The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

239 / 2018-05-05 18:26:05

Numerical Simulation and Field Application of Deep Hole Pre-splitting Blasting Technologies for Gas Drainage under Different Conditions

deep hole pre-splitting blasting,coal seam,gas drainage efficiency,gas control,numerical calculation

Gas of Coal Mine & Coal and Gas Outburst > Gas of Coal mine

Deep hole pre-splitting blasting has been proved to be an effective method to improve gas drainage rate and prevent gas outburst in coal mines. However, the occurrence of gas in coal mines in southern China is complex and changeable, which results in limited application of deep hole pre-splitting blasting in gas control. According to the characteristics of different coal mines, individual methods of deep hole blasting are adopted to improve the gas drainage effect and expand application range. Based on the combination of numerical simulation and field application, the blasting parameters of different mines are determined according to the relationship between the change of blasting stress field and gas discharge data. In this paper, the blasting crushing zone and the influence range of gas drainage after deep hole blasting in the coal seam are studied in Datong coal mine. The results show that the gas flow rate of the draining hole 6m from the blast hole has been increased by 24%. For the soft coal seam in Yuyang coal mine, the blast hole is difficult to be formed. Therefore, the method of drilling and blasting in the rock seam adjacent to the coal seam is adopted, and the gas flow rate of the draining hole increases by 125%. Through application of deep hole blasting through strata to gas drainage in Shiping coal mine, the gas drainage gross is found to be increased obviously with effective stress increasing, and the gas drainage gross is increased by 3.3 times when distance between the bottom of the blast hole and the draining hole is 4.6m compared to that when the distance is 8.8m. The blasting methods mentioned above have achieved good results in 26 outburst mines in Southern China, which is of great significance to the application of deep hole pre-splitting blasting in many fields of gas control in the future.