地铁车站明挖深基坑支护结构稳定性分析

Stability analysis of support structure of open cutdeep foundation pit in subway station

以西安某地铁站明挖深基坑支护结构为背景,基于有限元分析对明挖深基坑支护结构进行稳定性分析。结果表明,深基坑开挖引起的地表竖向变形为-11.8^-10.2 mm,混凝土灌注桩顶侧向最大变形10.9 mm,符合西安地区湿陷性黄土地铁车站深基坑开挖引起的地表及基坑支护结构变形特性;在基坑开挖阶段,除第3道直撑外,内支撑轴力远小于设计值,存在较大的优化空间;内支撑结构安全可行,可为类似基坑的施工借鉴。

Based on the support structure of open cut deep foundation pit of a subway station in Xi'an,and with the finite element analysis,this paper analyzes the stability of the support structure of an open cut deep foundation pit.The results show that the ground surface vertical deformation caused by the excavation of deep foundation pit is between-11.8 mm and-10.2 mm,and the maximum lateral deformation of the top of concrete cast-in-place pile is 10.9 mm,which is consistent with the deformation characteristics of ground surface and foundation pit support system caused by deep foundation pit excavation in Xi'an collapsible loess subway station.In the stage of foundation pit excavation,the axial force of internal support is far less than the design value,and there is a big optimization space,while the internal support system is safe and feasible,providing reference for similar foundation pit construction.