Influence of Rock Mass Weak Surface Failure on Periodic Weighting of Fully Mechanized Mining Face

The strata in the mine field are mostly sedimentary rock. Due to the influence of geological tectonics, there are weak surfaces such as joints, bedding and faults in the surrounding rocks of the stope. The paper indicates the fracture forms of surrounding rock weakness face. It analyzes the weakness face failure mechanism by Mohr-Coulomb strength theory, and gets the activation condition of weak face under the influence of mining action. Meanwhile, combining the study on the strata-pressure behavior of 1305 fully mechanized working face in Zhaozhuang No.2 coal mine, the periodic weighting interval decreases and the pressure strength decreases under the influence of weak rock mass. The failure scope of coal wall and roof becomes larger, and it is easy to have a large range of roof fall and wall caving.