含软弱土层的二维沉积盆地非线性地震反应分析  

Nonlinear seismic response analysis of two-dimensional sedimentary basin with weak interlayer

作　　者：温卫平[1,2] 陈树培 白克生 翟长海[1,2] WEN Weiping;CHEN Shupei;BAI Kesheng;ZHAI Changhai(Key Laboratory of Structures Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology,Harbin 150090,China;Key Laboratory of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,Harbin Institute of Technology,Harbin 150090,China)

机构地区：[1]哈尔滨工业大学结构工程灾变与控制教育部重点实验室,黑龙江哈尔滨150090 [2]哈尔滨工业大学土木工程智能防灾减灾工业与信息化部重点实验室,黑龙江哈尔滨150090

出　　处：《地震工程与工程振动》2022年第4期133-141,共9页Earthquake Engineering and Engineering Dynamics

基　　金：国家重点研发项目(2018YFC1504301)。

摘　　要：沉积盆地对地震动具有明显的放大作用,我国许多城市如北京、成都和西安等位于沉积盆地或盆地边缘场地上,因此研究地震作用下的盆地效应对于这些城市的城市规划、防震减灾等具有重要意义。真实盆地地质条件复杂,常含有软弱土层、子盆地和小山包等地质构造,以含有软弱土层的沉积盆地为研究对象,基于ABAQUS有限元数值计算软件建立了二维动力有限元模型,对模型在地震作用下的放大效应进行了研究。结果表明:在盆地的大部分区域,软弱表层土的存在均放大了盆地表面的PGA,随着软弱表层土厚度的增加,边缘区域和中心区域的PGA放大系数均呈先减小,再增大,随后再减小的趋势;软弱夹层大体上削弱了盆地的放大作用,随软弱夹层厚度增加,盆地边缘和中央区域的PGA先增大后减小;软弱夹层埋深增加,盆地边缘和中央区域的PGA呈减小趋势。且出现第一峰值下降,第二峰值增加的现象,这一现象在埋深为30 m和40 m时尤为突出。Sedimentary basins have significant amplifying effect on ground motions.Many cities in China,such as Beijing,Chengdu,and Xi'an,are located in sedimentary basins or on the edge of the basin.Therefore,studying the basin effect under earthquake is of great significance to the urban planning,earthquake prevention and disaster reduction of these cities.The geological conditions of real basins are complex,often containing soft soil layers,subbasins and other geological structures.In this paper,a two-dimensional dynamic finite element model was established based on ABAQUS,and the amplification effect of the model under earthquake excitation was studied.The results show that in most areas of the basin,the presence of soft topsoil layer amplifies the PGA of the basin.With the increase of the thickness of soft topsoil layer,the PGA amplification factor of the basin edge and central regions decrease first,then increase,and then decrease again.With the increase of the thickness of the soft interlayer,the PGA of the basin edge and the central region increases first and then decreases.With the increase of the depth of the soft interlayer,the PGA of the edge and central area of the basin shows a decreasing trend,and the value of the first peak decreases while the second peak value increases,which is particularly prominent when the depth of soft interlayer is 30 and 40 m.

关 键 词：盆地效应 软弱土层 地震反应 土的非线性本构模型 

分 类 号：TU435[建筑科学—岩土工程]