Finite Element Stimulation And Monitoring Data Analysis Of Deep Pit Support Structure Deformation Of A Subway Station

As the development and utilization of underground space in large cities, the depth and difficulty of deep foundation pit of subway station is increasing. However, deep pit engineering is a more complex geotechnical problem. During the foundation pit excavation, construction accidents often come out as the large deformation of the soil and the supporting structure, which is due to the uncertainty of the geological conditions and the variability of the construction factors. Therefore, during the foundation pit design and construction, design parameters and construction parameters should be adjusted according to the particular cases, which are very important for the safety of deep pit and surrounding environment.The basic theory of deep foundation pit deformation and three dimensional finite element of deep foundation pit supporting stimulation are studied. The finite element model of deep pit was established, the method of the initial stress field is solved, and the method to avoid the steel brace pre-stress loss is solved. And then, practice is executed based on the background of the deep pit of Yongtai Station Guangzhou Metro Line. By the three dimensional finite element analysis, the major factors which impact the pit deformation are studied, such as diaphragm stiffness, the stiffness of the brace, the pre-axial force of steel brace and space effect. The parameters of supporting structure are fixed and specific programs of excavation and support are proposed. The monitoring results and the finite element results are analysed and the deformation control measures are summarised, which can offer reference for the similar deep foundation pit design and construction.