Crushing Law of Rocks in the Area Near Blasting Source under Ultra-High Pressure

Addressing the engineering challenge where excessive rock fragmentation in the area near blasting source leads to over 50% energy loss of explosives, this study conducts an in-depth experimental investigation into the mechanism of rock over-fragmentation under ultra-high pressure conditions. Using granite as the research subject, soft-recovery techniques were employed to collect fragmented granite samples from the near-blasting area under varying pressures. Statistical analysis of micron-sized fragment distribution under ultra-high pressure was performed via an interactive machine learning-based image segmentation tool, with a focus on elucidating elastoplastic transitions in granite under different loading pressures and energy distribution during fragmentation. The results reveal that ultra-high pressure in the near-blasting area induces complex fracture phenomena in granite. Experiments demonstrate a shift from stepped fracture patterns to micro-cracking characteristics with increasing pressure, indicating that fragmentation energy accounts for no more than 23.68% of the total impact energy at 5.50 GPa. As impact pressure rises, rock fragment size decreases significantly while the proportion of fragmentation energy declines substantially. This research provides theoretical support and practical guidance for high-fidelity simulation of blasting processes and optimized blast design