坚硬顶煤弱化的深孔爆破合理炮孔间距研究

Rational Blast Hole Space of Deep Hole Blasting for Hard Top-coal Weakening

为了解决千树塔煤矿11301工作面顶煤硬度大、工作面回采期间顶煤不能及时垮落和充分破碎的问题,采用理论分析和数值模拟的方法研究了深孔爆破后炮孔周围的裂隙扩展情况和裂隙圈范围。结果表明,在炮孔直径为94mm、药卷直径75mm的条件下,千树塔煤矿的顶煤经爆破后炮孔周围的裂隙圈范围约为1.5m,最终确定合理的炮孔间距为3m。以此为依据设计了11301工作面的顶煤深孔爆破方案,实践后工作面顶煤采出率得以明显提高。

In order to solve the top-coal caving difficult problem which result from large top-coal strength, theoretical analysis and nu-merical simulation was applied to obtaining cracks development and cracks circle range after deep hole blasting.Results showed that crack circle range of top-coal was about 1.5m after blasting with 94mm borehole diameter and 75mm cartridge diameter, and rational borehole space was obtained to be 3m.On the basis of this, top-coal deep hole blasting project of 11301 mining face was designed.Top-coal recovery had been obviously increased after application.