四老沟矿坚硬顶板初采定向爆破弱化技术研究与应用

Research and application of directional blasting weakening technology for hard roof during initial mining in Silaogou mine

鉴于四老沟煤矿顶板厚度大、硬度大、强度高的特殊赋存条件,当工作面初采期间面临着初次来压步距大、初次破断极易诱发工作面动载灾害等难题,选取四老沟煤矿8108综放面为工程背景,提出爆破切顶弱化技术,采用理论分析及数值模拟研究爆破切顶角度与高度对坚硬顶板的弱化效果,得出最优切顶弱化方案;结合现场施工效果进行验证。研究结果表明,通过理论分析及数值模拟验证了方案3#的切顶参数(20.3 m、θ=50°)对坚硬顶板的弱化效果最佳。现场实践方面,从坚硬顶板弱化后的钻孔窥视验证了爆破弱化对坚硬顶板整层的破坏效果明显,从支架工作阻力验证了3#方案切顶参数的合理性,为工作面坚硬顶板控制技术研究提供了理论指导。

Due to the special occurrence conditions of the large thickness,high hardness and high strength of the roof for Silaogou Coal Mine,problems such as large step distance,initial breaking-induced dynamic disaster in working face,etc.easily occurs.The 8108 mechanized working face of the mine is taken as the research background,a blasting roof-cutting weakening technology is put forward,the weakening effect of blasting roof-cutting angle and height on hard roof is studied using theoretical analysis and numerical simulation,and an optimized scheme for roof-cutting weakening is got.The results show that the roof-cutting parameters(20.3 m,θ=50°)of the scheme 3#has an optimal roof weakening effect.The borehole peeping after roof weakening verifies that the whole roof’s breaking effect is obvious by blasting weakening,and the rationality of the 3#scheme’s roof-cutting parameters are verified by support working resistance.The study provides theoretical reference for the research on hard roof control technology.