Damage distribution characteristics and space optimizations of the large-diameter deep multi-holes blasting in thick ore bodies

As a crucial method for mining thick ore bodies, deep-hole blasting provides high production efficiency and low explosive consumption. Its effectiveness is heavily dependent on the optimization of blasting parameters. To refine these parameters, single hole and variable hole spacing multi hole blasting crater tests were conducted in mine tunnels with rock masses exhibiting varying degrees of joint fissure development. The parameters derived from these tests were validated using LS-DYNA numerical simulation software, incorporating field conditions into the analysis. By examining the blasting process, fragment size, damage distribution, and crater test results, the optimal blasting parameters were identified: a blasthole spacing of 1.8 m and a row spacing of 1.7 m. The functional relationship between the specific charge control area and the percentage of various damage distributions has been established, providing the optimal percentage for different damage ranges. These optimized parameters were subsequently applied in field deep-hole blasting tests, which successfully reduced the boulder ratio and enhanced blasting efficiency. This study provides valuable parameters for large-diameter deep-hole blasting in mining and significantly improves the construction efficiency of underground space projects.