急倾斜薄矿脉中深孔爆破围岩夹制作用机理及定量表征方法  

Mechanism and Quantitative Characterization Method of Rock Clamping Effect in Medium-deep Hole Blasting of Steeply Inclined Narrow Vein Mining

作　　者：王智[1] 安龙[1] 孙星 符洲云 WANG Zhi;AN Long;SUN Xing;FU Zhou-yun(Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang 110819,China;Xihe County Zhongbao Mining Co.,Ltd.,Longnan 742199,China)

机构地区：[1]东北大学深部金属矿山安全开采教育部重点实验室,沈阳110819 [2]西和县中宝矿业有限公司,陇南742199

出　　处：《爆破》2024年第4期61-72,共12页Blasting

基　　金：国家重点研发计划(2022YFC2903802)。

摘　　要：以甘肃某金矿急倾斜薄矿脉为工程背景,针对急倾斜薄矿脉中深孔爆破围岩夹制作用大,矿石贫损大的问题,采用现场调查、PMMA(有机玻璃)爆破模型试验与数值模拟相结合的方法,深入探究了薄矿脉爆破围岩夹制作用机理,提出并建立了围岩夹制作用的定量表征方法。开展PMMA爆破模型试验,分析了薄矿脉不同采幅条件下的爆生裂纹分布规律,结果表明:薄矿脉采幅减小,降低了炮孔周围爆破粉碎区以及破裂区的半径,抑制了爆破裂纹的发育。开展了不同薄矿脉采幅条件下的爆破数值模拟,结果表明:薄矿脉采幅减小,爆破自由面处反射叠加的爆破能量减小,爆破破岩的体积也相应减小,更多的爆破能量以动能的形式散逸不能有效破岩。基于爆破能量分析结果,提出了薄矿脉爆破夹制系数的定量表征方法,即采用半无限工况和窄幅工况下爆破自由面中心点处的总能量峰值之比来定义夹制系数,并用该指标来表征夹制作用的大小,进而通过采幅宽度和岩体力学参数建立了爆破夹制系数预测模型,为急倾斜薄矿脉中深孔爆破参数的优化设计提供了理论依据和技术支持。Since the problems of significant rock clamping effect and ore depletion were caused by deep hole blasting in steeply inclined thin veins,a combination of on-site investigation,PMMA(organic glass)blasting model experiment and numerical simulation was used to explore the mechanism and a quantitative characterization method of rock clamping effect by taking a gold mine in Gansu Province as the engineering background.Firstly,to analyze the distribution pattern of blasting cracks under different mining conditions of thin ore veins,a PMMA blasting model experiment was conducted.The results show that reducing the mining width of the thin ore veins reduces the radius of blasting crushing and fracture areas around the blast hole and suppresses the development of blasting cracks.Furthermore,different blasting conditions of thin ore vein mining were simulated.The results show that as the mining width of thin ore veins decreases,the blasting energy reflected and superimposed at the blasting-free surface decreases,and the volume of blasting rock decreases accordingly.Meanwhile,more blasting energy is dissipated as kinetic energy,which could not be effectively used to break the rock.Finally,a quantitative characterization method for the clamping coefficient of thin ore vein blasting was proposed based on the analysis of blasting energy.A clamping coefficient was defined by the ratio of the total energy peak at the center point of the blasting free surface under semi-infinite and narrow amplitude working conditions,and this index characterized the size of the clamping effect.As a result,a prediction model for the blasting clamping coefficient was established through the mining width and rock mechanics parameters.The study of this paper can provide a theoretical basis and technical support for the optimization design of deep hole blasting parameters in steeply inclined thin ore veins.

关 键 词：急倾斜薄矿脉 中深孔 夹制作用 自由面宽度 定量表征 

分 类 号：TD235.3[矿业工程—矿井建设]