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With the acceleration of the process of China's urbanization, a large number of infrastructure needed to the construction of the various uses of underground space and facilities will be an unprecedented development. The construction of these projects is the first to face the deep excavation. Deep excavation of the pit itself and the surrounding environment is one of the main contents of the pit engineering. East Railway Station of Hangzhou Metro Line Station soft soil deep foundation pit engineering background, through theoretical analysis and numerical simulation of the horizontal displacement of underground continuous wall during excavation around foundation surface subsidence and earth pressure variation and the impact of foundation pit deformation, the factors surrounding surface subsidence and adjacent to the railway embankment settlement system. The key findings are as follows: (1) as the excavation depth increases, the horizontal displacement of the wall and the surrounding surface subsidence corresponding increases excavation depth of roughly proportional to the amount of change with each step, and earth pressure with open digging depth increases correspondingly reduced. (2) plus solid foundation pit reinforcement commonly used method of reinforcement and reinforcement calculation results show that of the two programs, plus solid able to significantly reduce the horizontal displacement of the wall, the surrounding surface subsidence and railway embankment settlement. When the stringent requirements of the surrounding environment on pit deformation of soil reinforcement, is the most effective measures to improve soil strength. (3) underground continuous direct impact on the thickness of the wall stiffness, wall thickness of 0.6m, 0.8m, 1.0m, 1.2m, 1.4m, 1.6m calculation results show that increasing the thickness of the diaphragm wall can effectively reduce the wall horizontal displacement, differential settlement around foundation surface subsidence and adjacent railway embankment. However, the wall thickness is greater than 1.4m, increasing the thickness effect is no longer evident, wall thickness 0.8m ~ 1.4m advisable. (4) underground continuous wall depth is an important parameter of the pit design, wall depth of 55m, 53m, 50m, 48m, 46m, 44m, 42m, 40m calculation results show that, with the wall depth is reduced, the pit final The horizontal displacement of the wall below the excavation face significantly increased; away from the pit edge closer to the regional surface subsidence decreases, increased remote regions of the surface subsidence; uneven settlement of the railway embankment decreased. (5) the support stiffness is an important parameter of the support system, the support stiffness as a design value of 0.5 times, 1.0 times, 2.0 times, 4.0 times, 6.0 times, 8.0 times, 10.0 times, the calculation results show that increasing the support rigidity can be reduced uneven settlement of the horizontal displacement of the wall, around foundation surface subsidence and near the railway embankment. However, when the support stiffness of up to 2.0 times the value of the design, increasing the stiffness effect is no longer evident. The support of the original design stiffness similar Pit is appropriate.
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