四川固定强震台址场地效应反演研究  

Inversion Site Effects at Fixed Strong Motion Stations in Sichuan

作　　者：陈科霖 陈学良[2] CHEN Kelin;CHEN Xueliang(School of Civil Engineering,Guilin University of Technology,Guilin 541004,China;Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)

机构地区：[1]桂林理工大学土木工程学院,广西桂林541004 [2]中国地震局地球物理研究所,北京100081

出　　处：《灾害学》2024年第4期167-173,共7页Journal of Catastrophology

基　　金：国家自然科学基金面上项目“考虑宽频带地震动传播过程的汶川大地震场地液化非线性影响研究”(51978633)。

摘　　要：区域地震灾害分析是基于对控制地震地面运动的三个关键因素:震源、传播路径和场地条件的深入了解。这些因素可以借助广义反演技术(Generalized Inversion Technique,GIT),通过强震动记录的频谱分解来单独分析。该文使用完全参数化GIT,对2007—2020年四川地区发生的397次地震(3~6.5级)的3338组强震数据进行反演。针对区域场地效应,考虑基岩裂隙或风化作用的影响,确定了四川地区129个固定强震台址的场地放大系数。在介质衰减效应方面,区域几何衰减平均水平被确定为R^(-0.6),S波平均品质因子为150.33f^(0.78)。对于震源参数,区域应力降均值水平为9.25 MPa。该文结果可以为地震动建模或随机S波模拟提供合理的输入参数及数据,从而改进确定性地震危险性评估。Regional seismic hazard analysis is based on a deep understanding of the three key factors that control earthquake ground motion as source,propagation path and site conditions.These factors can be analyzed individually through the spectral decomposition of strong vibration records with the help of the Generalized Inversion Technique(GIT).By using fully parameterized GIT to invert 3338 sets of strong earthquake data from 397 earthquakes(magnitude 3 to 6.5)that occurred in Sichuan from 2007 to 2020.For regional site effects and taking into account the influence of bedrock fissures or weathering,the site amplification coefficients of 129 fixed strong earthquake stations in Sichuan are determined.For the medium attenuation parameters,the regional geometric attenuation average level is determined to be R^(-0.6),and the S-wave average quality factor is 150.33f^(0.78).For earthquake source parameters,the average regional stress drop level is 9.25 MPa.The results of this paper can provide reasonable input parameters and data for ground motion modeling or stochastic S-wave simulation,thereby improving deterministic seismic risk assessment.

关 键 词：广义反演技术 场地效应 应力降 品质因子Q 

分 类 号：X43[环境科学与工程—灾害防治] X915.5[天文地球—地震学] P315.6[天文地球—固体地球物理学]