-166,共9页World Earthquake Engineering

基　　金：天津市科技支撑计划(19YFZCSN01180);中国地震局工程力学研究所基本科研业务费专项资助项目(2020EEEVL0302);天津市项目加团队项目共同支持。

摘　　要：近断层效应使得沉积盆地对地震动放大效应更为复杂。本文针对逆断层发震下三维层状沉积盆地地震反应,基于波动谱元法,采用有限断层动力学模型,模拟断层动力破裂、地壳层地震波传播和层状沉积盆地对地震波散射全过程。在此基础上,对比分析了层状和均质沉积盆地对近断层地震动放大效应的影响,讨论了不同断层倾角下层状沉积盆地地震动加速度特性。结果表明:层状沉积盆地PGA空间分布与均质沉积盆地存在较大差异,由于近断层效应和盆地效应,层状沉积盆地地表局部范围竖向PGA大于水平向PGA;90°断层倾角下层状沉积盆地地表地震动放大范围与60°断层倾角结果明显不同,主要集中在盆地中心区域和断层附近,且幅值远小于60°断层倾角下结果;沿断层走向,盆地内地表地震动加速度峰值对应时刻较盆地外延后。The rupture of reverse fault releases huge energy,which has a serious impact on wide areas and produces strong ground motions,and meanwhile the local sedimentary basin is of a significant amplification effect on ground motions,which will increase earthquake damage significantly.In order to investigate the reverse fault-three-dimensional layered sedimentary basin system based on the spectral element method,this paper has used a dynamic seismic-source model to study the process of fault rupture,seismic wave propagation,and seismic wave scattering in a layered sedimentary basin.The results are analyzed,including the influence of basins on seismic wave propagation,the time-frequency characteristics of ground motions with different fault dip angles.The results show that the horizontal peak ground acceleration(PGA)of homogeneous sedimentary basins is larger than that of layered sedimentary basins,and the vertical PGA is smaller than that of layered sedimentary basins,the distribution of peak ground velocity on the surface of layered sedimentary basins is quite different,and local amplification occurs.Besides,the hanging wall effect and the attenuation rate of ground vibration decreases as the dip angle of the fault increases.

关 键 词：层状沉积盆地 动力学震源模型 谱元法 断层倾角 

分 类 号：P315.31[天文地球—地震学]