Research on the full-section anchor cable and C-shaped tube support system of mining roadway in island coal faces

ABSTRACTAnchor cables often break in various forms. Tensile failure can be resisted by using high-strength materials, while there is no good solution for shear failure. A new supporting structure called Anchor Cable and C-shaped tube that can bear the transverse shear force was invented and a preliminary introduction to the mechanism of the structure is given. Field investigations and in-situ stress tests were carried out on the panel 3210 in the Nanguan Mine. The failure modes of the surrounding rock and cables and the in-situ stress test results show that the working face is obviously affected by the horizontal stress. Thus, a new full-section anchor cable and C-shaped tube support scheme were proposed. The results of FLAC3D show that the new scheme is excellent in controlling the surface convergence and plastic zone extension. The rationality of the scheme was verified by two-and-a-half months of monitoring. Compared with the original scheme, the amount of surface displacement was at least 20% smaller, and the time for the displacement to reach equilibrium was at least 27.4% shorter. The surface of the roadway is flat without supporting material damaging. The new scheme is worth popularizing in similar working conditions.