暗挖海底隧道地震动水压力响应分析

Analysis of effect of hydrodynamic pressure on undersea tunnels constructed by excavation method

考虑黏弹性人工边界与流固耦合作用,建立了衬砌结构-土-海水相互作用的力学模型,基于Newmark算法,利用ANSYS有限元软件分析了在不同地震激励和埋深条件下动水压力的影响机理与隧道衬砌的振动响应规律.计算结果表明:在含有竖向分量的地震激励下,动水压力对浅埋海底隧道的内力影响较大,分析时不容忽视;当隧道埋深超过一定值后,结构地震反应变化微小可忽略.同时,针对圆形海底隧道进行的有限元计算结果可为海底隧道的工程抗震设计提供参考.

A mechanical model is presented for evaluating the tunnel lining-soil-water interaction considering the viscoelastic artificial boundary and fluid-solid coupling effect. Based on Newmark method, the seismic response behavior of tunnel lining and the influence mechanism of hydrodynamic pressure under different buried depth and earthquake excitation are investigated by using the finite element analysis software ANSYS. The results show that the dynamic water pressure plays an important role when the vertical seismic excitation component exists, so it can not be ignored. When the buried depth of tunnel exceeds a certain value, the change amplitude of the seismic response of tunnel lining is minor, meanwhile, the finite element calculation results can provide a reference for the anti-seismic design of undersea tunnel project.