Dynamic behavior of fault tunnel lining under seismic loading conditions

The tunnel lining structure will withstand diseases such as cracking, collapse and dislocation in earthquake action, and heavy losses will be brought, especially when the tunnel passes through the fault. In this study, FLAC(3D) software was used to construct the surrounding rock-lining structure model of the across-fault tunnel based on a tunnel in Sichuan, China. The influence of fault width and dip angle on the dynamic response of tunnel lining structure was studied, and the variation of displacement, internal force and tunnel plastic zone were analyzed. The results showed that the shear effect is the clearest influence of fault fracture zone on the tunnel. The larger the fault dip angle, the more favorable it is to the tunnel lining structure. The larger the fault width, the larger the fault influence zone, and the more unfavorable it to the tunnel lining structure. The results can provide a theoretical basis for the improvement of seismic measures when tunneling through faults.

Automated summary

In this study, the FLAC(3D) software was used to construct a model of the surrounding rock-lining structure of a tunnel crossing a fault in Sichuan, China. The influence of fault width and dip angle on the dynamic response of the tunnel lining structure was studied, and the variation of displacement, internal force, and tunnel plastic zone was analyzed. The results showed that the shear effect is the most significant influence of the fault fracture zone on the tunnel. The larger the fault dip angle, the more favorable it is to the tunnel lining structure, while the larger the fault width, the larger the fault influence zone, which is unfavorable to the tunnel lining structure. These results can provide a theoretical basis for improving seismic measures when tunneling through faults.