低透气性高瓦斯煤层深孔控制预裂爆破增透技术

为了解决低透气性高瓦斯煤层难抽采问题,运用RFPA2D数值模拟软件,建立了2种深孔控制预裂爆破力学模型,通过对模拟结果进行对比分析,得出一套适用于鹤煤八矿底板抽采的爆破参数,并进行了现场试验,爆破后煤层透气性系数平均值达到了2.23 m2/（MPa2.d）,比爆破前测定的煤层原始透气性平均值提高了近3.05倍,说明该技术可以明显提高钻孔周围煤体裂隙发育程度,煤体透气性增加,达到了提高煤层瓦斯抽采量和抽采率的目的。

Permeability Increase with Deep Borehole Controlled Pre-cracking Blasting Technology in Low Permeability and High Gassy Seam

In order to solve the difficult gas drainage problem in low permeability and high gassy seam,the RFPA2D numerical simulation software was applied to establish two deep borehole controlled pre-cracking blasting mechanics models.With the comparison and analysis on the simulation results,a set of blasting parameters obtained which were suitable for floor gas drainage in No.8 mine of Hegang Coal Mining and the site trial with the parameters was conducted.The results showed that after the blasting,the average value of the seam permeability coefficient reached at 2.23 m2/(MPa2·d)and 3.05 times higher than the average value of the seam in-situ permeability before the blasting conducted.Thus the technology could obviously improve the cracking development degree of coal around the borehole and could improve the permeability of the seam.The target to improve the seam gas drainage value and the gas drainage rate could be reached.