Modeling Experiment on Effect of Normal Fault with 45° Dip Angle Stick slip Dislocation on Tunnel

Abstract:

The force deformation mechanism and failure process under the effects of stick slip dislocation of the normal fault with 45° obliquity was studied by a 1∶50 model experiment. And the strata pressure of the tunnel vault and bottom, axial strain and hoop strain were monitored. Results show that the strata pressure on the vault in the hanging wall and the shear zone increases significantly, followed by the pressure on the vault in the foot wall. The pressure on the tunnel bottom in the hanging wall and the shear zone decreases, while it greatly increases in the foot wall. The tunnel is separated from the wall rock so as to accommodate the shear displacement of the fault. The longitudinal bending moment in the hanging wall and the shear zone is positive and negative in the foot wall zone. By judging the lining failure from the cement prototype under compression, the maximum allowable fault displacement of the prototype is D=0.7 m. Theoretically, the value is overestimated. Tunnel lining fracture length is 1.7 and 2.8 times the width of the tunnel in the shear zone and foot wall respectively.