基于FLAC^(3D)的地铁车站深基坑开挖变形三维数值分析

Numerical analysis of the deformation law of deep foundation pit of subway station by FLAC^(3D)

以某地铁车站深基坑工程为依托,介绍了该工程拟建场区的周边环境、水文地质条件以及支护结构选型。根据工程特点将其分为六个典型工况,运用FLAC3D建立三维数值模型对基坑开挖进行数值模拟计算,旨在研究"钻孔咬合桩+内支撑"这一支护结构在地铁车站深基坑工程施工中的变形规律,分析了其水平位移、钢支撑轴力及其周围土体的沉降规律和沉降影响范围。并根据支撑位置的不同对深基坑变形的影响,对该基坑工程的支护设计方案进行了优化。通过与原方案的对比,得出优化方案在控制变形等方面有一定的改善。本文的研究成果可为今后地铁车站深基坑工程的合理设计与安全施工提供参考。

Taking the deep foundation pit engineering of a Subway Station as background.The paper introduces the project＇ s surroundings, geological and hydrological conditions of the proposed field and the retaining structural type. According to the engineering characteristics, the project was divided into four typical operating conditions, the deformation rules of deep foundation pit at subway station in tunneling are studied with the method of FLAC3D numerical simulation, the supporting structures choose by the bored piles and interior support.The analysis of the horizontal deformation of the retaining structures, the axial force changes of steel support, the settlement law and the influence sphere of surrounding soil.For installation of prop structures on the performance of deep excavations is investigated through numerical analysis with site specific subsurface conditions, based on the analytical results, the design of supporting structures for the deep excavation construction can be optimized.The improved design had a bettrt performance in deformation con troll during the excavation comparison to the old design.The conclusion in this paper can provides reference for the reasonable design and safety construction of deep foundation pit.