Influence of foundation pit excavation approaching a metro station

Based on a pit excavation near a metro station in Guangzhou, a series of 2D nonlinear calculation models considering the interaction of the metro station, surrounding soils, and the foundation pit retaining structure are established by finite element software. The influence of pit excavation on the deformation and dynamic response of the metro station under different intervals and excavation depths is studied. The results indicate that the deformation distribution of the station has obviously been changed due to the adjacent excavation. The closer and deeper the excavation is, the more obvious the effects on the station are. The deformation of the station mainly indicates vertical uplift and movement towards the internal side of the foundation pit. With an increase of excavation depth, horizontal displacement of the station changes obviously, and the vertical displacement changes a little, while the differential displacement has changes a lot, significantly affecting the structure. With an increase of excavation depth and a decrease of interval distance, the vibration response of both the foundation pit support structure and the station is affected, which further aggravates the structure vibration. Finally, the technical countermeasures to control deformation of the station structure are presented, providing a reference for similar projects in the design and construction phases. ©, 2015, Editorial Office of Modern Tunnelling Technology. All right reserved.