为研究高地应力作用下深孔控制爆破损伤情况及裂隙演化规律,以淮南潘三矿深孔松动控制爆破瓦斯增透为工程背景,通过对控制孔导向、应力波传播及地应力下控制孔周围岩体应力理论分析和数值模拟,结合岩石爆破裂隙分形维数,探讨了高地应力对岩体控制爆破裂隙的演化影响。结果表明:控制孔对爆生裂纹的扩展有一定的定向效果,但深部矿区处所受高地应力会影响该定向效果。当控制孔与爆破孔的连线方向与最大主应力方向一致时,爆破定向效果达到最佳;刚起爆时,控制孔为爆破孔提供自由面,降低最小抵抗线;随着地应力的影响,裂纹扩展方向沿最大主应力方向进一步促进爆破孔与控制孔之间的岩体损伤。最后,通过分析不同地应力状态下爆破裂隙的演化情况和分形维数,建立了裂纹分形维数D与损伤量w的预测模型,能较好地预测高地应力下岩体的损伤程度。

To study the damage and crack evolution of deep-hole controlled blasting under high ground stress, the deep-hole loosening controlled blasting gas permeability increase project of Huainan Pansan Mine is used as the engineering background. The influence of high ground stress on rock controlled blas- ting crack evolution is explored based on the theoretical analysis and numerical simulation of controlled hole guidance, stress wave propagation, and rock stress around controlled holes underground stress, tak- ing into account the fractal dimension of rock blasting cracks. The results show that the controlled hole has a certain directional effect on the expansion of blast-induced cracks, the effect that is affected by the high ground stress in deep mining areas. When the direction of the line connecting the controlled hole and the blasting hole is consistent with the direction of the maximum principal stress, the directional effect of blasting can be optimized; at the beginning of detonation, the controlled hole provides a free surface for the blasting hole, and reduces the minimum resistance line. With the influence of groundstress, the crack expansion direction follows the maximum principal stress direction, further generating rock damage between the blasting hole and the controlled hole. Finally, by analyzing the evolution and fractal dimension of blasting cracks under different ground stress conditions, a prediction model for crack fractal dimension D and damage amount w is established, which can predict the degree of rock damage under high ground stress.