针对低透气性突出煤层钻孔抽采瓦斯难、石门揭煤速度缓慢等问题,研究了低透气性煤层深孔预裂爆破卸压增透的防突机理,通过理论分析、深孔预裂爆破药柱研发及现场试验相结合的方法,测试了淮南矿区某矿东四采区B组5-2煤层深孔预裂爆破煤层松动半径;依据此参数,优化设计了5-2煤层抽采钻孔和爆破孔。结果表明:在低透气性突出煤层实施深孔预裂爆破增透技术措施后,煤体的弹性潜能得到有效释放,煤层瓦斯压力梯度降低,有效消除了激发突出的应力,煤层的透气性系数提高了123倍,煤层瓦斯抽采纯量比爆破前提高了6~9倍,石门揭煤时间大幅缩短,仅为47 d,比传统的揭煤方法揭煤时间缩短近2个月,为采掘正常接替提供了保证。

According to the difficult borehole gas drainage in the low permeability outburst seam, the slow seam opening speed of the crosscut and other problems, the paper had a study on the outburst prevention mechanism of the pre-cracking blasting and permeability improvement with the deep boreholes in the low permeability seam.With the theoretical analysis, the research and development of the deep borehole pre-cracking blasting explosive cartridge and the site test combined method, th e pre-cracking blasting vibration radius with the deep boreholes in No.5-2 seam of the Dongsi district B group of a mine in Huainan Mining Area was measured.Based 0 n the parameters, the gas drainage boreholes and the blasting boreholes in No.5-2 seam were optimally designed.The results showed that after the pre-cracking blastin g and permeability improvement technical measures with the deep boreholes completed in the low permeability outburst seam, the elastic potential of the seam was effe ctively released, the gas pressure gradient of the seam was reduced and the excitation outburst stress was effectively eliminated.The permeability coefficient of the sea m was increased by 123 times and the pure quantity of the gas drainage from the seam was improved by 69 times higher than before the blasting operation completed. The seam opening time of the crosscut was highly reduced and was only 47 days which was reduced about two months faster than the seam opening time with the conv entional seam opening method and could ensure the normal replacement of the mining and excavation operations.

国家自然科学基金资助项目(51004003,50974004)；安徽高校省级自然科学研究重点资助项目(KJ2010AO91)；