区域性场地V_s30及峰值加速度放大系数估算方法  

Study on regional site V_s30 and PGA amplification factor

作　　者：史大成[1] 温瑞智[1] 杜春清[1,2] 

机构地区：[1]中国地震局工程力学研究所,黑龙江哈尔滨150080 [2]重庆市地震局,重庆401147

出　　处：《地震工程与工程振动》2012年第4期40-46,共7页Earthquake Engineering and Engineering Dynamics

基　　金：国际合作项目(2011DFA71100)

摘　　要：地震动速报评估方法中常常考虑场地的影响,为了提高地形坡度模型的区域性地表30m的平均剪切波速Vs30估算精度,本文提出了基于工程钻孔资料的Vs30的修正方法。通过计算实际钻孔的Vs30值与坡度模型估算的Vs30值之间的残差,分析了残差的空间变化趋势,利用克里金插值对所研究区域的Vs30残差趋势面进行插值,并与估算的Vs30进行空间叠加,实现了Vs30的修正。选取K-net和Kik-net台网中台站的剪切波速资料和强震记录回归了峰值加速度放大系数与场地Vs30的经验关系,将其应用于基于ShakeMap框架的地震动快速评估系统绘制了汶川地震影响区域的基岩和地表加速度峰值,分析场地条件对于地震动的实际影响,结果表明区域性场地Vs30及峰值加速度放大系数估算方法具有一定的适用性。The method of Vs30 estimation using topography slope data usually leads to great error. In this paper the relationship between slope and measured Vs30 is analyzed based on statistics and a correction method is given based on engineering boreholes data. On the basis of statistical Vs30 estimation model, the residual between the actually measured and estimated V30 is calculated to analyze the Vs30 residual spatial trends and the modified regional V30 is calculated by overlaying the regional V SO layer and residual trend layer. Using shear wave velocity data and re- cordings from K-net and Kik-net, linear regression model of PGA amplification factor is established. As an exam- ple, the modified PGA map of Wenchuan earthquake is calculated under the ShakeMap system to validate the effi- ciency of this method.

关 键 词：Vs30 坡度 残差 克里金插值 放大系数 

分 类 号：P315.9[天文地球—地震学]