地铁深基坑开挖过程中支撑对围护墙的影响分析

The Influence Analysis of the Braces on Retaining Wall during the Excavation of Metro Pits

城市地铁的深基坑开挖一般都位于交通、人流和建筑物密集的中心城区,施工场地相对狭窄,而且需要考虑到对周边建筑物、道路等工程设施的保护,这种复杂环境下的施工对稳定和变形控制相当严格。本文以厦门地铁一号线工程为依托,选取位于繁华市区的吕厝站基坑的典型断面,用岩土有限元软件Plaxis模拟基坑分步开挖过程,研究所布置多道支撑的轴力、层数、间距和位置变化时对围护墙的水平位移和内力的影响,本项研究可供设计方案优化时参考。

Deep excavations of urban subway system are generally located in those central city areas which are traffic dense, built - up and crowded. Hence the construction sites are relatively narrow. The protection of surrounding buildings, roads, engineering facilities, should be necessarily taken into account in de- sign. In this complex environment, some restrict controls are instituted on keelMng stability and detaining deformation. In this paper, Lvcuo Station, a typical section of Xiamen No. 1 Metro project, is selected as a practical example. By numerical simulation using soil and rock engineering software Plaxis 2D , the in- fluence of multi - channel brace properties by steps, including axial force, layers, distance and position, on internal force and deformation of foundation pit envelope is investigated. This study would provide the basis and reference for further design and construction of Xiamen Metro project.