Numerical simulation for large-scale seismic response analysis of immersed tunnel

This paper presents a three-dimensional numerical simulation method for large-scale seismic response calculation based on a newly built immersed tunnel in Shanghai. The whole analytical model consists of the surrounding soil, the tunnel segments, and the detailed flexible joints. Both the number of nodes and the number of elements exceed one million. This model takes account of nonlinear material behavior such as soil, non-reflecting boundary definition, and soil–tunnel interaction. Final calculation has been performed on the Dawning 4000A supercomputer using the finite-element code LS-DYNA 970 MPP. The result provides a global understanding of this immersed tunnel under seismic loading and reveals the weak parts. It also provides relevant data and references for the aseismic design of immersed tunnel and flexible joints in the future.