中深孔全断面切缝管定向断裂爆破技术应用研

分析了切缝管定向断裂爆破裂纹的形成与扩展机理，在切缝处应力集中和压力差共同作用下形成初始裂纹，而后的裂纹扩展经历了切向拉伸应力作用下的扩展阶段、爆生气体驱动压力作用下裂纹稳态扩展和爆生气体驱动下的宏观裂纹扩展3个阶段。在理论分析的基础上结合工程实际，提出了切缝管药包定向断裂复合楔形掏槽爆破和周边孔切缝管药包定向断裂爆破技术。现场应用效果表明：切缝管爆破可提高炮孔利用率和眼痕率，降低爆破对围岩的扰动损伤，改善掏槽爆破和周边爆破效果，有利于提高巷道掘进速度。

Research on Middle-deep Hole Directional Fracture Blasting Technology of Cut Tube in the Whole Section

The formation and propagation mechanism of directional fracture blasting crack of the slit tube were analyzed.The initial cracks were formed under stress concentration and pressure difference at cut joints.Then the crack propagation process experienced the growth stage under the action of the tangential tensile stress，steady crack propagation phase and macroscopic crack propagation caused by detonation gas driving pressure.On the basis of theoretical analysis and engineering practice，the directional fracture blasting technology of joint-cutting cartridge in composite wedge cut holes and peripheral holes were proposed.The spot application indicated that the cut tube blasting can improve the utilization rate and hole mark rate of blast holes，reduce the blasting disturbance damage to surrounding rock and improve the effect of cut blasting and perimeter blasting.In brief，it is conducive to quicken speed of roadway drivage.