露天含水炮孔台阶爆破数值模拟与分析

Numerical simulation and analysis of bench blasting in open water-bearing hole

为了改善晋宁磷矿因孔内积水而导致爆破效果不理想的情况,在单孔药量与药包埋深不变的情况下,只改变孔间距和排间距,利用LS-DYNA建立了孔间距为5、6、7 m,排间距为3 m和4 m的6组计算模型,并通过LS-Prepost进行分析。结果表明:改变台阶爆破的孔间距与排间距均改变了爆炸应力波的叠加效果,孔间距、排间距的大小存在临界值,低于临界值时选取单元有效应力值增幅较小,综合考虑单元最大有效应力,建议采用孔间距为600 cm、排间距为400 cm的孔网参数。将数值模拟所得孔网参数应用于现场爆破工程,统计分析发现大块率较改进前下降20.6%,爆堆松散程度良好,块度适中,炸药单耗由原先的0.33 kg/m^(3)下降至0.25 kg/m^(3)。

In order to improve the unsatisfactory blasting effect of Jinning phosphate due to the accumulation of water in the hole,under the condition that the amount of single-hole explosive and the embedding depth unchanged,only the hole spacing and row spacing were changed.Using LS-DYNA,6 sets of calculation models with hole spacing of 5 m,6 m,7 m and row spacing of 3 m and 4 m were established and analyzed by LS-Prepost.The results show that changing the hole spacing and row spacing of step blasting changes the superposition effect of the explosion stress wave.The hole spacing and row spacing have critical values,and the effective stress value of the selected element increases less when the critical value is lower.Considering the maximum effective stress of the unit comprehensively,it is recommended to use hole mesh parameters with a hole spacing of 600 cm and a row spacing of 400 cm.The hole network parameters obtained by numerical simulation were applied to the field blasting project.Statistical analysis found that the bulk rate decreased by 20.6%compared with the previous improvement,the blast pile looseness was good,the clump size was moderate,and the unit explosive consumption was reduced from the original 0.33 kg/m^(3)to 0.25 kg/m^(3).