Some Predictions of Deformations from Tram Track Construction in a Structure-Embankment Transition Zone

Abstract

Based on a construction project of a tram line in Nanjing City of China, the influence of a tram track construction on the deformation characteristics of an adjacent metro station and tunnels is investigated. Because a section of the tram track is designed to be constructed in the vicinity of the connection between a metro station and metro tunnels, the foundation of the tram track is changed from the station structure to the normal embankment. As a result, deformations from tram track construction in this structure-embankment transition zone will be serious. In order to protect the metro station and the twin tunnels from the construction-induced deformation and long term settlement caused by tram trains, a recommended treatment of the structure-embankment transition zone is suggested according to the property of the surrounding soils. The construction process of the tram track over the metro station and the tunnels is simulated by a finite element analysis (FEA) method. The deformation characteristics of the metro station and tunnels are calculated. Results indicate that with the recommended transition zone design the deformation response of the adjacent underground structures can be well controlled and the transition performance of the tram track transition zone can be improved.