Comprehensive analysis of safe mining to heavy and steep coal seam under complex geophysics environment

In virtue of effect of N-S intensive ground stress and mining disturbance to +579E2EB1+2 mining site at Weihuliang Mine, the dip angle and section height is 65° and 52 m, respectively, the collapses happed frequently during mining. Firstly, mining conditions, spatial structure and parameters were investigated. Then physical simulation and dynamic numerical tracing and elaborate simulation relating roof and top-coal were applied based on 2D-Block Program and quantitative regularity of stress at variable depths had been estimated. Furthermore, it was manifested that effective measures, i.e., fast mining, control symmetrical top-coal-caving at dip and strike directions, optimizing ventilation system, active-stereo preventing gas were performed successfully in mining practice. Ultimately, the derived dynamic hazard were prevented so as to safety mining.