引水隧洞光面爆破周边孔炸药匹配性试验研究

Experimental study on matching of explosives in peripheral holes of smooth blasting inheadrace tunnel

为确保引水隧洞爆破施工过程高效有序的进行,以秘鲁圣加旺引水隧洞前期开挖段为工程背景,通过LS-DYNA软件建立周边孔简化的双孔引水隧洞爆破损伤模型,研究乳化炸药、铵梯炸药、铵油炸药炮孔周围的损伤范围,并采用EMULEX 80的试验数据验证了数值模拟的可靠性,最后结合引水隧洞现场实际分析不同炸药密度、爆速、爆压对炮孔附近岩体损伤范围的影响。研究结果表明:在数值模拟中,乳化炸药能够形成空气连线处裂隙区,且单个炮孔对围岩的损伤范围最小为47.5 cm;乳化炸药的炸药密度、爆速、爆压分别在1.12~1.14 g/cm^(3)、4500~5000 m/s、8000~9000 MPa区间光面爆破效果最好。对比8次现场试验得到的结果,在EMULEX 65、EMULEX 80乳化炸药的基础上考虑对装药结构进一步优化以提高现场施工的经济效益。研究结果对引水隧洞爆破开挖中超欠挖以及损伤控制有一定的指导作用。

To ensure the efficient and orderly progress of the blasting construction process,based on the San Gaban water diversion tunnel in Peru,a simplified double-hole blasting damage model was established using LS-DYNA software,with the early excavation section of the tunnel as the engineering background.This model incorporated peripheral boreholes.Various explosives including emulsion explosives,ammonium nitrate explosives,and ANFO explosives were studied for their damage extents around blast holes.The reliability of the numerical simulation was validated using experimental data from EMULEX 80.Finally,combining the on-site analysis of the water diversion tunnel,the impacts of different explosive densities,detonation velocities,and blast pressures on the damage range of the surrounding rock mass near the blast holes were examined.The research findings indicate that in the numerical simulation,emulsion explosives can create cracks at the air line intersections,and the minimum damage range to the surrounding rock by a single blast hole is 47.5 cm.Emulsion explosives demonstrate the best blasting effect within the range of explosive density(1.12~1.14 g/cm^(3)),detonation velocity(4500~5000 m/s),and blast pressure(8000~9000 MPa).Comparing the results obtained from eight field tests,further optimization of the charging structure based on EMULEX 65 and EMULEX 80 emulsion explosives was considered to enhance the economic benefits of on-site construction.The research outcomes offer certain guidance for addressing over-excavation and damage control in the blasting excavation of the water diversion tunnel.