基于修正随机有限断层法的沉积盆地地震动模拟  

Seismic Simulation of Sedimentary Basin Based on Modifiedstochastic Finite Fault Method

作　　者：刘中宪[1,2] 周健[2] 李程程 孟思博 LIU Zhongxian;ZHOU Jian;LI Chengcheng;MENG Sibo(Tianjin ChengJian University,Tianjin Key Laboratory of Soft Soil Properties and Engineering Environment,Tianjin 300384,China;Tianjin Urban Construction University,Tianjin 300384,China;Tianjin Key Laboratory of Civil Building Structure Protection and Reinforcement,Tianjin 300384,China)

机构地区：[1]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 [2]天津城建大学,天津300384 [3]天津市土木建筑结构防护与加固重点实验室,天津300384

出　　处：《防灾减灾工程学报》2023年第5期999-1008,共10页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金联合基金重点项目(U2139208);中国地震局地震工程与工程振动重点实验室重点专项(2020EEEVL0302);国家自然科学基金项目(52008287,51968015)资助。

摘　　要：基于随机有限断层法理论框架,采用间接边界元方法求解沉积盆地地震动放大效应,以此修正场地放大因子,发展了一种可考虑盆地效应的修正随机有限断层法。基于该方法,模拟了2021年2月13日日本M_(W)7.1海域地震中日本关东盆地地震反应,并与常规随机有限断层法及实测地震记录进行了对比。结果表明:与常规随机有限断层法相比,采用修正随机有限断层法模拟盆地地震动表现出更显著的空间变异性,盆地边缘地震动峰值加速度较常规方法放大了6.24倍,与实测地震记录吻合度更高;区域地震动峰值加速度空间分布整体特征与实测地震记录基本一致;相较于不考虑场地影响下的结果盆地内部分台站长周期下的谱加速度值扩大了近5倍,表明深厚沉积盆地在长周期范围内的场地放大更加明显。Through the indirect boundary element method,the amplitude amplification factor spectrum of each observation point on different sedimentary basins is obtained,and based on this,a random finite fault method ground motion simulation considering the influence of basin topography is proposed.Using this method,this research simulates and studies the seismic response of internal and external stations in Japan's Kanto basin to the M_(w)7.1 sea area earthquake in Japan on February 13,2021.It is found that the two simulation results will be quite different with and without topographic amplification.If only the amplification effect of soil layer is considered,the simulated peak acceleration of each station only decreases with the increase of epicentral distance.However,generally speaking,the difference between them is not obvious.After considering the influence of basin,such as edge effect and focusing effect,the difference in simulated peak acceleration of each station will be very different,in which CHB001 station is amplified by about 6.24 times.When comparing the measured records of the station with the simulated data,the results show good agreement.It indicates that when using the random finite fault method to simulate ground motion,the amplification effect of the site soil layer and the terrain of the observation point on the peak ground motion acceleration should be comprehensively considered,and the results obtained are more authentic.

关 键 词：间接边界元法 修正随机有限断层法 盆地效应 关东盆地 

分 类 号：P642.2[天文地球—工程地质学] TU43[天文地球—地质矿产勘探]