新建地铁站基坑与既有车站结构间相互影响的数值分析

为解决新建地铁站基坑施工与临近既有车站结构间相互影响的问题,依托深圳地铁5号线前海湾站基坑工程和与其相邻的1号线鲤鱼门车站工程,采用FLAC3D有限差分软件,计算分析施工过程中前海湾站新基坑围护结构与鲤鱼门车站既有主体结构的受力变形情况。研究结果表明:既有鲤鱼门车站的存在对新基坑的开挖较为有利,可减小鲤鱼门站同侧的桩体变形(24.7%)和钢支撑轴力,使新基坑开挖更偏于安全;而新基坑开挖会使既有车站结构产生位移和一定转动,对既有车站的稳定和安全性影响较小。

Numerical Simulation on Interaction between New Foundation Pit and Existing Metro Station

The deformation of the retaining structure of the foundation pit of Qianhaiwan Station and that of the main structure of the existing Liyumen Metro Station are analyzed by means of FLAC3D finite element method,so as to minimize the interaction between the foundation pit construction and the existing Metro station.The study results show that the existing Liyumen station is favorable to the excavation of the new foundation pit because it can reduce the deformation of the piles on the same side by 24.7% and can reduce the axial force of the steel supports,which makes the excavation safer;on the other hand,the excavation of the new foundation pit will make the existing station rotate with a small value,which has little effect on the stability and safety of the existing station.