轴向不耦合装药爆破下页岩的动态应变分布及损伤分形特征

Dynamic strain distribution and damage fractal characteristics of shale under axial decoupled charge blasting

为研究轴向不耦合装药结构对炸药能量传递和爆破效果的影响,提高炸药能量利用率,增强岩体破碎效果,对页岩爆破进行研究,设置下部装药、中部装药、两端装药和耦合装药4种装药结构,进行爆破模型实验。通过超动态应变测试系统,采用互补集合经验模态分解方法处理试件轴向各测点应变波形,并基于计盒维数理论,计算比较应变变化以及各测点处截面的损伤分形维数,对4种装药结构爆炸能量传播规律进行分析。结果表明:下部装药结构能显著提高炸药能量利用率,延长爆生气体作用时间;下部装药、中部装药和耦合装药结构试件截面的损伤分型维数从上到下先增加后减小,两端装药先减小后增大,其中下部装药结构试件损伤分布最均匀,爆破效果最好。

In order to study the influence of axial uncoupled charge structure on explosive energy transmission and blasting effect,improve the energy utilization rate of explosive,enhance the crushing effect of rock mass,study shale blasting,set up four charge structures of lower charge,middle charge,two end charge and coupling charge,and carry out blasting model experiments.Through the superdynamic strain test system,the strain waveform of each axial measurement point of the specimen is processed by the complementary set empirical mode decomposition method,and the damage fractal dimension of the section at each measurement point is calculated and compared based on the box dimension theory,and the explosion energy propagation law of the four charge structures is analyzed.The results show that the structure of the lower charge can significantly improve the energy utilization rate of explosive and prolong the action time of the explosive gas.The damage classification dimension of the section of the lower charge,the middle charge and the coupling charge structure specimen first increased and then decreased from top to bottom,and the two ends of the charge first decreased and then increased,among which the damage distribution of the lower charge structure specimen was the most uniform and the blasting effect was the best.