合肥大学城基坑开挖对既有建筑物的影响分析

Analysis of Influence of Foundation Pit Excavation on Existing Buildings in Hefei University

通过有限元软件建立合肥大学城深大基坑三道支撑开挖三维数值模型,研究了开挖过程中周边隧道和支撑的应力和变形演变规律,并给出相应的控制策略和工程建议。研究表明,随开挖深度的增大,附近隧道同时发生上浮和向基坑方向的侧移两种位移,且基坑中部对应的隧道总位移最大。随着开挖的进行,附近隧道会同时发生向上位移和向基坑侧向位移两种位移,且基坑中部对应的隧道总位移最大,为保护地铁隧道等重要地下工程,建议在开挖前设置地下连续墙和挡土桩。

On the finite element software,the three-dimensional numerical model of the excavation of three supports in the chengshen large foundation pit of Hefei University is established,and the stress and deformation evolution law of surrounding tunnels and supports in the excavation process is studied,and the corresponding control strategies and engineering suggestions are given.The results show that the horizontal displacement and settlement of the existing buildings around the foundation pit increase with the excavation depth.In order to protect the important underground engineering such as subway tunnel,the diaphragm wall can be set up before excavation.In the process of excavation,the horizontal displacement and settlement of the pit top will gradually increase,so it is suggested to set up the retaining pile to balance and restrain.With the progress of excavation,two kinds of displacements will occur simultaneously in the nearby tunnel:upward displacement and lateral displacement towards the foundation pit,and the total displacement of the tunnel corresponding to the middle part of the foundation pit is the largest.In order to protect the subway tunnel and other important underground projects,it is suggested that the underground diaphragm wall and retaining piles should be set up before excavation.