Deformation Monitoring And Numerical Simulation Of Deep Foundation Pit Retaining Structure Deformation In Subway Station

With the rapid development of the city, underground space is more and more being used, but due to the narrow city land and large population, subway station deep foundation pit construction is more and more difficult. However, due to the deep foundation pit is a very strong comprehensive geotechnical engineering problems which involves many subjects, all kinds of uncertain factors have a great effect on the safety of the deep foundation pit, therefore, the subway station deep foundation pit retaining structure deformation monitoring and numerical simulation study is of great significance.In this article,based on the Dongting Park Station of Wuhan Subway branch4, the deformation law of retaining structure of Subway station are studied on with methods of theoretical research, in-situ monitoring and numerical simulation of finite elemen,the main work is as follows:(1) The deformation mechanics and destroy pattern of deep foundation pit is studied from the aspects of soil rebound of the pit bottom, inclinometer of retaining structure and settlement of soil,and the main impact factor of deep foundation pit deformation is analysised. From the analysis, the failure pattern of deep foundation pit contains the bow-shaped deformation mode,the buried-type deformation mode,the forward-type deformation mode, the kick-type deformation mode,and the horizontal-push deformation mode.And the main influential factors are: Hydrogeological conditions, the surrounding environment of pit,climate conditions, size of deep foundation pit, design factors and construction factors.(2) Combined with the hydro-geological conditions and the design scheme of retaining structure,it designes the in-situ monitoring Scheme of deformation and the monitoring method for each monitoring project,and it focuses on the analysis of the changes of the horizontal displacement of retaining structure and steel support axial force in the construction process.(3)The two-dimensional finite element analysis model was established using the PLAXIS software according to the actual situation of the project,it gets the simulation results under various conditions. And then according to the analysis results compared the simulated results with the measured results, it shows that the deformation results obtained by the two methods is consistent on the overall trend. However, due to the actual situation are many unknown factors, the finite element simulation of the horizontal displacement value slightly larger than the actual measured value. The contrast between the results provide a reference for future construction of the subway construction.