基于深孔预裂爆破的坚硬顶板卸压研究

Research on Pressure Relief of Hard Roof Based on Deep Hole Presplitting Blasting

针对坚硬顶板导致煤柱变宽,影响巷道开采的问题,根据煤柱的应力分布特征,给出了采煤极限尺寸的计算方法。考虑到煤柱应力的形成条件和传递形式,提出了一种预裂与深孔爆破相结合的方法来减弱煤柱应力,再利用数值模拟分析了煤柱的应力分布,并通过现场工业试验进行了验证。结果表明,预裂使应力阻断,越靠近煤柱应力的峰值,阻断效果越好。结合2种爆破方法,将煤柱尺寸减小到60 m。结合预裂和深孔爆破的方法可以有效地减小煤柱的尺寸,并减小开采对倾角巷道变形的影响。

According to the stress distribution characteristics of coal pillar,the calculation method of mining limit size is given.Considering the formation conditions and transmission forms of coal pillar stress,a method combining presplitting and deep hole blasting is proposed to reduce the coal pillar stress.Then,the stress distribution of coal pillar is analyzed by numerical simulation and verified by field industrial test.The results show that presplitting blocks the stress,and the closer it is to the peak value of coal pillar stress,the better the blocking effect is.Combining the two blasting methods,the size of coal pillar is reduced to 60 m.The combination of presplitting and deep hole blasting can effectively reduce the size of coal pillar and the influence of mining on the deformation of inclined roadway.