Research on Protection Technology of Foundation Pit Excavation Adjacent to Existing Railway

Traffic safety in existing railway has strict demands to the subgrade deformation, and the subgrade deformation caused by foundation pit excavation should be under the limit value. In this paper, steel sheet pile cofferdam supporting system is introduced, as well as its construction process. 2D numerical simulation is adopted to simulate the construction process, the deformation of subgrade at different cases are discussed. At last, the field monitoring data is provided to verify the validity of supporting system and numerical simulation results. Research results indicate that steel sheet pile cofferdam supporting method can well control the subgrade deformation, and can be took as a precedence technique in similar engineering. To ensure the traffic safety, it´s necessary to prevent the trains crossing near the excavation, and the train speed should be limited.