The seismic response mechanisms of segmental lining structures applied in fault-crossing mountain tunnel: The numerical investigation and experimental validation

To mitigate the seismic damage of the fault-crossing tunnel, this paper researches the scope influenced by the fault and proposes a setting method of the segmental lining. It is concluded that the segmental lining has a significant effect on reducing the shear stresses and compressive stresses, and the shorter the segment, the more obvious the effect. Furthermore, the normalized parametric analyses show that the seismic damage degree of fault-crossing tunnel increases with the decrease of the value of D/t (D is the tunnel diameter and t is the wall thickness), and the arch springing with the smallest D/t is the most critical position to be damaged. The middle section of fault rupture zone is the most dangerous and the seismic effect of the tunnel structure on the hanging wall is more severe than the seismic effect on the footwall. The proposed influenced scope of tunnel structure and the setting method of the lining segment can provide a reference for the aseismic design of the fault-crossing tunnel.