Technology Research Of Deep Hole Presplitting Blasting To Improve Gas Pumping Rate Of Zhaojiashan Coal Mine

Deep hole presplitting blasting as an important technology in order to increase air permeability, which directly affects the efficiency of gas drainage and coal mine production safety, efficiency and its direct impact on gas extraction. According to methane concentration overrunning of Zhao jia shan coal mine at Qing Xu, the reason is tunneling process a large amount of gas emission and coal seam permeability characteristics of the poor, the existing drainage system drainage indicators reach the expected results. After the geological condition, the gas emission law by experimental data and Zhao jia shan coal mine in studies of blasting excavation, decided to make gas control in the working face of deep hole presplitting blasting technology application. Gas flowing theory as a foundation, a numerical simulation is conducted in deep hole presplitting blasting experiments, using numerical analysis software COMSOL for simulation of gas flow pattern and distribution, provides the solid basis for the next step pumping gas.In the field test, using different aperture and the blasting hole with controlled pore spacing is different, the comparison of the two groups in the experiment, the collected data as the basis, study on the effect of pre splitting blasting effect of pore size and spacing of two factors. According to the test data, in order to achieve a good blasting effect, indifferent kinds of conditions, selection of drilling hole diameter and the distance is not the same. The test coal seam Zhao jia shan belt heading face No.2, Lane implemented through comparative analysis of several experimental results, when the hole spacing is 6m, blast hole diameter is 113mm,94mm aperture control hole when drilling in the gas The maximum concentration, extraction best.Mining and concentration from the original 21% to 37% draw the highest single hole, t he digging working face extraction rate increased from 20% to 40.8%,the tunneling surface gas overrun problem can be solved, to achieve the desired effect, accelerate the driving speed, this research is going to use this process after the gas control to provide a reliable basis for.