精河M_(s)6.6地震近断层地震动模拟  

Simulation of Near-fault Ground Motion of Jinghe M_S6.6 Earthquake

作　　者：杨泽 盛俭 金显廷 周正华 喻烟[3] 李存柱 YANG Ze;SHENG Jian;JIN Xianting;ZHOU Zhenghua;YU Yan;LI Cunzhu(College of Transportation Science&Engineering,Nanjing Tech University,Nanjing 210009,China;Earthquake Precursor Animal and Plant Observatory of Songyuan City,Songyunn 138000,China;Institute of Crustal Stress,China Earthquake Administralion,Beijing 100085,China)

机构地区：[1]南京工业大学交通运输工程学院,江苏南京210009 [2]松原市地震前兆动植物观测站,吉林松原138000 [3]中国地震局地壳应力研究所,北京100085

出　　处：《防灾减灾工程学报》2020年第6期1024-1036,1052,共14页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家重点研发计划(2017YFC1500400);北京市科委重大科技专项(Z181100003918005);中交集团2017年度重大科研项目(2017-ZJKJ-08)资助。

摘　　要：近断层地震动具有幅值高、高频成分丰富等特点,对短周期结构威胁甚大。为模拟近断层地震动作用,以精河地震为例,利用基于地震烈度转换方法的地震动衰减关系和随机有限断层方法模拟主震在6个场点产生的地震动,分析不同方法估计的峰值加速度与加速度反应谱衰减特征;同时选取17个场点的地震动,分析断层上盘效应,从而更加合理地估计近断层地震动。结合精河M_(s)6.6地震的发震构造分析,确定库松木切克山前断裂的分支精河水文站断裂为该地震的发震断层。研究结果表明:①随机方法估计的PGA与+σ误差项衰减关系短轴估计的PGA接近,两者可能都比较接近实际PGA;相较于衰减关系法,基于有限断层模型的随机方法,优势在于能较好模拟近断层地震动特征;②近断层地震动受上盘效应影响显著,断层距相同的上下盘场点,上盘地震动明显大于下盘;③对于有历史地震及地震数据的地区,可以基于已有地震数据,使用多种方法联合估计地震动参数,为工程场地地震安评提供参考依据。The near-fault ground motion has the characteristics of high amplitude and rich high-frequency components,which poses a great threat to short-period structures.In order to simulate the nearfault ground motion,taking the Jinghe earthquake as an example,the attenuation relationship of ground motion based on the methods of intensity conversion and stochastic finite-fault was simulated at the 6 field points of the major earthquake.The characteristics of peak ground motion acceleration and acceleration response spectrum estimated by different methods were analyzed.At the same time,the ground motions at the 17 field points were selected to analyze the hanging wall effect.Therefore,it is more reasonable to estimate the near-fault ground motion.Combining with the seismogenic tectonic analysis on the Jinghe Ms6.6 earthquake,the fault of Jinghe hydrological station,a branch of the Kusongmuqike piedmont fault,was determined as the seismogenic fault of the Jinghe Ms6.6 earthquake.The research results show that:①The PGA estimated by the stochastic method is close to the result of the short-axis estimation of the attenuation relationship of error terms,and both are probably close to the actual PGA.Comparing with the method of attenuation relationship,the stochastic method based on the finite-fault model can better simulate the characteristics of near-fault ground motion.②The near-fault ground motion is significantly affected by the hanging wall effect,the ground motion of the hanging wall is obviously larger than that of the footwall at the same fault distance.③For regions with historical earthquakes and seismic data,based on the existing seismic data,multiple simulation methods can be used jointly to estimate the ground motion parameters,so as to provide a reference for the seismic safety evaluation of the project site.

关 键 词：地震动衰减关系 随机有限断层 上盘效应 近断层地震动 地震动参数估计 

分 类 号：P315.9[天文地球—地震学]