基于谱元法的近场地震动空间相干性分析  

Spatial coherence analysis of near-field earthquake ground motion based on spectral element method

作　　者：袁安琪 丁海平[1] YUAN Anqi;DING Haiping(Jiangsu Key Laboratory of Structure Engineering,SUST,Suzhou 215011,China)

机构地区：[1]苏州科技大学江苏省结构工程重点实验室,江苏苏州215011

出　　处：《苏州科技大学学报（工程技术版）》2024年第2期1-7,共7页Journal of Suzhou University of Science and Technology（Engineering and Technology Edition）

基　　金：国家自然科学基金项目(51678383)。

摘　　要：由于专门用于地震动空间相关性研究的台阵强震记录偏少,基于强震记录统计回归的经验模型发展受限,采用谱元程序SPECFEM2D合成了不同震源机制引起的近场强地震动。通过对地震动场模拟结果进行地震动空间相关性分析,着重比较了不同的震中距对地震动空间相关性的影响,给出了不同震中距对应的相干函数,并得到如下结论:基岩地震动的相干性随震中距的增加而降低;震中距小于或等于15 km时的相干系数大于倾滑断层结果,震中距大于15 km时的相干系数小于倾滑断层结果,但均大于走滑断层结果;基于地震动模拟结果得到的相干性高于基于实测记录的统计结果。Due to the limited number of array strong earthquake records dedicated to the study of spatial correlation of ground motion,the development of empirical models based on statistical regression of strong earthquake records is limited.In this paper,the spectral element program SPECFEM2D is used to synthesize near field strong ground motions caused by different source mechanisms.Through the analysis of spatial correlation of ground motion on the simulation results of earthquake motion field,the corresponding coherence functions of different epicentral distance are given,and the conclusions are obtained in the following:firstly,the coherence of bedrock ground motion decreases with the increase of epicentral distance;secondly,when the Epicentral distance is less than 15km,the coherence coefficient is larger than that of dip slip fault,and when the Epicentral distance is greater than 15km,the coherence coefficient is smaller than that of dip slip fault,but both are smaller than that of strike slip fault;finally,the coherence obtained from the ground motion simulation results is higher than the statistical results based on the measured records.

关 键 词：地震动模拟 谱元法 震源机制 地震动相干性 震中距 

分 类 号：P315.9[天文地球—地震学]