Dynamic Analysis About the Effect of Foundation Pit Excavation Adjacent to the Existing Railway

During the Beijing-Shanghai Express Railway construction process, the construction of long bridges buttresses foundation pit excavation adjacent to existing Shanghai-Nanjing Railway is one of the most complex problems to be faced with. In this paper, taking one buttress foundation pit excavation engineering as example, a 3D FEM calculation model combined with the train, railway, subgrade, soil body and supporting structure is established to analyze the influence of excavation, including the railway subgrade vibration and deformation. The research result indicates that the subgrade deformation under the two-way train load is larger than the one under one-way train load, but the maximum value is under the limit value of train traffic safety. The foundation pit support method designed is reasonable and effective. At last, some advices are presented to ensure the traffic safety, including speed limited and crossing avoided.