针对高瓦斯低透气性煤层瓦斯超限影响煤巷掘进速度问题,建立深孔预裂爆破三维有限元模型进行数值模拟研究。模拟结果表明,深孔预裂爆破经历了冲击波冲击煤岩产生裂纹、稀疏波使煤体裂纹扩展以及爆轰气体驱动裂纹扩展3个过程(0—5ms),增透深孔预裂爆破爆破孔合理间距为3—5m.
Aiming at the problem that the gas overrun influences tunneling speed of coal roadway in high gassy and low permeability coal seam, a three-dimensional finite element model was built to present a study on numerical simulation. The study results show that the deep-hole pre-splitting blasting experiences three processes in 5ms, cracking caused by shock wave lashing coal-rock and crack propagation driven by sparse wave and explosion gas. The study also reveals reasonable interval (3 -5 m) between explosive holes of deep-hole pre-splitting blasting is for permeability enhancement and the technique can improve the effect of gas extraction and increase coal seam permeability.