Numerical simulation of deep foundation pit dewatering and land subsidence control of Xujiahui Metro Station

The buried depth of groundwater level is fairly shallow in Shanghai, and pit dewatering measures are mostly adopted in construction of metro stations. This study refers to the deep foundation pit dewatering project of Xujiahui Station of Shanghai Metro Line No. 11. According to the site conditions of engineering geology and hydrogeology, design depth of enclosure structure and pit excavation of metro station, a numerical model of groundwater seepage is established. Through the inversion of permeability parameters based on the field pumping tests, the three-dimensional finite difference method is used to simulate the pit dewatering considering the initial and boundary conditions. The numerical results are consistent with the actual monitoring data of groundwater level. At the same time, the land subsidence induced by dewatering is calculated. The results indicate that the land subsidence around the pit can be controlled effectively.