摘要
针对我国北方某大型露天矿节理裂隙发育含水岩体边坡控制难题,从理论计算、模型试验和现场试验角度开展了预裂爆破系统研究。通过理论推导分析,分别得到了干孔和水孔条件下预裂孔孔壁压力的计算公式,得出了孔壁压力与当量不耦合系数之间的关系曲线,确定了预裂孔距的计算公式,为现场试验参数选择提供了理论依据。预裂孔孔壁压力与当量不耦合系数Kd呈负指数关系;在当量不耦合系数相同时,水介质孔壁压力皆大于空气介质的孔壁压力。有机玻璃(Polymethyl Methacrylate,PMMA)模型试验结果显示,水介质预裂爆破有助于提高炸药能量利用率,形成较好的定向预裂缝。现场试验表明:水介质预裂爆破延长了爆破作业时间,在同等条件下,水介质预裂孔距可比空气介质时减小约10%,线装药密度相应减少10%~15%;同时合理的预裂孔距应控制在1.3 m以内,以保证较好的预裂爆破效果。研究结果对于类似矿山预裂爆破作业具有一定的参考价值。
In view of the problem of slope control of water-bearing rock mass with joint and crack development in alarge open-pit mine in the north of China,the research of pre-split blasting was carried out from the perspective of theoreticalcalculation,model test and field test.Through theoretical derivation and analysis,the calculation formulas of pre-splitting porewall pressures under dry and water pore conditions were obtained,and the relationship curve between pore wall pressure andequivalent uncoupling coefficient was obtained.It provides theoretical basis for field test parameter selection.The pre-splittinghole wall pressure has a negative exponential relationship with the equivalent uncoupling coefficient Kd.With the same Kd,thepore wall pressure of the water medium is greater than the pore wall pressure of the air medium.Polymethyl methacrylate(PM-MA)model test results show that pre-splitting blasting in aqueous media helps to improve the energy utilization rate of explo-sives and form better directional pre-fractures.Field tests show that pre-splitting blasting in aqueous media prolongs blastingoperation time,under the same conditions,the distance between the pre-cracked holes in the water media decreases by about10% compared with that in the air media,and the density of the wire charge decreases by 10%~15% correspondingly.At thesame time,the reasonable pre-splitting blast hole distance should be controlled within 1.3 m to ensure better the pre-splitblasting effect.The research results can provide reference for the pre-split blasting operation of the similar mines.
作者
刘为洲
Liu Weizhou(Sinosteel Maanshan General Institute of Mining Research Co.,Ltd.,Maanshan 243000,China;State Key Laboratory of Safety and Health for Metal Mines,Maanshan 243000,China)
出处
《金属矿山》
CAS
北大核心
2020年第2期169-176,共8页
Metal Mine
关键词
预裂爆破
孔壁压力计算
有机玻璃模型试验
现场试验
Pre-split blasting
Hole wall pressure calculation
Test of polymethyl methacrylate model
Field test
