ABSTRACT
It’s inevitable to excavate foundation pits in the proximity of the existing metro station with the rapid development of subway in congested urban area. In this paper, the response of an operating metro station to the adjacent excavation was investigated. Zoned excavation method and an improved construction procedure of conducting excavation and basement construction alternately were adopted. The vertical displacements of rail tracks, entrance structure and convergence of shield tunnel were extensively analyzed. The results show that the excavation leads to the heave of station, while the construction of basement imposed reloading effect on the environment, which could balance excavation unloading effect in a certain degree. Therefore, the vertical displacements of metro station were within the acceptance limit. The entrance experienced tremendous settlements with a maximum value of 21.75mm, which is different from the behavior of metro station. The shield tunnel moved horizontally to 5.30mm because of lateral stress relief.
