为了解决高瓦斯低透气性煤层的瓦斯抽放难题,利用数值模拟和现场测试相结合的方法,研究了深孔预裂爆破技术对高瓦斯低透气性煤层的卸压增透效果。研究结果再现了爆破过程中,动压冲击震裂、应力波传播与叠加及爆生气体驱动裂纹扩展的整个过程,分析了爆破孔间距对爆生裂纹和增透效果的影响,提出了高瓦斯低透气性煤层深孔预裂爆破的合理间距,表明深孔预裂爆破技术有效地提高了煤层透气性和瓦斯抽采率。该成果为高瓦斯低透气性煤层的瓦斯抽放提出了解决方案。
It is difficult to conduct gas drainage in a high gassy and low permeability coal seam. This paper presents a study to comprehend the performance of increasing permeability by deep-hole pre-splitting explosion using numerical simulation and field measurement. The study reveals the process of explosion, cracking caused by dynamic pressure, stress wave transmission and superposition, and crack propagation driven by explosion gas. Also, the study investigates how the pre-splitting drillhole interval affects the crack generation and the permeability enhancement. Therefore, an optimal pre-splitting drillhole interval is proposed for a high gassy and low permeability coal seam. The study shows that the deep-hole pre-splitting explosion technique can increase coal seam permeability and gas drainage rate. The technique provides a new solution for gas drainage in high gassy and low permeability coal seams.