坚硬顶板预裂爆破模拟分析与研究

Simulation Analysis on Pre-split Blasting of Hard Roof

阐述了坚硬顶板爆破成缝的原理,并根据402工作面实际情况选择了不同的参数,建立了不耦合装药、切缝药包以及V型刻槽三种爆破模型。针对上述三种模型,对比分析相应的孔壁压力发现,切缝药包爆破产生的预裂效果最好。通过对此模型进行模拟计算,得到了测点应力随时间变化的曲线,进一步发现在与炮孔间隔2.75 m处所测得的最大拉应力高于顶板岩层的抗拉强度,说明两炮孔互相贯穿,从而证明了此次爆破的炮孔间距确定为5.5 m是合适的。

In this paper,the principle of blasting a hard roof into a seam was introduced.In addition,parameters were selected for the actual No.402 working face and three blasting models were established,including decoupling charge,slotted cartridge and V-shaped notching blasting.The comparison of their corresponding pressure on borehole wall showed that the pre-split effect produced by the slotted cartridge blasting was the best.The simulation calculation obtained the stress variation curves at measuring points.Moreover,it was found that the maximum tensile stress measured at 2.75 meters from the blasting borehole was higher than the tensile strength of the top strata,indicating the two blasting boreholes penetrating each other,which could prove suitable the 5.5 meters of the blasting borehole spacing.