The Following Protective Layer Destress Range And Degree Of Relief,

Along with the mining depth increase, the high gas mines and coal and gas outburst mines have been increasing. So it has become an important task for mining engineers to guarantee safe mining by adopting efficient measures.Based on theory analysis, with the colligation analysis method of computer simulation and colliery on-the-spot test, the rock failure and movement laws, the stress change and deform laws of the far-distance protected stratum, the penetrability change laws of the far-distance protected stratum, and the gas flow field of the far-distance protected stratum were studied for the low penetrability and high gas coal seam during the far-distance under-protecting stratum mining. Through reasonably arranging the pressure releasing gas drills, gas was extracted out and the gas content in the coal seam was reduced. The gas emission was lessen during the working face mining and avoid the danger of the coal and gas outburst in the protected layer, and the production efficiency in protected layer was greatly improved.The finding conclusions accorded with the measuring conclusions in coal mine. The scientific foundation have been got for the district preventing gas outburst and unloading pressure drawing gas, and the gas harm was resolved for the low penetrability high gas content and outburst coal seam with the far-distance protecting stratum mining successfully.