某地铁车站深基坑围护结构的优化设计

Optimal Design of Retaining Structure of Deep Foundation Pit at a Metro Station

某地铁车站采取盖挖逆做法施工,由于区间线路纵坡调整,引起围护结构方案部分调整,取消车站标准段第4道混凝土支撑,在第3道混凝土支撑下架设斜撑。为探讨方案调整对围护结构内力和变形产生的影响,采用MIDASGEN有限元软件对地下连续墙、混凝土撑及斜撑的内力及变形进行分析及检算,得出地下连续墙、钢筋混凝土撑及斜撑的内力及变形均满足一级基坑的变形保护等级要求,达到优化设计、缩短工期及节省工程投资的目的。

A certain metro station is constructed by the method of top-down excavation.The retaining structure scheme had to partly change with the change of the profile grade of the section track.The fourth concrete bracing of the standard section had to be cancelled while the inclined struts had to be set under the third concrete bracing.In order to research the influences on the internal force and deformation of retaining structure caused by the change,the MIDAS GEN finite element software were adopted to analyze the internal force and deformation of the diaphragm wall,concrete bracing and the inclined struts.The analysis results showed that these internal force and deformation of retaining structure can all meet the requirements of deformation protection of Level I foundation pit,and so the aim of optimizing the design,shortening the construction period and saving the construction cost can be reached.