地铁深基坑施工对邻近隧道的变形影响分析

Analysis on Influence of Subway Deep Foundation Pit Construction on Deformation of Adjacent Tunnels

摘要:

为研究地铁深基坑邻近隧道施工时既有隧道的受力与变形特性，以南京地铁9号线管子桥站基坑工程为背景，通过三维有限元分析，研究基坑开挖引起的既有隧道的受力与变形特性，计算结果表明：地铁基坑开挖引起的既有隧道最大沉降值为7.32 mm，最大水平位移为5.74 mm，隧道变形满足相关规范要求；隧道主体沿Y方向和Z方向产生的位移远大于沿X方向产生的位移；基坑开挖时，隧道敞开段与暗埋段会产生沉降差异，施工时应采取相应措施控制沉降差。

Abstract:

In order to study the stress and deformation characteristics of the existing tunnel during the construction of the subway deep foundation pit adjacent to the tunnel, taking the foundation pit project of Guanziqiao Station of Nanjing Metro Line 9 as the background and through 3D finite element analysis, the stress and deformation characteristics of the existing tunnel caused by the excavation of foundation pit are studied. The calculation result shows that the maximum settlement of the existing tunnel caused by the excavation of the subway foundation pit is 7.32 mm, and the maximum horizontal displacement is 5.74 mm. The tunnel deformation meets the requirements of relevant specifications. The displacement of the tunnel body along the Y and Z directions is much greater than that along the X direction. When the foundation pit is excavated, there will be a difference in settlement between the open section and the buried section of the tunnel. The corresponding measures should be taken to control the settlement difference during construction.