Precise Judgment of Reverse Fault-Induced Water Inrush Hazard under Influence of Roof Goaf Water

Abstract

Previous research recognized the threat of faults to safe mining and the importance of identifying fault failure patterns, and began to use theoretical research and numerical simulations to study the activation laws of faults during mining. Conventional wisdom may suggest that the height of the fractured water-conducting zone (FWCZ) of the overburden strata over goaf will be increasingly caused by fault activation, thereby causing roof water inrush, in particular, goaf water existing in the roof of working face. Therefore, the FWCZ in the overburden strata make accurate judgments that are regarded as a key foundation to evaluate the safety of coal mining under water bodies. In view of this problem, the 15,103 working face of Wenzhuang Coal Mine in Shanxi Province were taken as the engineering background, the height of the FWCZ of the adjacent 15,100 working face was observed by drilling fluid leakage method and drilling television method, the observed results provided a reference for judgment of the height of the FWCZ of 15,103 working face. Additionally, the drilling method was adopted to conduct exploration on the terminal location of F6 reverse fault in overburden strata of No. 15 coal seam, the result showed that the disturbance range of F6 reverse fault was located in the FWCZ formed after mining the 15,103 working face. Furthermore, the method of numerical simulation analysis was used to study the failure height of overburden strata after mining the 15,103 working face through F6 reverse fault. The height of the FWCZ of F6 reversed fault was basically equal to that of the upper and lower plates, and F6 reverse fault had no influence on the height of the FWCZ after mining the 15,103 working face. There was a sufficient thick overburden strata between the maximal elevation of the fractured zone and the roof goaf water, and mining through F6 reverse fault under old goaf was safe and reliable. The research results can provide reference for the safe mining of passing through reverse faults under the influence of roof goaf water.