某地铁车站深基坑开挖地连墙水平位移分析

现场监测难以预测基坑和围护结构后期变形规律。采用MIDAS/GTS NX对某地铁车站深基坑开挖及支护全过程进行数值模拟,探寻深基坑开挖引起的地连墙水平位移变化规律,并对比现场监测数据验证数据模拟的可靠性。研究结果表明:随着基坑的开挖,地连墙不同深度下的水平位移变化呈现出内凸的规律,开挖完成时模拟最大水平位移值约为11.6 mm,现场监测最大值约为13.9 mm,最大水平位移位于开挖面附近;改变地连墙厚度及嵌固深度后发现,地连墙厚度及嵌固深度的增大可减小地连墙深层水平位移,但对地连墙顶部水平位移影响较小。研究成果可为深基坑开挖对周边环境影响的分析及类似工程施工方案的优化提供参考。

Horizontal Displacement Analysis of Diaphragm Wall in Deep Foundation Pit Excavation of a Subway Station

It is difficult to predict the later deformation pattern of the foundation pit and envelop enclosure simply by on-site monitoring. In this paper, MIDAS/GTS NX was used to simulate the whole process of foundation pit excavation and support. As a result, the variation rule of horizontal displacement of diaphragm wall caused by deep foundation pit excavation was found, and the rationality of the simulation was verified by comparing the monitoring data. The results show that, with the excavation of the foundation pit, the horizontal displacement of the diaphragm wall at different depths shows an "inner convex" pattern. When the excavation is completed, the simulated maximum horizontal displacement is about 11.6 mm, the maximum value of on-site monitoring is about 13.9 mm, and the maximum horizontal displacement is located near the excavation surface;After changing the thickness and buried depth of the diaphragm wall, it is found that the increase of the thickness and embedded depth of the diaphragm wall can reduce its deep horizontal displacement, but has little effect on the top horizontal displacement. The research results can provide reference for the impact analysis of the deep foundation pit excavation on the surrounding and the optimization construction scheme of similar projects.