Seismic wave passage effect on dynamic response of submerged floating tunnels

In this paper, a numerical analysis is performed to investigate the dynamic characteristics of submerged floating tunnels (SFTs) under seismic wave passage effect. The large mass method is examined firstly and then used to simulate numerically the dynamic response of SFTs. It is found that the dynamic response of SFTs is influenced remarkably by the multi-support excitation with the seismic wave passage effect and varies with the velocity of seismic waves in a non-monotone way. The numerical results show that the response under the multi-support excitation is much larger than that under the simultaneous excitation except for the displacement response in some velocities, and there exists a peak velocity of seismic waves that corresponds the maximum response of the structure. In addition, for every velocity, the most remarkable response appears near the shore connection corresponding to output end of the seismic wave. This finding reflects the unique behavior of SFTs under the multi-support excitations and is meaningful to the seismic design of SFTs as well as other periodic long-span structures.