弓长岭铁矿巷道掘进掏槽孔超深长度优化试验研究

巷道钻爆法掘进中，掘进速度的关键在于掏槽。为了研究金属矿山巷道掘进过程中掏槽孔超深与炮孔利用率的关系，基于20世纪90年代以来部分相关文献资料以及开展的掏槽孔超深现场试验成果，探讨了掏槽孔相对于其他炮孔超深长度的合理取值范围。研究结果表明：无论是在金属矿山还是非金属矿山，随着巷道掘进工程量的不断扩大，炮孔深度逐渐增大，但掏槽孔超深长度并没有改变。根据部分金属矿山掏槽超深的数据统计，95.2%的金属矿山掏槽超深长度基本保持在200 mm及以下。基于掏槽孔超深现场试验，在保证其他参数不变的前提下，以掏槽孔超深长度作为单一变量，当辅助孔和周边孔炮孔深度分别为1.8 m和2.0 m时，掏槽孔对应的最优超深分别为300 mm和400 mm，获得的炮眼利用率极值为97%和95%，较超深长度200 mm时分别提高了5.4%和10%，掏槽孔超深长度的变化对炮孔利用率有重要影响。基于掏槽孔超深长度优化问题，引入超深系数η]概念，当辅助孔和周边孔深为x时，掏槽孔对应的孔深为y，存在最优掏槽孔超深系数η]，使得炮眼利用率最高。

Experimental Study on the Ultra-deep Length Optimization of the Excavation Cutting Holes in the Tunnel of Gongchangling Iron Mine

Cutting is the key to dring speed in tunnel drilling and blasting.In order to study the relationship between the ultra-depth of cutting hole and the utilization rate of hole in the tunneling process of metal mine，the reasonable value range of the ultra-depth of cutting hole and other holes was discussed based on some relevant literature since 1990s and field test results of the ultra-depth cutting hole.The study results show that whether in metal mines or non-metal mines， with the continuous expansion of tunneling engineering quantity，the depth of hole gradually increases，but the ultra-depth of cut hole does not change.According to the statistics of the ultra-deep cutting of some metal mines，95.2% of the metal mines' roadway blasting and excavation under 200 mm. Based on the field test results of cutting hole ultra-deep，under the premise of keeping other parameters unchanged，the ultra-deep length of the cutting hole is used as a single variable，it is concluded that the auxiliary hole and the surrounding hole are 1.8 m and 2.0 m respectively，and the optimal ultra-deep corresponding to cutting hole is 300 mm and 400 mm respectively， which gets the extreme value of hole utilization 97% and 95%， and increased by 5.4% and 10% when compared to the ultra-deep length of 200 mm，the variety of the ultra-deep length of the cutting holes has an important influence on the utilization rate of the holes.Aming at the optimization problem of overdepth length of cutting hole，the concept of overdepth coefficient η] is introduced，when the depth of the auxiliary hole and the surrounding hole is x， the corresponding hole depth of the cutting hole is y，and there is an optimal cutting hole ultra-deep coefficient η]，which makes the utilization rate of the blasthole highest.