Numerical analysis of segmental tunnel lining under seismic loads

Segmental tunnel linings are now often used for seismic areas in many countries. Unfortunately, the behaviour of segmental tunnel lining under seismic loads is still unclear. One of the most important elements in segmental tunnel lining is the presence of joints between segments. However, the influence of segment joints on tunnel lining behaviour during seismic loading has in fact not been quantitatively estimated in literature. This paper presents a numerical investigation on the performance of segmental tunnel lining under seismic excitation. Numerical analyses have been carried out using a two-dimensional finite difference element model. The seismic signal obtained from an earthquake in Nice has been adopted as input. The numerical results show that a segmental lining can perform better than a continuous lining during an earthquake. The effect of plasticity of the soil constitutive model on the tunnel lining has also been highlighted. The results indicated that an elastic analysis is not sufficient to determine the seismic induced response of a soil-tunnel system.