Study On The Released Range And The Critical Interlayer Spacing Of Upper Protective Coal Seam With Closed Distance

Along with the mining depth increase, the high gas mines and coal gas outburst mines have been increasing. So it has become an important task for mining engineers to guarantee safe mining by adopting efficient measures。This article is based on the theoretical analysis, according to the No 5 coal in PingDingShan coal Group actual coal formation conditions to establish a geological model, with numerical simulation methods, the main research are as follows: first, use ANSYS simulation software to calculate slip surface formation process and shaps in limit state after protective coal seam mining without consideration for the gas pressure,then can seek for gas flow channel, obtain the shape of plastic failure of coal seam floor similar with Prandtl-type, and very similar with the slip-line theory too; Secondly, use ADINA numerical simulation software through different gas pressure, different rock pillar thickness,s calculation, compared to draw minimum security rock pillar thickness after protective coal seam mining; third, Use ADINA with porous media materials FSI method, draw on the mining gas flow and the gas pressure dissipation process, and the protective coal seam and the Protective coal seam of gas pressure changes,then discuss the mechanism for gas flow of upper protective coal seam with closed distance.