非对称不耦合装药结构对预裂爆破效果的影响

Impacts of Asymmetric Decoupling Charge Structure on Presplitting Blasting Effect

为降低爆破开挖对保留区岩体的损伤,采用数值模拟的方法,研究不同装药结构对预裂爆破效果的影响,发现相比于中心单药卷和偏心双药卷,偏心单药卷装药结构下的预裂缝成型效果最佳,且其炮孔壁上的爆炸荷载在保留区一侧较小,在开挖区一侧较大,能在降低爆破开挖对保留区岩体损伤的同时将爆炸能量更多的作用于开挖区岩体。基于偏心单药卷装药结构,在综合考虑预裂缝成型效果和保留区岩体损伤程度的情况下,通过数值模拟的方法研究了爆破参数对预裂爆破效果的影响,结果表明:在不耦合系数为1.68,炮孔间距为70 cm的条件下,预裂爆破效果最佳。

To reduce the damage on the reserved rock mass by blasting excavation, the influence of different charging structures on blasting effect was studied through numerical simulation. It is found that the asymmetric charging structure with single cartridge formed the best presplitting crack, and caused smaller blasting load on the hole wall at the side of reserved area and bigger blasting load at the side of excavation area, which reduced the damage on reserved rock mass and takes more blasting energy on excavation area as well. On the basis of asymmetric charging structure with single cartridge, the influence on blasting effect of presplitting blasting parameters was also studied through numerical simulation, and the asymmetric charging structure with single cartridge reached the optimal blas- ting effect with decoupling coefficient 1.68 and hole spacing 70 cm by comparing with presplitting crack forming and the damage degree on reserved rock mass.