Investigation of the Mechanical Properties of Shear in an Experimental Setting of Prestressed Anchor Cable in Mines

The mechanical characteristics of anchor cable (AC) play a vital role in determining the design of prestressed support for roadways in deep coal mines. To investigate the shear mechanical properties of AC, a multifunctional testing device for AC was developed, which can conduct mechanical behavior tests such as anchoring, tensioning, and shearing on full-size AC. The research results showed that under shear stress, the AC presented a Z-shaped or S-shaped morphology, and the failure morphology of the rock surrounding the partial contact area with the AC was consistent with the shape of the AC. The initial tensioning force of the AC and the method used to anchor it greatly influenced the shear force, axial force, and shear deformation experienced by the AC. The analysis of the test results involved examining the shear force and deformation properties of the AC at various stages, and proposing the stress and deformation pattern of the AC when subjected to shear forces. The AC was analyzed to determine its bending deflection, rotation angle, bending moment, and shear force distribution pattern, which provided insights into the composite fracture mechanism involving bending, tensile, and shear stress. The multifunctional testing device for anchor rods (cables) was developed, which can achieve mechanical behavior testing such as anchoring, tensioning, and shearing of full-size AC. The AC's shear force-displacement curve can be categorized into five stages, each characterized by distinct shear forces and deformation mechanisms.The influence of the initial pretightening force of the anchor cable and the anchoring method on the shear force, axial force, and shear deformation of the anchor cable is revealed.