地下大空间结构地震响应规律研究  

Study on Seismic Response of Underground Large Space Structure

作　　者：瞿天亮 孟啸 李广帆 Qu Tianliang;Meng Xiao;Li Guangfan(China Railway Construction Group Co.,Ltd.,Beijing 100040,China;Faculty of Architecture,Civil and Transportation Engineering,Bejjing University of Technology,100124,China)

机构地区：[1]中铁建设集团有限公司,北京100040 [2]北京工业大学城市建设学部,100124

出　　处：《特种结构》2022年第3期97-103,共7页Special Structures

摘　　要：以北京某交通枢纽工程实际为背景,根据已有的勘察资料和现行规范,选取关键结构断面,计算该地下结构在多遇地震E1、设防地震E2和罕遇地震E3等级下的抗震性能。采用大型有限元分析软件ABAQUS,考虑土体与混凝土的非线性以及土与结构接触非线性,研究该车站结构在实际场地条件下地下结构的层间位移和位移角反应特征以及结构关键部位的应力反应特征。研究表明:结构薄弱层位于底板边跨中点部位,受土体重力挤压所造成的,应力峰值为14MPa未超过底板的安全余度;侧墙在基岩输入加速度峰值PGA≤0.2g时由于刚度不变使得结构加速度峰值上下基本一致,当基岩输入加速度峰值PGA>0.2g时侧墙出现刚度退化和强度退化现象使得各楼层加速度峰值出现变化。结构层间位移角峰值符合规范规定的大震、中震和小震下位移角极限值范围,即满足结构“小震不坏,中震可修,大震不倒”的抗震原则。In this paper,a transportation hub project in Beijing is taking as the study object.According to the existing geotechnical survey and current specifications,the seismic performance of selected key sections of the underground structure under the frequent earthquake E1,design earthquake E2 and rare earthquake E3 key structural are calculated.Using the finite element analysis software ABAQUS,considering the nonlinearity of soil and concrete and the contact nonlinearity nonlinear contact between soil and structure,the interstory displacement,displacement angle response characteristics of the underground structure and the stress response of key parts of the structure are investigated under the real site conditions.The results show that:Due to the gravity extrusion of the soil,the weak layer of the structure is located at the midpoint of the side span of the bottom floor,and the stress peak is 14 MPa.However,it does not exceed the safety margin of the bottom floor.When the bedrock input PGA of is ≤0.2 g,the stiffness of the side wall is constant,so that the structural acceleration peak value is basically consistent.When the bedrock input PGA is greater than 0.2 g,the stiffness and strength degradation of the side wall occur,and the peak acceleration of each floor changes.The peak value of the interstory displacement angle of the structure conforms to the displacement angle limit range under severe,moderate and minor earthquakes stated in the specification,that is,no damage under minor earthquakes,repairable under moderate earthquakes,no collapse under severe earthquakes.

关 键 词：地下大空间结构 地震响应 抗震性能 

分 类 号：TU311.3[建筑科学—结构工程] TU93