深厚覆盖层地区土层地震反应的不确定性分析  

Uncertainty analysis of seismic response of soil layer in deep overburden area

作　　者：叶迎晨 Ye Yingchen(Shanghai Yuchen Engineering Technology Co.,Ltd.,Shanghai 201108,China)

机构地区：[1]上海雨辰工程技术有限公司,上海201108

出　　处：《地震科学进展》2023年第5期193-202,共10页Progress in Earthquake Sciences

摘　　要：以上海地区作为深厚覆盖层地区代表,在丰富的地质资料基础上,全面、系统地分析了100 m以深地层的土层分布、剪切波速、土动力特性参数、密度和地震输入界面这5个不确定因素可能的分布范围,并采用逻辑树分析方法,利用等效线性化土层地震反应分析,计算得到了这5种不确定因素在23种工况下3个超越概率、4个典型地质孔的地表峰值加速度和反应谱结果。经分析表明,100 m以深地层的土动力特性参数、剪切波速、土层分布、密度属于低敏感性因素,其不确定性对地表地震动参数影响较小,峰值加速度差异基本在5%以内;地震输入界面属于高敏感性参数,对地表地震动参数(尤其是低频段)影响较大,最大差异可达30%—40%。地震安全性评价工作中应合理设定地震输入界面,以避免可能对工程抗震设防参数带来的不利影响。Taking Shanghai area as the representative of deep overburden area,based on abundant geological data,this paper comprehensively and systematically analyzes the possible distribution range of 5 uncertain factors,including soil layer distribution,shear wave velocity,soil dynamic characteristic parameters,density and seismic input interface,in a depth of 100 m,and uses the logic tree analysis method and equivalent linear method for seismic response analysis of soil layers,the surface peak acceleration and response spectrum results of 5 uncertain factors,3 exceedance probabilities and 4 typical geological holes under 23 working conditions are calculated.It shows that the parameters of soil dynamic characteristics,shear wave velocity,soil layer distribution and density in the depth of 100 m are low sensitive parameters,and their uncertainty have little impact on the ground motion parameters,the difference of peak acceleration are basically within 5%.The seismic input interface is a highly sensitive parameter,which has a great impact on the ground motion parameters(especially to the low frequency band),with the maximum difference of 30%—40%.The seismic input interface should be reasonably set in the seismic safety evaluation to avoid the adverse impact on the seismic fortification parameters of the project.

关 键 词：深厚覆盖层地区 深部地层不确定性 土层地震反应 地震动参数 

分 类 号：P315.9[天文地球—地震学]