坚硬顶板爆破切顶在沿空留巷中的应用研究

当煤层上方为坚硬顶板时,在工作面回采期间容易出现大面积悬顶,导致巷旁充填体出现大变形破坏,极大威胁采煤安全.为解决这一问题,以某矿1205工作面沿空留巷为工程背景,分析了爆炸围岩裂隙范围和坚硬顶板破断特征,建立了切顶卸压围岩结构力学模型,研究表明,相邻炮孔爆炸后,炮孔间裂隙互相贯穿,降低了顶板强度,同时当切顶角为15°时,巷道稳定性较好.工程实践结果表明:采用爆破切顶技术后,顶板下沉量减小了62.3%,较好地保证了围岩稳定性.

Study and Application of Cutting Roof in Gob-Side Entry Retaining by Blasting

In the process of working face mining,the hard roof above the coal seam is easy to appear large area hanging roof,which leads to the deformation and destruction of the backfilling body and greatly threatens the safety of coal mining.For solving this problem,this paper analyzes the fracture range and the breaking characteristics of the hard roof in 1205 working face of a mine,and establishes a mechanical model of the structure of the cut-top pressure relief surrounding rock.After the explosion of adjacent holes,the cracks between the holes run through each other,which reduces the roof strength.at the same time,when the cutting top angle is 15°,the stability of the roadway is better.The results of engineering practice show that the roof subsidence is reduced by 62.4%.