高瓦斯低透气性煤层深孔预裂爆破增透技术研究及应用*

为解决高瓦斯矿井开采过程中煤体透气性差、瓦斯预抽周期长、抽采效果不佳的难题，提出利用深孔预裂爆破技术提高煤体裂隙发育度，增加煤体透气性，从而提高瓦斯抽采率的方法。通过现场调研、理论分析、数值模拟及工业性试验等方法，分析深孔预裂爆破卸压增透内在机理，确定爆破影响半径为4.5~5.3 m，并在A110605工作面进行现场应用，同时考察煤层增透效果。研究结果表明:煤层爆破致裂后，平均瓦斯抽采浓度提高了2.17倍，平均瓦斯抽采纯量提高了2.02倍，煤层透气性系数提高了近5.3倍，煤层卸压增透效果显著，很大程度上消除了煤与瓦斯突出危险性，为实现工作面的安全开采及正常接替提供了保障。

Research and application of deep hole pre splitting blasting technology for permeability enhancement in high gas and low permeability coal seam

In order to solve the difficult problems of poor gas permeability in coal,long cycle of gas pre drainage and poor drainage effect in the mining process of high gas mine,a method of using deep hole pre splitting blasting technology to improve the development degree of coal fracture,increase the coal permeability and thus improve the gas drainage rate was proposed.Through the on site investigation,theoretical analysis,numerical simulation and industrial test,the inherent mechanism of deep hole pre splitting blasting for pressure relief and permeability enhancement was analyzed,and the blasting influence radius was determined to be 4.5~5.3 m.The on site application was conducted in A110605 working face,and the permeability enhancement effect of coal seam was investigated.The results showed that after the blasting induced fracturing of coal seam,the average gas drainage concentration increased by 2.17 times,the average gas drainage pure amount increased by 2.02 times,and the permeability coefficient of coal seam increased by nearly 5.3 times.The pressure relief and permeability enhancement effect of coal seam was significant,which eliminated the risk of coal and gas outburst to a great extent,and provided guarantee for the safe mining and normal replacement of the working face.