Study On The Movement Law Of The Floor In Steep Thick Coal Seam Mining With Hard Roof,Soft Coal And Weak Floor In Bozidun Coal Mine

Based on occurrence condition of main mining coal seam in Bozidun Coal Mine, with working face 31101 coal floor as the research object, by adopting the combination of physical simulation, theoretical analysis and numerical simulation, fracture characteristics and sliding rule of floor are studied and summarized under the condition of thick coal seam with hard roof, soft coal and weak floor. The main research results are as follows:(1)Characteristics and regularity of floor damage in working face 31101 is obtained. The main destruction of the floor is tensile failure.( 2) Based on elastic-plastic mechanics and material mechanics theory, calculating the range, the rule and the first location to damage of coal floor, the largest floor specific pressure to prevent hydraulic support to drill floor is obtained, which can provides related theory parameters of hydraulic support.(3)Using of numerical simulation and MATLAB software, analyzing activity rule of coal floor under the condition of different angle, it is concluded that the critical dip angle of coal seam floor sliding.