Shear Test of Pre-stressed Anchor Block and Fracture Mechanism Analysis of Anchor Cable

The large-scale model test bench frame is adopted to carry out shear test on the pre-stressed anchor block containing structural plane, and the characteristics of tensile, bending and shear failure of anchor cable are analyzed. Furthermore, the structural calculation software ABAQUS 2020 is utilized to construct the spiral structure model of composite steel wires and the anchor cable is simplified to be composed of bending inner and outer steel wires and central steel wire, so as to simulate accurately the interaction, failure mode and mechanical mechanism between anchor cable and grouting body, as well as between grouting body and concrete block. The results show that the anti-shearing process of pre-stressed anchor blocks can be divided into the anti-shearing stage of structural plane and the anti-shearing stage of anchor cable. Affected by the anti-shearing and deformation characteristics of the bending inner and outer steel wires, the shear stress of the anchor cable has experienced an alternate change process from strong to weak, then from weak to strong, and finally to weak. The axial force of the anchor cable continuously increases until the fracture of the anchor cable. Anchor cable fracture first appears at plastic hinge position of the inner bending steel wire, and then at the interface between the anchor cable and the structural plane, the central steel wire occurs tensile–shear fracture.