非对称基坑开挖对邻近地铁隧道变形性分析

Analysis of Influence of Asymmetric Foundation Pit Excavation on Deformation of Adjacent Subway Tunnels

以沈阳市金廊深基坑工程为例,利用MIDAS/GTS有限元软件建立三维数值分析模型,对基坑开挖引起的隧道区间和地铁车站位移情况进行分析,并通过现场实测进行验证。结果表明:基坑开挖深度与地铁隧道埋深相近时,随着基坑开挖卸荷隧道区间结构整体上浮,越靠近基坑中心,上浮变形趋势越明显,但水平和竖向位移不大。基坑开挖会造成车站出入口朝基坑处发生水平位移和整体下沉,出入口扶梯位置上下端位移不明显。

Taking the Jinlang deep foundation pit project in Shenyang City as the background,MIDAS/GTS finite element software is used to establish a three-dimensional numerical analysis model to analyze the influence of the tunnel interval and subway station displacement caused by the foundation pit excavation,through the field test verification.The results show that when the excavation depth of the foundation pit is similar to the buried depth of the subway tunnel,the closer the foundation pit,the more obvious the uplifted deformation.But the horizontal and vertical displacement is not obvious.The foundation pit excavation can cause the horizontal displacement and overall subsidence of the station entrance and exit,with little difference in displacement between the upper and lower ends of the escalator at the entrance and exit.