露天矿山边坡预裂爆破导向空孔技术研究及应用

Research and Application of Guided Empty Hole Technology for Presplitting Blasting in Open-Pit Slope

针对露天矿山边坡预裂爆破,建立导向空孔爆破计算模型,分析导向空孔孔径、装药炮孔不耦合系数、装药炮孔与导向空孔孔距对预裂爆破效果的影响。针对别斯库都克露天煤矿的边坡预裂爆破,根据现场已有设备型号,确定预裂孔和导向空孔孔径为120 mm,最佳不耦合系数为1.5,开展装药炮孔与导向空孔不同孔距下预裂爆破试验,对保留岩体预裂成缝、半孔率及平整度进行综合评价,得到孔距为2.2 m时,预裂缝成型好,保留岩体的损伤程度最小,边坡半孔平均成型率达到87.6%,边坡壁面光滑,根底情况良好,无浮石、碎石,取得了较好的边坡成型效果,提高了边坡保留岩体的稳定性,可供类似工程参考借鉴。

Aiming at the presplitting blasting of slope in open-pit mine,a calculation model of guided empty hole blasting was established.The influences of the guided empty hole,the decoupling coefficient of charging hole and the distance between charging hole and guided empty hole on presplitting blasting effect were analyzed.Focusing on the presplitting blasting of the slope of Beskuduk Open-pit Coal Mine,according to the existing equipment type on the site,the sizes of presplitting hole and guided empty hole were determined to be 120 mm,and the optimal decoupling coefficient was 1.5.The presplitting blasting tests under different hole spacing of charging hole and guided empty hole were carried out,and the comprehensive evaluation of the presplitting crack formation,half hole rate and flatness of the reserved rock mass was carried out.When the hole spacing is 2.2 m,the presplitting crack is well formed,the damage degree of the reserved rock mass is the minimal,the average forming rate of the half hole in the slope reaches 87.6%,the slope wall is smooth,the foundation is in good condition,and there is no pumice and gravel.A good slope forming effect has been achieved and the stability of the reserved rock mass of the slope has been improved,which can be used for reference for similar projects.