基于合成地震动的2014年鲁甸Ms6.5地震场地效应分析

摘要

鲁甸Ms6.5地震造成了严重的人员伤亡与工程结构破坏,选取记录到该地震强震动的迤车强震台和龙头山强震台.利用随机有限断层法,合成了这2个台的地震动时程,并利用土层等效线性化法,分析了龙头山强震台的场地效应.结果表明,龙头山强震台场地存在较强的非线性效应,对0.08～5 s周期范围内的地震动存在较强的放大作用.结合龙头山镇的建筑物与场地情况,分析认为地震动的场地效应是造成该区域严重震害的重要原因之一.%Ludian earthquake caused serious casualties and structural damages.The maximum peak acceleration of Longtoushan site reaches 948.5 gal and its is about 4.4 km far from the epicenter.We choose Longtoushan site and Yiche site as target stations to simulate ground motion by using stochastic finite fault method.Based on synthetic ground motion,we also analyzed the site effect of Longtoushan station in the earthquake.The result shows that there was a site soil nonlinear behavior in Longtoushan site.Besides,there was a strong amplification of ground motion in the period of 0.08 ～ 5 s.In further discussion,we analyzed the site factors,which caused much more damage in the Ludian earthquake.