Study on the Response of Tunnel Lining under Fault Dislocation

In order to clarify the influence of fault dislocation on tunnel lining, the FEM and single factor variable methods were used to explore the influence of the degree of fault dislocation, dip angle, width, the intersection angle between the strike and the tunnel axis, and the fault dislocation form on the lining structure response, based on which length of the lining anti-dislocation set-up for engineering design was obtained. The research shows that the maximum displacement of the lining is basically consistent with the fault displacement; with the increase of the fault width, the overall fortification range of the tunnel increases. Among the three types of fault dislocation, the axial force of the lining caused by reverse fault dislocation is the largest, the level of normal fault is the moderate, and the strike-slip fault is the smallest. With the increase of the intersection angle between the fault strike and the tunnel axis, the lining gradually changes from tension-shear failure to shear failure. It is suggested that the tunnel should cross the fault at a large angle as far as possible. If it is unavoidable to cross the fault when selecting the tunnel route in the project, the tunnel axis should be selected to cross the fault vertically as far as possible.