RESEARCH ON BLASTING EXPERIMENTS OF 4.9 METERS LONG-HOLE PYRAMID CUT IN VERTICAL SHAFT

With the geological condition of hard rocks,the efficiency of blastholes in driving blasting of vertical shafts was low,and it could not meet the needs of project.Through researching the theory of blasting and explosion dynamics,using the technology of pyramid cut blasting,the basic parameters of the 4.9 meters long-hole pyramid cut blasting were obtained.The nine field tests had got a very good effect,the number of drilling and the consumption of explosive materials were reduced,the efficiency of blastholes was improved to meet the needs of project.The tests also showed that the flying rocks could be controlled by using reasonable unit explosive consumption of pyramid cut.