ABSTRACT
This paper investigated the longitudinal deformation behavior of a shield tunnel caused by overlying excavation based on a case study from Shenzhen, China. A soil-tunnel interaction model, which combines the structural model proposed by Wu et al. (2015) with the Winkler foundation, was proposed to analyze the deformation behaviors of the longitudinal structure as well as the circumferential joints of the tunnel. By comparing the predicted tunnel settlement with the measured results in the case history of Shenzhen, the effectiveness of the proposed soil-tunnel interaction model was verified. The calculated deformation of the circumferential joints was compared with the leaking location of the groundwater observed in the inner surface of the shield tunnel. The results indicated the groundwater leakage generally occurred between the location with the maximum opening of joint and the location with the maximum shearing dislocation. This further indicated the longitudinal deformation of the shield tunnel was accumulated by both bending opening and shearing dislocation in the joints, rather than pure opening of joints that commonly used in the previous studies and the waterproofing design.
