地下矿山直眼掏槽爆破参数优化研究

针对凡口铅锌矿目前直眼掏槽钻孔数量多、凿岩效率低等问题,开展了直眼掏槽爆破参数优化研究。通过理论计算,确定了钻孔孔径以及装药孔与空孔间距的范围。运用LS-DYNA数值模拟软件对理论计算取值范围内不同孔径、装药孔与空孔间距等参数进行模拟研究,对各模拟方案下应力分布状态及关键单元的应力值进行分析。结果表明,空孔具有导向及应力集中作用,在装药孔及空孔孔径相同条件下,当孔径为0.051 m和0.058 m时,孔间距均应取0.30 m; 当孔径为0.064 m时,孔间距应取0.35 m。工程应用结果表明,这3种爆破参数方案均能达到预期爆破效果,综合爆破后矿石块度及凿岩效率,最终确定掏槽爆破参数为:孔径0.051 m,装药孔与空孔间距0.30 m。

Optimization of Blasting Parameters of Burn Cut in Underground Mine

In view of the large number of burn cut holes and low rock drilling efficiency in Fankou Lead-Zinc Mine, the parameters for burn cut were optimized. Based on theoretical analysis and calculation, the range of drilling hole diameter, spacing between charged hole and relief hole were determined. A simulation study was performed with LS-DYNA numerical simulation software for the parameters including hole diameters, spacing between charged holes and relief hole within the theoretical calculation range, and the stress distribution state and the stress value of key elements under each simulation scheme were also analyzed. The simulation study shows that the relief holes can provide an orientation and concentrate the stress. If the charged holes and the relief holes with the same diameter, hole spacing should be chosen at 0.30 m when the hole diameter is 0.051 m and 0.058 m, while the hole spacing should be 0.35 m when the hole diameter is 0.064 m. The engineering application shows that these three kinds of blasting parameter schemes can all achieve the expected blasting effect. With the blasted ore size and drilling efficiency taken into comprehensive consideration, the undercut blasting parameters are finally determined to be as follows: 0.051 m in diameter and 0.30 m of spacing between charged holes and relief holes.