Study on the Mechanical Properties of Tunnel Corrugated Plate Support in Fault Sliding Zone

The permanent ground movement caused by earthquake is the main reason for the damage of tunnel structure. The corrugated structure has good large deformation ability, and its application in tunnel support is gradually increasing. However, there are few studies on the mechanical properties of tunnel corrugated plate support under fault dislocation. In this paper, a strike-slip fault simulation device is developed. Based on the similarity ratio theory, loose sand and PVC spiral corrugated pipe are selected to carry out the model test of corrugated plate support for cross-fault tunnel, and the circumferential and axial deformation of spiral corrugated pipe under different dislocation distances is obtained. Then the soil spring coefficient of pipe-soil interaction is determined by the specification. The spiral corrugated pipe with fault dislocation is numerically simulated and compared with the test, and the change of soil spring coefficient is obtained. Finally, the influence of rib stiffness and soil constraint on the supporting performance of tunnel corrugated plate under fault dislocation is studied. The results show that the maximum axial tensile and compressive strain occurs on both sides of the fault. With the rib stiffness increasing to certain value, the deformation of corrugated plate and the maximum ground dislocation distance keep stable. Under the same deformation of corrugated plate, the stronger the soil constraint, the smaller the maximum ground dislocation distance.