采矿与安全工程学报 ›› 2015, Vol. 32 ›› Issue (2): 253-259.

• 论文 • 上一篇    下一篇

带有导向孔的浅孔爆破在留巷切顶卸压中的应用研究

  

  1. 中国矿业大学煤炭资源与安全开采国家重点实验室,深部煤炭资源开采教育部重点实验室,矿业工程学院,江苏 徐州 221116
  • 收稿日期:2014-04-28 出版日期:2015-03-15 发布日期:2015-06-23
  • 作者简介:陈勇(1981—),男,四川省成都市人,博士,讲师,从事巷道围岩控制与支护方面的研究。
  • 基金资助:

    煤炭资源与安全开采国家重点实验室自主研究课题项目(SKLCRSM13X07);国家自然科学基金项目(51174195);煤炭资源与安全开采国家重点实验室开放研究基金项目(11KF01);江苏省自然科学基金项目(BK20140210)

Study on the application of short-hole blasting with guide hole to roof cutting pressure relief of gob-side entry retaining

  • Received:2014-04-28 Online:2015-03-15 Published:2015-06-23

摘要: 厚层坚硬顶板切顶卸压是优化沿空留巷围岩应力和结构有效途径之一,将导向孔应用到切顶卸压中是新的尝试。基于浅孔爆破沿空留巷切顶卸压机制,利用LS-DYNA 数值模拟与理论分析相结合的方法,分析了导向孔作用机理,探究了参数选取对爆破效果的影响。研究结果表明:导向孔增加了自由面,对炮孔连线方向上的切向应力影响明显,提高了炮孔间裂隙贯通率和炸药能量利用率;装药孔不耦合系数取1.31 时可充分发挥导向孔应力集中效应;最大切向拉应力与导向孔直径呈正变关系,但对远离导向孔的位置影响微小。根据岩石的动态抗拉强度,确定装药孔间距1.2 m。

关键词: 导向孔, 沿空留巷, 浅孔爆破, 切顶卸压

Abstract: Roof cutting pressure relief is one of effective ways for optimizing the surrounding rock stress and structure in thick layer of hard roof, and the application of guide hole to roof cutting pressure relief is a new attempt. Based on the mechanism of short-hole blasting for roof cutting pressure relief in gob-side entry retaining, using the combination of LS-DYNA numerical simulation and theoretical analysis, mechanism of guide hole has been analyzed, and the effect of the selection of parameters on the blasting of rock mass has been explored. The results show that free surface of blast hole increases in the guide hole, which affects obviously to the tangential stress, and increases the fracture penetration rate and utilization rate of explosive energy; The guide will give full play to the role as stress concentration when charging hole non-coupling coefficient is 1.31;There is a positively change relationship between maximum tangential tensile stress and guide hole diameter,but it has little effects on the position away from the guide hole. According to the dynamic tensile strength of the rock, the charging hole spacing is determined as 1.2 m.

Key words: guide hole, gob-side entry retaining, short-hole blasting, roof cutting pressure relief