切缝药包光面爆破裂纹扩展时空演化分析

Numerical Analysis of the Slotted Cartridge Blasting Crack Extension by Temporal-spatial Evolution

光面爆破机理复杂,裂隙演化具有不确定性,现场试验难以完整观察到炮孔间裂纹的起裂、扩展至贯通。采用CAD与ANSYS联合建模技术构建空气不耦合光面爆破数值模型,运用显式动力分析软件LS-DYNA定义岩石单元失效计算获得切缝药包光面爆破裂纹扩展演化过程,从时空演化角度研究光面爆破裂纹扩展规律,从而为矿山巷道爆破工程提供更精确的指导。研究结果表明:1)CAD与ANSYS联合建模技术弥补了ANSYS对于复杂模型构建的缺陷,实现精确耦合数字建模;2)定义岩石单元失效方法可以使得爆破裂纹演化过程更为直观,切缝药包爆破相较一般空气不耦合装药结构爆破,炮孔周壁产生的径向裂纹和分叉裂纹显著减少;3)模拟不耦合系数1.5、1.8、2.25切缝药包光面爆破裂纹扩展时空过程,发现切缝药包爆破裂纹扩展演化规律,其裂隙数量随着不耦合系数的增大而减少,裂纹扩展演化长度也随之变短,分叉裂纹扩展演化明显降低,当不耦合系数为1.8时,数值模拟切缝药包爆破裂纹扩展演化形成较佳的贯通裂纹,获得较好的爆破效果。

Based on the complexity and uncertainty of smooth blasting,it is difficult to observe the blasting crack by the crack initiation,extension and transfixion through the field test.The model of smooth blasting that air as coupling medium is established by combining CAD with ANSYS.The explicit dynamic analysis software LS-DYNA is used to simulate the slotted cartridge blasting crack extension with the defined elements failure,to provide more accurate guidance for mine laneway blasting projects from the aspects of temporal and spatial evolution with multidirection cutaway views.The research results show that:1)joint modeling with CAD and ANSYS can fill the gap of ANSYS for complex model modeling,and achieve refined digital modeling for roadway;2)blasting crack extension is more intuitive with elements failure being defined,and which has contributed to the analysis of cutting effect.The blast-induced crack surrounding the hole and crack bifurcation are significantly reduced,when slotted cartridge blasting is compared with the model of smooth blasting that air as coupling medium;3)through the temporal and spatial evolution simulation of slotted cartridge when the decoupling coefficient is 1.5,1.8,2.25,respectively,it is found that the number of slotted cartridge blasting crack reduces with the increase of decoupling coefficient,the crack extension length becomes shorter,and the bifurcation of crack extension significantly decreases;When the decoupling coefficient is 1.8,the numerical simulation of slotted cartridge blasting crack extension forms a better transfixion crack evolution and obtains good blasting effect.