地铁隧道侧方基坑支护设计及变形控制

Support Design and Deformation Control of Side Foundation Pit of Metro Tunnel

地铁隧道侧方基坑开挖,必须严格控制基坑开挖对地铁线路的影响,确保既有地铁线路的正常运营。以深圳地铁9号线区间隧道结构侧方新建某基坑工程为背景,对邻近地铁隧道的基坑支护设计、施工方案及地铁隧道变形数值模拟结果进行分析总结。主要得出以下结论:(1)选择合理的基坑支护设计和施工方案对控制相邻地铁隧道结构的变形至关重要;(2)紧邻地铁隧道的基坑采用桩+环形撑的支护形式,在提高支护刚度的同时便于基坑开挖,阴角部位采用角撑支护,降低对地铁的影响;(3)通过变形数值模拟分析,地铁隧道变形满足规范要求,同时能确保基坑的安全。

When excavating a foundation pit on the side of a subway tunnel,the impact of the excavation on the subway lines must be strictly controlled to ensure the normal operation of the existing subway lines.Taking the construction of a new foundation pit on the side of the tunnel structure of Shenzhen Metro Line 9 as the background,the support design,construction scheme and numerical simulation results of subway tunnel deformation are summarized.The main conclusions are as follows:1)choosing a reasonable foundation pit support design and construction plan is crucial to control the deformation of the adjacent subway tunnel structure;2)the foundation pit adjacent to the side of the subway tunnel adopts a pile+ring brace support form,While improving the support stiffness,it is easy to excavate the foundation pit.The corners are supported by angle brackets to reduce the impact on the subway.3)Through the numerical simulation analysis of deformation,the deformation of the subway tunnel meets the requirements of the code and the safety of the foundation pit can be ensured.