基坑开挖对下卧隧道的影响分析

Analysis of the Influence of Foundation Pit Excavation on the Underlying Tunnel

随着社会经济的不断发展,许多城市开始兴建地铁,以缓解城市交通压力,而基坑紧邻隧道进行开挖的案例也时常出现。为明确基坑开挖对下卧隧道的影响,本文以一位于隧道上部的基坑开挖工程为例,采用PLAXIS 2D有限元软件进行基坑的支护及开挖步骤分析,研究基坑开挖期间隧道位移及应力的变化。结果表明,随着基坑开挖的推进,隧道变形逐渐增大,隧道最大变形出现在隧道顶部,隧道最大弯矩出现在隧道两侧的水平位置处。

With the continuous development of social economy,many cities have begun to build subways to relieve ur ban traffic pressure,and cases of excavation of foundation pits next to tunnels often appear.In order to clarify the im pact of foundation pit excavation on the underlying tunnel,this paper takes a foundation pit excavation project locat ed in the upper part of the tunnel as an example,and uses PLAXIS 2D finite element software to analyze the founda tion pit support and excavation steps,and studies the changes of tunnel displacement and stress during foundation pit excavation.The results show that as the excavation of the foundation pit progresses,the deformation of the tunnel gradually increases,the maximum deformation of the tunnel appears at the top of the tunnel,and the maximum bend ing moment of the tunnel appears at the horizontal position on both sides of the tunnel.