Seismic response analysis of shield tunnels in liquefiable soils

The prefabricated lining segments of shield tunnels are their most significant structural feature. The current researches on the seismic response of shield tunnels mainly adopt simplified methods, lack of dynamic response analysis, which can reflect the characteristics of tunnel segments and joints effectively. Further researches are needed to understand the seismic response of shield tunnels in liquefiable soils. A computational model for prefabricated tunnel linings is proposed in FEM program. A unified constitutive model for large post-liquefaction deformation of sand is used for liquefiable ground. The analysis results show that the joint is a key aspect of the seismic design of shield tunneling. The fabricated tunnel segment structure is more flexible than the monolithic structure under seismic loading. The tunnel is horizontally compressed in liquefiable soil, and the seismic response is distantly different from that in the non-liquefiable soils.