深孔爆破对隐患资源开采两帮的动力响应特性研究

隐患资源安全开采是采矿工程领域面临的难点问题。结合某铅锌矿隐患资源开采工程实际情况,利用显示动力分析软件LS-DYNA构建深孔爆破荷载作用下充填体动力响应的数值仿真模型;设计了5种不同装药结构,分析爆炸应力波在充填体环境下的传播特征。结果表明:隐患资源两帮受到的拉应力小于其动态抗拉强度,两帮不会发生"片落";采用不耦合装药并且空气间隔系数为0.52可以使爆破应力分布更均匀;爆破振动速度和应力叠加使药包中心点到充填体的投影位置的速度和应力达到最大值;爆破参数为:炮孔直径为110 mm,排距×孔距=2.0 m×1.8 m,边孔与充填体之间的距离为1 m,一卷炸药(长0.67 m,直径90 mm)+1 m空气间隔的边孔装药结构即方案4。现场试验表明,优化的装药结构可以较好解决深孔爆破对隐患资源开采稳定性的问题。

Research on Dynamic Response Characteristics of Deep Hole Blasting for Two Sides of Hidden Resources

Safely mining of hidden resources is a difficult problem in the field of mining engineering.Combined with hidden danger resources mining engineering practice of the Fankou lead-zinc mine,the numerical simulation model of dynamic response of backfill under deep hole blasting load was constructed by using the dynamic analysis software LS-DYNA.5 different charging structures were designed and propagation characteristics of explosive stress wave in filling body were analyzed.The results show that the tensile stress of two sides of hidden resources was less than the dynamic tensile strength,two sides won't exfoliate.The blasting stress distribution was uniform by using the decoupling charge and the air gap coefficient 0.52.Speed and stress of the projection position of the explosive center to the filling reached the maximum because of the superposition of blasting vibration velocity and stress.The blasting parameters were given as blasting hole diameter 110 mm,row spacing and hole space 1.8m × 2.0 m,distance be-tween side hole and filling body 1 m,with charging structure of a piece of dynamite and air space.The field test shows that the optimized charging structure solved the problems of deep hole blasting on the stability of the hidden resources well.