Dynamic Response of a Circular Tunnel with a Piecewise Lining and Embedded in a Poroelastic Medium (No. R853)

In this paper, dynamic response of a circular tunnel with prefabricated piecewise lining embedded in a porous medium subjected to seismic waves is studied. The surrounding saturated porous medium of the tunnel is described by Biot’s theory. The piecewise tunnel lining consists of several lining pieces connected by joints. Both the lining pieces and the joints are treated as curved beams. The scattered wave field in the porous medium is obtained by the wave function expansion approach. The differential equations governing the vibration of a curved beam is discretized by the General Differential Quadrature (GDQ) method. The domain decomposition method is used to establish the global discrete dynamic equations for the piecewise lining. In terms of the boundary least square collocation method, the coupled problem is solved by the stress and displacement continuation conditions between the porous medium and the tunnel lining. Numerical results demonstrate that the stiffness difference between the liner piece and joints can enhance the internal forces of the piecewise liner significantly, which is crucial for the design of a piecewise tunnel liner