Analytical solution for long tunnels in layered saturated poroelastic ground under inclined P1-SV waves

The analytical solution for dynamic responses of long tunnels in horizontally layered saturated poroelastic ground subjected to inclined P1-SV waves is deduced in this paper. The free field responses of the layered saturated poroelastic ground are obtained by the stiffness matrix method. The tunnel is assumed to be an infinitely long beam resting on a viscoelastic foundation. The soil skeleton displacements of the saturated ground are converted to dynamic loads imposed on the tunnel by the viscoelastic foundation. The analytical solution is verified by degenerated solutions and numerical solutions. Results show that SV-waves induce greater internal forces of the tunnel than P1-waves. Parametric analysis is performed on incident angles of plane waves, soil tunnel flexibility ratios and frequency of input motions. The proposed solution could serve as a useful tool for practitioners in seismic analysis and design of tunnels.