某露天采场深孔台阶爆破空气间隔装药的应用

Application of Air Interval Charge in Deep-hole Bench Blasting in Open-pit Mine

为了改善某露天采场爆破作业中存在的振动大、大块率高等问题,采用中部空气间隔装药法代替连续装药法并对空气间隔比例进行对比研究。基于ANSYS/LS-DYNA有限元软件构建装药不变条件下空气间隔比例分别为10%、12.5%、15%、17.5%和20%的中部空气间隔方案计算模型进行模拟分析:装药量不变条件下空气层比例为17.5%时,炮孔中、底部有效应力分布均匀,没有出现应力过度集中现象,效果最佳。经过现场试验后证明:采用空气层比例17.5%的中部空气间隔装药爆破后,大块率下降了27.26%、振动降低5%~12%,有效降节约了经济成本。

To solve the problems of a large open-pit mine in blasting operations, such as high boulder yield and vibration, the central air interval charge method was used to replace the continuous charge method and the air interval ratio was compared. Based on the ANSYS/LS-DYNA finite element software, the calculation model of the central air interval scheme with 10%, 12.5%, 15%, 17.5% and 20% air separation ratio under the condition of constant load was simulated. When the ratio of air layer is 17.5% ,the effective stress distribution in the bottom of the hole is uni- form, and the stress concentration is not concentrated. The blasting results is the best. After field test, it was proved that the boulder yield was reduced by 27.26% and the vibration was reduced by 5% to 12% after the middle air gap charge of 17.5% that the air layer was used. The economic cost was reduced and provide a reference for the solution of the other similar problems.