A full-ring mechanical model of shield tunnels considering detailed joint configurations

Abstract

Shield tunnels are segmentally assembled structures with joints, which are predominant factors affecting tunnel deformation and waterproofing performance. Detailed joint configurations (sealing gasket grooves, caulking grooves, etc) profoundly influence the full-ring mechanical behavior of shield tunnels. However, the existing analytical model usually ignores the detailed joint configurations. This paper proposed a full-ring mechanical model of shield tunnels considering detailed joint configurations. In this model, the tunnel is modeled as a multi-hinged circular ring, and joint behavior is characterized by a full-process analytical model incorporating detailed joint configurations. The proposed model effectively captures the influence of detailed joint configurations on tunnel mechanical behavior including the internal force and deformation of both global full-ring and local joints, and is validated through a series of case histories. Furthermore, parametric studies show that: (1) The tunnel with the outer-side arrangement of double sealing gaskets exhibits higher leakage risks in the hogging moment zone and demonstrates greater convergence deformation compared to both-side arrangement. (2) Bolt height elevation enlarges internal joint openings while reducing external openings. Convergence exhibits a U-shaped relationship with bolt height, minimizing at 0.5H∼0.54H. (3) Convergence deformation and joint openings escalate with sealing gasket distancing from the joint external edge, whereas gasket deformation slightly changes.