矿山掘进爆破周边孔轴向间隔装药数值模拟及应用*

在岩石坚硬的巷道掘进爆破时，常采用周边孔连续装药形式，针对装药量过大而导致的炸药周围超挖严重及孔口因岩石强度较大却出现欠挖的问题，提出采用轴向空气间隔装药结构。根据理论计算爆破后粉碎区的长度，并结合类似矿山相关经验，确定装药间隔长度40 cm，并对40 cm间隔长度数值模型模拟分析。结果表明，40 cm空气间隔装药能保证良好的爆破效果，使炸药下部岩石在充分破坏的前提下能保护上部围岩不受破坏，且能保证孔口岩石产生受拉破坏。通过现场试验，验证了在坚硬岩石中采用空气间隔装药爆破，相比无空气间隔的爆破，在保证巷道整体成型的情况下，周边孔的半孔数量增加，爆破效果显著提升。

Numerical Simulation and Application of Air decked Charge in Periphery Hole of Mine Excavation

Continuous charge is often used in the blasting of hard rock roadways.In view of the serious overexcavation around the explosive caused by too much charge and the underbreak problem of the hole due to the strength of the rock,the axial air interval charge structure is proposed.According to the theoretical calculation results of the length of the crush zone after blasting and the relevant experience of similar mines,the charging parameters of the interval length is determined as 40 cm.The numerical model of 40 cm interval charge structure was built and the simulation analysis is carried out.The results show that good blasting effect can ensured by 40 cm air interval charge,so that the lower rock of the explosive could protect the upper wall rock from being damaged under the premise of sufficient destruction,and could guarantee the tensile failure of the orifice rock.Field tests are conducted to verify the blasting effect of air spaced charge in hard rock.Compared with the blasting without air spaced charge,the number of semi holes in surrounding holes increased and the blasting effect is significantly improved under the condition of ensuring the overall formation of roadway.