Plane Analysis Of Seismic Response Of The Underwater Saturated Sandy Subsoil With Shield Tunnel

Seismic response study of underwanter stratum is important to underwater tunnel design.In this paper, the problem of plane scattering of the complicated ground of underwater saturated sandy subsoil with circular shield tunnel is solved by analytical method. Underwater stratum-tunnel structure-water system seismic response is studied on the basis of the analytical solution. Emphasis is put on the affect of water on the river bed, coast bed and surrounding rock. Furthermore, example of the model is given and analyzed. A series of results are obtained.Firstly, based on Biot dynamic theory for saturated porous medium, analytical solutions for scattering of plane SV waves by the complicated ground of underwater saturated sandy subsoil with circular shield tunnel is given using Fourier-Bessel series expansion technique;Secondly, numerical results are given based on the analytical solution. The influence of water depth, buried depth and earthquake frequency on the stress and displacement magnify factor of tunnel surrounding rock and stratum of water-soil interface are studied.The results are valuable to the seismic response analysis of the complicated ground with a circular shield tunnel in underwater saturated sandy soil and the tunnel design.