考虑地震动衰减特性的西安市断层近场区域划分  

Scope division of near-fault ground motion for Xi’an city

作　　者：王启耀[1] 石章燃 高家庆 陆俊璋 WANG Qiyao;SHI Zhangran;GAO Jiaqing;LU Junzhang(Architectural Engineering Institute,Chang’an University,Xi’an 710061,China)

机构地区：[1]长安大学建筑工程学院,陕西西安710061

出　　处：《世界地震工程》2024年第2期148-155,共8页World Earthquake Engineering

基　　金：陕西省重点研发计划项目“大西安高烈度灾害地质环境条件下城市地下空间利用研究”(2021SF2-02)。

摘　　要：相较于普通远场地震动,近断层地震动破坏特性更为复杂,引发的危害也更为严重。西安市及周边地区存在多条大型正断层,对其城市建设规划隐患重大。本文以PEER(美国太平洋抗震研究中心)正断层地震动记录为主,使用参数标准化、均值化及汉宁窗平滑化等方法对地震动参数进行了处理,然后根据统计回归分析及最小二乘法线性拟合确定了近正断层地震动的临界断层距,并据此划分了西安近断层地震动区域范围。结果表明:西安周边正断层临界断层距在10~17 km之间,且水平振动的近断层区域范围总是稍大于竖向振动;从西安外环高速内近断层地震动区域划分结果可以看出,西安城区大部分为近断层地震动区域。研究结果可为西安地震小区划及抗震减灾提供一定的科学依据。Compared with ordinary far-field ground motion,near fault ground motion is close to the epicenter and may contain velocity pulses,which makes the damage characteristics of the near fault site more complex and the harm caused by more serious.Xi’an is located in the Weihe River Basin and the geological conditions are complex,there are many large Normal faults in Xi’an and its surrounding areas,which pose a major danger to its construction planning.Therefore,this paper takes the Xi’an site as the engineering background,and classifies the site conditions according to moment magnitude and shear wave velocity.Based on the positive fault ground motion records of PEER(Pacific Earthquake Engineering Research Center),the appropriate ground motion parameters were selected,and these parameters were processed by parameter standardization,averaging,and Hanning window smoothing.The critical fault distance of the near-positive fault site was obtained by statistical regression analysis and least squares linear fitting method of the processed data,and the range of the near-fault area of Xi’an was divided according to this classification method.The results show that the critical fault distance of the positive fault around Xi’an is between 10~17 km,and the near-field range of horizontal vibration is always slightly larger than that of vertical vibration.It can be seen from the results of the division of near-fault seismic areas in the outer ring expressway of Xi’an that most of the urban area of Xi’an is near-fault seismic area.The research results can provide a certain scientific basis for Xi’an earthquake zoning and earthquake mitigation.

关 键 词：近断层地震动 正断层 西安 汉宁窗平滑化 回归统计分析:临界断层距 

分 类 号：TU4[建筑科学—土工工程]