深孔断顶爆破防治冲击地压的理论与实践

简要阐述我国冲击地压作用机制及控制技术研究现状,深入探讨深孔断顶爆破的作用机制,采用数值模拟方法分析深孔断顶爆破防治冲击地压的基本原理,对于爆破前后的应力场进行对比分析,从计算结果来看,深孔断顶爆破能够从根本上改变煤岩体的应力分布状态,显著降低爆破有效范围内煤岩体中的应力水平,应力峰值出现的位置明显远离煤壁,峰值的大小大幅度降低;结合急倾斜煤层开采条件和倾斜煤层开采条件,进行深孔断顶爆破防治冲击地压的实践,并通过应力监测对其卸压效果进行检验。监测结果表明,采用深孔断顶爆破技术能够有效改变煤岩体的应力状态,对具有冲击危险的区域起到较好的卸压作用;在华亭煤矿急倾斜煤岩层条件下深孔断顶爆破的实践中,在监测期间内,深孔断顶爆破后顶板岩层出现3次明显的周期性垮断现象,压力显著降低,周期来压明显,从而降低冲击危险性,有利于矿井的安全生产。

THEORY AND APPLICATION OF PREVENTION OF ROCK BURST BY BREAK-TIP BLAST IN DEEP HOLE

Based on the review of occurrence mechanism of rock burst and control technique in China,the mechanism of break-tip blast is profoundly discussed in deep hole of coal rock.The theory of break-tip blast for preventing rock burst is studied by numerical simulation method.The comparison is done between the stress fields before and after blasting.The result shows that the break-tip blasting ultimately changes the stress distribution of coal rock and markedly decreases the stress of coal rock in the effective range of blasting.The stress peak value reduces and the position of the peak point is far from coal wall.This technique has been applied to the mining condition of steeply pitching seam and sloping seam.The effectiveness of pressure relief is checked through stress monitoring.The result indicates that the stress state of coal rock is effectively changed by the technique of break-tip blast in deep hole.Three periodical breakdowns are detected after break-tip blast in deep hole of coal rock in Huating mine.The pressure is reduced and the periodical pressure is distinct.The bursting risk decreases favoring the safety of the mine.