Displacement Analysis Of Adjacent Subway Station Due To Deep Excavation And Study On Protection Measure Of Construction

With the developing of Shanghai economy, underground engineering project in the downtown has been increasing fast. Mass subway stations and tunnels were constructed in the center location of city due to the development of Urban Rail Transport. Plenty of deep excavation projects adjacent to the subway stations and tunnels make the environmental geotechnical to be a serious problem. The rigorous deformation requirement of subway station structure makes the construction of deep excavation which has common wall with subway the station structure very difficult. The displacement of station wall and structure must be controlled in allowable range for the normal operation of station.In this paper, in order to analyze the influences on the subway station and the surrounding soil due to the deep excavation of YueYang to the station which adjacent to the subway station and has common wall with subway station, a two dimensional elastic-plastic finite-element model, which employs the HS elasto-plasticity soil constitutive model, was made. Through comparison, verification and back-calculation, the result calculated from the FEM model was uniform with the measured value.The influences on the excavation and the subway station due to the load of the airport terminal and the YueYang square one was analyzed by above FEM model, then the influences on the displacement filed of soil layers around the station and the displacement of station is demonstrated in this paper. Through the numerical simulation, the influences of various parameters on the subway station displacement are investigated, including the space effect of excavation, the effect of width and depth of the cement-mixed pile on the displacement control of the subway station. Then some practical conclusions are drawn for the deep excavation adjacent to subway station and the method of ground treatment.