地铁车站狭长基坑支撑异常轴力分析  

Analysis of Abnormal Strut Axial Forces for Narrow and Long Deep Excavation of Metro Stations

作　　者：刘利国 罗家文 朱碧堂 Liu Liguo;Luo Jiawen;Zhu Bitang(China Railway No.4 Group Co.,Ltd.,Hefei 230023,China;School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China;Engineering R&D Centre for Underground Technology of Jiangxi Province,Nanchang 330013,China)

机构地区：[1]中铁四局集团有限公司,安徽合肥230023 [2]华东交通大学土木建筑学院,江西南昌330013 [3]江西省地下空间技术开发工程研究中心,江西南昌330013

出　　处：《华东交通大学学报》2024年第3期20-28,共9页Journal of East China Jiaotong University

基　　金：国家自然科学基金项目(52208343,52020105003)

摘　　要：【目的】研究地铁车站狭长型基坑施工过程中第一道支撑轴力过大的问题。【方法】通过土体小应变刚度硬化模型(HSS)有限元分析,对车站基坑土方的开挖方式、钢支撑安装质量差、钢支撑未及时受力等情况进行精细化模拟,分析其对第一道支撑轴力的影响。【结果】结果表明:采用盆式开挖对第一道支撑的轴力影响显著,相较分层开挖的情况增大45%,应及时安装对应位置的钢支撑;安装钢支撑的预应力未达到设计值时,会导致开挖到底时的顶层支撑轴力增大,增大幅度在10%以内,底层支撑轴力减小。【结论】在地铁车站狭长基坑开挖过程中应限制盆式超挖;温度变化对支撑轴力的影响不能忽视;安装下层钢支撑预应力达不到设计值时,会导致开挖到底时的顶部支撑轴力偏大。【Objective】The purpose of this paper is to address the issue of excessive axial force in the first support of a narrow and long deep excavation of metro stations during construction【.Method】Through the method of finite element analysis using the hardening soil model with small strain stiffness(HSS),the excavation method of the station pit,poor quality of steel support installation,and the untimely stressing of the steel support are simulated in a refined way to analyze the influence on the axial force of the first support.【Result】The results show that the use of basin excavation has a significant effect on the axial force of the first support,which increases by 45%compared with the case of layered excavation,and the corresponding position of the steel support should be installed in time;when the prestress of the installed steel support does not reach the design value,it will lead to an increase in the axial force of the top support at the end of the excavation,with an increase of 10%or less,and a decrease in the axial force of the bottom support.【Conclusion】Basin over-excavation should be strictly limited during excavation of narrow and long deep excavation of metro stations;The effect of temperature changes on support axial forces cannot be ignored;when the prestressing force of the installed lower steel support fails to reach the design value,it will lead to a large axial force of the top support at the bottom of excavation.

关 键 词：狭长型基坑 支撑轴力 土体小应变硬化模型 盆式开挖 

分 类 号：U231.4[交通运输工程—道路与铁道工程] TU52[建筑科学—建筑技术科学]