Experimental Study on Pre-splitting Blasting with Large Diameter Long-hole and Its Application in Non-pillar Continuous Mining

摘要

The experiments were made in concrete to simulate blast in different blasting parameters. Non-pillar continuous mining (NPCM) is regarded as a high-efficiency, high-level and one-step mining technology, which can be divided into two substopes. The pillar between the two substopes, termed as the temporary rib pillar (TRP), excavated by the pre-splitting blasting with large diameter long-hole, is the key structure in the mining method. The effect of pre-splitting blasting was evaluated using blast vibration monitoring, split measuring and surface observations. A set of optimum blasting parameters were calculated by using the theoretical analysis and optimization method, based on the experimental data such as effect of vibration attenuation, split width, average roughness, number of half-hole and hole-path ratio. A temporary rib pillar, which was approximately 5.5 m thick and 30 m long and 48 m high in size, was achieved by applying the experimental results to blasting design of Fenghuangshan Copper Mine. The result of application shows the optimized pre-splitting blasting parameters using simulating experiment are useful in the NPCM.