2008年汶川M_S8.0地震反应谱平台值衰减特性研究  

Attenuation characteristic of the response spectrum platform value for 2008 Wenchuan M_S8.0 earthquake

作　　者：万卫[1] 薄景山[1,2] 郭晓云[1] 

机构地区：[1]防灾科技学院,中国河北三河065201 [2]中国地震局工程力学研究所,中国哈尔滨150080

出　　处：《地震学报》2014年第6期1032-1042,1155,共11页Acta Seismologica Sinica

基　　金：中央高校基本科研业务费青年教师资助计划项目(ZY20140210);中央高校基本科研业务专项资金(ZY20120103)联合资助

摘　　要：2008年汶川MS8.0地震获得了大量的强震动记录,为研究反应谱特征参数衰减特性提供了重要的基础资料.本文对已知场地条件的174个台站的记录进行研究,计算其加速度反应谱并按照最小二乘分段拟合方法进行标定,进而拟合了反应谱平台值的衰减关系;对比分析了水平方向与竖直方向反应谱平台值的衰减特性,提出用"平台值的场地衰减影响系数"来定量研究不同场地类型对反应谱平台值的影响,用"衰减曲线下降速率"来定量分析不同衰减曲线的衰减速率.通过计算得出水平向Ⅰ,Ⅱ,Ⅲ类场地的平台值场地衰减影响系数平均值分别为0.535 8,1和1.579,且Ⅲ类场地的加速度平台值衰减曲线的衰减速率最小.After the 2008 Wenchuan Ms 8.0 earthquake,a large volume of strong motion records were acquired,which provides important basic data for the study on attenuation characteristics of seismic response spectrum parameters.This paper calculates the acceleration response spectra of strong motion records from 174 seismic stations with known site conditions.The spectra are calibrated via piecewise fitting with the least-squares method in order to fit the attenuation re-lationships of a response spectrum platform value.This paper also comparative-ly analyzes the attenuation characteristics of both vertical and horizontal re-sponse spectrum platform values so as to demonstrate how the quantitative study of site condition affects response spectrum platform values by means of the site attenuation influence coefficient of platform value.It also quantitatively analyzes the attenuation rates of different attenuation curves by means of their descending rates. The calculation results show that the site attenuation influence coefficients of horizontal platform value has an average value that is different for the three site types.The value for site type Ⅰ is 0.535 8,type Ⅱis 1;and type Ⅲ is 1.579,which is the minimum attenuation rate of the plat-form in all site types.

关 键 词：汶川地震 反应谱平台值 衰减关系 场地类型 

分 类 号：P315.9[天文地球—地震学]