94 / 2023-06-14 22:18:50

Numerical study on progressive damage and failure of coal seam suffered from impact loads generated by hard roof fracture

coal damage,dynamic failure,roof fracture,impact loads,roadway stability

Coal damage and roadway stability are essential issues encountered in underground coal mine, especially under impact loading conditions such as hard roof fracture, fault slip, and blasting activities. It is therefore necessary to assess the coal damage and roadway stability under impact loading conditions. In this study, a numerical approach was proposed to assess the progressive damage and failure of coal under impact loads. The numerical approach was verified with the experimental results in SHPB tests and proved to be able to reproduce coal failure under impact loads. The results indicate that the final coal damage is positively related to the loading rate of impact loads. In addition, the numerical approach was further utilized to assess the roadway stability under dynamic impacts induced by hard roof fracture in coal mine. The results show that the top and junctions between top and both sides of the roadway encounter serious damage, and the final damage is positively associated with the roof strength. Field observations further verified the numerical results, which transpires that the proposed approach is a feasible method for the roadway stability assessment under impact loading conditions.