Optimization of large-diameter deep-hole stope blasting technology based on numerical simulation: a case study of the Dongguashan copper mine

In large-diameter deep-hole blasting operations for mining stopes, optimizing blasting techniques can enhance ore recovery rates while minimizing damage to the surrounding rock mass. To improve blasting efficiency in the large-diameter deep-hole stopes of the Dongguashan Copper Mine, this study employed numerical simulations to evaluate the impact of various bore-hole parameters and charge structures on blasting outcomes. First, by comparing stress wave distributions and peak pressures for boreholes of different diameters, and analyzing crater formation patterns for different row and borehole spacing configurations, the optimal borehole net-work parameters for 165 mm boreholes with non-coupled charge structures were determined. Subsequently, edge-hole blasting models were developed using radial non-coupled and axial spaced charge methods under different blasting schemes. Finally, the damage characteristics of ore pillar rock masses were examined through damage contour maps and stress curves for different edge-hole charge structures. Key findings indicate that increasing the radial non-coupling coefficient reduces peak stress and stabilizes equivalent stress at monitoring points, minimizing damage to ore pillars. Additionally, axial charge structures with optimized charge density and segment length significantly improve boundary control by reducing the damage radius. These results establish optimized borehole and charge configurations, achieving a balance between efficient fragmentation and minimal ore loss.The findings have practical implications for improving blasting designs in underground mines, particularly under high-stress conditions, and provide a basis for future research on advanced blasting techniques with enhanced energy efficiency and minimal environmental impact.