Dynamic Response of Curved Wall LTSLS Under the Interaction of Rainwater Seepage and Earthquake

When water permeates the loess, the strength of the loess will be greatly reduced; thus, it is necessary to study the effect of seepage on the seismic response of a loess tunnel. Fields of structure and fluid are simulated using ADINA, and the calculation model of a curved wall loess tunnel with a super-large section (LTSLS) is established. Rainwater is simulated using an incompressible constant parameter model. Considering the action of near- and far-field earthquake and pulse effects, the Galerkin method is used to solve the interaction of stress and seepage fields. By contrasting and analyzing the maximum principal stress, the minimum principal stress, the maximum displacement of lining and the internal force of the tunnel structure, the influence of rainwater seepage on the mechanical properties of LTSLS is studied, and meanwhile, dynamic responses of LTSLS under the interaction of rainwater seepage and earthquakes are studied. The results show that if rainwater seepage is only considered for shallow buried LTSLS, the pore water pressure of a tunnel is so small that it may be neglected. The damage degree of LTSLS under the interaction of rainwater seepage and earthquakes is more than that under a single field. When considering the interaction effect of rainwater and earthquakes, the pore water pressure, principal stress and displacement under a near-field earthquake with pulse effect are greater than those under a near-field earthquake without pulse effect and a far-field earthquake under the same condition.