摘要
基坑开挖卸荷可能会对周边既有地铁隧道产生影响,以某地铁线上方在建基坑工程为例,采用有限元分析方法结合现场实测结果对基坑内外地标沉降、隧道变形、应力变化等开展研究。研究结果表明,基坑开挖导致的应力重分布在一定程度上引起既有盾构隧道的变形,开挖卸荷引起隧道横截面发生微小变形。有限元计算结果显示,基坑范围外的土体由于开挖卸荷向坑内移动,墙后土体发生沉降,围护结构竖向范围两侧的土体竖向应力发生变化,而土体和地下连续墙的相对移动产生的摩擦力阻止了墙后隧道的向上移动,其结果是引起隧道的微小隆起。因此,在隧道周边进行施工时,除了对基坑本身进行监测,还需要对隧道结构加强监测。
The excavation and unloading of foundation pits will have an impact on the existing subway tunnel beneath it,finite element analysis method was used to combine on-site measurement results to study the settlement of landmarks inside and outside the foundation pit,tunnel deformation,stress changes,and other aspects of the under construction foundation pit project above a certain subway line.The research results indicate that stress redistribution caused by excavation of foundation pits causes deformation of existing shield tunnels to a certain extent,and excavation unloading causes slight deformation of the tunnel cross-section.The finite element calculation results show that the soil outside the excavation area moves towards the inside of the pit due to excavation unloading,causing settlement of the soil behind the wall.The vertical stress of the soil on both sides of the vertical range of the retaining structure changes,and the frictional force generated by the relative movement of the soil and the connecting wall prevents the upward movement of the tunnel behind the wall,resulting in a slight uplift of the tunnel.Therefore,during construction around the tunnel,in addition to monitoring the foundation pit itself,it is also necessary to strengthen monitoring of the tunnel structure.
作者
汤东婴
魏晓斌
孙正华
郭建祥
TANG Dong-ying;WEI Xiao-bin;SUN Zheng-hua;GUO Jian-xiang(Jiangsu Testing Center for Quality of Construction Engineering Co.,Ltd.,210033,Nanjing,China;Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,210098,Nanjing,China)
出处
《建筑技术》
2025年第8期988-993,共6页
Architecture Technology
基金
住房和城乡建设部科学技术计划项目(K20221278)。
关键词
基坑开挖
盾构隧道
数值模拟
变形分析
foundation pit excavation
shield tunnel
numerical simulation
deformation analysis
