地铁车站深基坑围护结构设计及其稳定性分析是地铁建设中的关键课题之一，开展黄土地区地铁车站深基坑围护结构变形规律研究对指导西部地区深基坑信息化施工具有重要价值。本文以黄土地区某城市地铁车站深基坑工程为背景，采用理论分析、现场监测和数值模拟相结合的方法，对黄土地区城市地铁车站深基坑变形规律进行了研究，主要内容和结论如下： （1）研究结果表明，水文地质条件、基坑大小及土压力值、设计方案、施工方法与组织的合理性以及基坑渗流对深基坑变形影响较大；深基坑的变形主要包括三个部分：墙体变形、基坑底部隆起和周围地表沉降；破坏模式主要有弓形变形模式、深埋式变形模式、前倾型变形模式、踢脚型变形模式四种。 （2）完成了BDJ车站深基坑不同围护方案的比较与选型论证，在施工之前进行了降水设计计算；给出了黄土地区某城市地铁车站深基坑围护结构的设计方案，并重点对围护桩、钢支撑及锚索进行了初步设计。 （3）制定了BDJ车站深基坑施工监测方案，并完成了现场监测工作。着重分析了围护桩的变形、钢支撑轴力变化和锚索受力变化的规律。结果表明，桩体位移是围护结构变形特性的直接反映，而钢支撑和锚索对深基坑变形有明显的限制作用。工程实践表明，围护结构设计方案基本合理，监测方案可行。 （4）运用FLAC软件对该深基坑开挖过程进行了仿真模拟，计算结果和监测结果比较，变化趋势一致；同时分析了黄土地区黄土湿陷性对深基坑变形的影响，结果表明，在一定范围内，随着黄土粘聚力增大，基坑变形量有所减小。

Design of the retaining structure and stability analysis of deep excavation in metro station is one of the key issues in metro construction. The study on the theory of deformation laws and monitoring of deep excavation in metro station in one city has great significance to guide informational construction in deep excavation in west. In this paper, it uses the method that combines with the theoretical analysis, in-situ monitoring and numerical simulation followed the background of deep excavation of South Gate metro station. The main jobs are as follows: (1) The main factors affecting the deformation of deep excavation are analyzed, and the deformation principles and failure modes of retaining structure are studied. The research shows that the hydro geological conditions, the foundation size and earth pressure, design decision, the rationality of the construction methods and organization, and the pit seepage greatly impact the deformation of deep excavation. The deformation of deep excavation consists of three parts: the wall deformation, the bottom heave of the pit and the Surrounding ground settlement. The failure pattern of deep excavation contains the bow-shaped deformation mode, the buried-type deformation mode, the forward-type deformation mode, and the kick-type deformation mode. (2) The comparison of different support programs and the selection argument is completed，It designes the precipitation program and proposes the design program of retaining structure of deep excavation of metro station in one city in Loess area, and gives the preliminary design focus on supporting pile and steel support and cables selectively. (3) It designes the in-situ monitoring plan of deformation, and accomplishes the in-situ monitoring work. At the same time, it focuses on deep analysis of the horizontal deformation of the retaining piles, the axial force of steel support, the force of cables. The results show that displacement of pile is a direct reflection of deformation of the retaining structure, while the steel support and cables of the foundation significantly limiting deformation. The results of this engineering show that the design program of retaining structure is basically rational and monitoring is feasible. (4) By the use of the software FLAC, a simulation of the entire process of excavation is accomplished, and the discipline of the displacement of the excavation and pile and the cables are given. It indicates that the calculated results are identical with the measured ones. Also, the impact on the loess collapsibility of the deformation of deep excavation in Loess area is analyzed. The results show that pit deformation decreases along with the cohesion increasing within a certain range.