不耦合系数对切缝药包爆生裂纹扩展及分形特征的影响  

Effect of Uncoupling Coefficient on the Expansion and Fractal Characteristics of Bursting Cracks of Slit Packs

作　　者：田栩帆 王正雄 陈浩 万再春 关思 王建国[1] TIAN Xufan;WANG Zhengxiong;CHEN Hao;WAN Zaichun;GUAN Si;WANG Jianguo(Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yuxi Mining Co.,Ltd.,Yuxi 653100,China;Mining Institute of Yunnan Copper Co.,Ltd.,Kunming 650224,China;Yunnan Blast Engineering Technology Co.,Ltd.,Kunming 650101,China)

机构地区：[1]昆明理工大学国土资源工程学院,昆明650093 [2]玉溪矿业有限公司,云南玉溪653100 [3]云南铜业股份有限公司矿山研究院,昆明650224 [4]云南博拉斯工程技术有限公司,昆明650101

出　　处：《有色金属工程》2024年第7期130-137,162,共9页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(52274083);云南省基础研究计划面上项目(202201AT070178)。

摘　　要：为研究切缝药包径向空气不耦合装药爆破下的孔周裂纹扩展和损伤演化规律,采用有机玻璃板(PMMA)介质模拟岩石材料,利用透射式动态焦散线试验系统,研究切缝药包径向不耦合系数为1.14、1.28、1.42、1.71、1.86时孔周爆炸力学行为。结果表明:主裂纹扩展分为两个阶段,第一阶段(0~150μs),在爆生气体和爆炸应力波的作用下,裂纹开裂时刻裂纹扩展速度达到峰值,随即立刻下降;第二阶段(150~330μs),由于反射应力波的作用,裂纹继续扩展直至停止。K=1.71时,爆生主裂纹沿切缝方向扩展距离最长,产生的次裂纹数量最少,左右主裂纹形成夹角近乎水平;K=1.28和1.42时,主裂纹扩展长度和产生的次裂纹数量次之;K=1.86和1.14时,裂纹扩展长度较短,产生的次裂纹数量最多。K大于或小于1.71时,爆炸产生的能量得不到充分利用,爆生主裂纹的扩展速度峰值、动态强度因子峰值小。区域Ⅱ、Ⅲ的分形维数随着径向不耦合系数的增大而减小,变化率相对较大,区域Ⅰ由于靠近爆源,整体的分形维数大,变化率小;K=1.71时,炮孔周围形成的粉碎区损伤变量最小。In order to study the perforation crack extension and damage evolution law under the radial air-uncoupled charge blasting of slit packs,the rock material is simulated with Plexiglas plate(PMMA)medium,and the transmission dynamic focal dispersion line test system is used to study the perforation explosion mechanical behaviour of the slit packs with radial uncoupling coefficients of 1.14,1.28,1.42,1.71,and 1.86.The results show that:The main crack expansion is divided into two stages,the first stage(0—150μs),under the action of the bursting gas and the explosive stress wave,the crack expansion rate peaks at the moment of crack opening,and then immediately decreases;the second stage(150—330μs),due to the action of the reflective stress wave,the crack continues to expand until it stops.When K=1.71,the explosive main crack extends the longest distance along the direction of the slit,produces the least number of secondary cracks,and the angle of the left and right main cracks is nearly horizontal;when K=1.28 and 1.42,the length of the main crack extension and the number of secondary cracks produced are the second longest;and when K=1.86 and 1.14,the length of the crack extension is shorter,and the number of secondary cracks produced is the highest.Radial uncoupling coefficient is greater than or less than 1.71,the energy generated by the explosion is not fully utilised,the peak expansion velocity of the blast-generated main crack,the peak dynamic strength factor is small.The fractal dimension of the RegionⅡ,Ⅲdecreases as the radial uncoupling coefficient increases,the rate of change is relatively large.In the regionⅠ,due to the proximity of the source of the explosion,the overall fractal dimension is large,the rate of change is small.When K=1.71,the formation of the crushed zone around the gun hole damage variable is the smallest.

关 键 词：动态焦散线 切缝药包 裂纹扩展 分形维数 损伤变量 

分 类 号：TD853[矿业工程—金属矿开采]