基坑开挖对下卧管线竖向变形影响的数值分析

基坑开挖会对下卧管线产生不利影响,如何控制基坑开挖对下卧管线产生的不利影响是工程界的热点问题.以杭州市沿江大道管廊基坑上跨污水管段工程为背景,利用ABAQUS软件进行数值模拟,建立了三维有限元模型.在此基础上分析了管线周围土体注浆加固的作用,同时研究了改变管线与基坑的夹角引起管线竖向位移的变化规律.分析结果表明:上方基坑的开挖会使下卧管线呈现出"中间大、两边小"的"上凸型"变形模式,对下卧基坑管线周围进行合理的注浆加固,能有效减少管线的整体隆起变形;且下卧管线与基坑长边夹角越大,管线的最大隆起位移越小,当管线与基坑长边垂直时,管线的隆起变形最小.研究结果可为今后类似工程提供借鉴.

Numerical Analysis on Influence of the Foundation Pit Excavation on the Vertical Deformation of Subjacent Pipelines

The excavation of foundation pit will inevitably cause adverse effects on the subjacent pipeline. How to reduce this effect is a very important problem. In this paper, based on the project of the foundation pit excavation of Yanjiang Avenue in Hangzhou, ABAQUS software was used for numerical simulation, and a three-dimensional finite element model was established. On this basis, the effect of grouting reinforcement of soil around the pipeline was analyzed. By changing the angle between the pipeline and the foundation pit, the influence of the angle change on the vertical deformation of the pipeline was studied. The analysis results show that the excavation of foundation pit will make the underlying pipeline present a convex deformation mode of "large in the middle and small on both sides". The reasonable grouting reinforcement around the underlying foundation pit pipeline can effectively reduce the overall uplift deformation of the pipeline, and the larger the intersection angle between the underlying pipeline and the long side of the foundation pit, the smaller the maximum uplift displacement of the pipeline. The research results of this paper can provide reference for similar projects in the future.