深孔预裂爆破技术在井筒揭煤中的应用研究
Study on Application of Deep Borehole Pre-Fracturing Blasting Technology to Seam Opening in Mine Shaft
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摘要: 针对淮南矿区井筒揭穿低透气性突出煤层施工周期长,很大程度上制约矿井采掘接替等问题,提出了利用深孔预裂爆破技术,增加煤体透气性,提高瓦斯抽采量,缩短井筒揭煤时间的新方法。主要研究了深孔预裂爆破煤层增透防突的作用机理,模拟分析出某矿第二副井13-1煤层的爆破松动半径为4 m,优化设计了井筒揭煤钻孔布置方案;现场考察了深孔预裂爆破煤层增透后瓦斯抽采纯量较爆破前增大了4倍,提高了煤层瓦斯抽采率,从而使井筒揭13-1煤层时间缩短至32 d。Abstract: According to a long period to sink through a low permeability and outburst seam during a mine shaft sinking in Huainan Mining Area and the mining and excavation connection highly restricted problems,a new method of the deep borehole pre-fracturing blasting was provided to improve the seam permeability,to improve t he seam gas drainage rate and to reduce the seam opening time of the mine shaft sinking.The paper had a study mainly on the function mechanism of the seam perme ability improvement and the outburst prevention with the deep borehole pre-fracturing blasting.The paper had a simulation and analysis on the blasting with a loosing ra dius of 4 m in No.13-1 seam of No.2 Mine Auiliary Shaft in the mine and the borehole pattern plan to open the seam in the mine shaft was optimally designed.The site i nvestigation showed that after the deep borehole pre-fracturing blasting conducted for the seam permeability improvement,the gas drainage pure volume was increased by 4 times than before the blasting conducted,the seam gas drainage rate was improved and thus the 13-1 seam opening time of the mine shaft sinking was reduced by 32 days.