地下金属矿山扇形孔爆破装药结构优化研究OA

This study develops an optimized fan-hole charging configuration grounded in Livingston's crater theo-ry to resolve the persistent challenges of collar zone over-fragmentation and toe region under-charging in conventional underground fan-hole blasting operations,which frequently generate undesirable oversized fragments.Numerical simu-lations employing LS-DYNA finite element software were performed to optimize fan-hole toe spacing.Through com-prehensive analysis of rock damage zone distribution characteristics under both continuous and decked charging con-ditions,this study demonstrates the superior efficacy of decked charging in damage control,with field experimental re-sults providing conclusive validation.Experimental results demonstrate that while the spaced charging configuration a-chieves comparable fragmentation effectiveness to continuous charging,it significantly reduces rock pulverization near boreholes,thereby minimizing powder mineralization.Implementation of the optimized charging structure yields stope blasting fragments with D20 and D80 sizes of 7.12 cm and 18.52 cm,respectively,with maximum block size rigorously constrained below 28.49 cm and minimal occurrence of sub-5 cm fines.