Engineering Application Research On Influence Of Charge Structure On Pre-cracking Blasting Effect

In open pit blasting operations,pre-splitting blasting technology is widely used because it can form cracks with a certain width before detonation in the main blasting area to prevent rock mass destruction in the reserved area.There are many factors affecting the effect of pre-splitting blasting.The charging structure is one of the key factors affecting the effect of pre-cracking.The reasonable charging structure will directly accelerate the efficiency of blasting operations and improve the economic benefits of mines.In engineering applications,in order to overcome the clamping force of the bottom rock and strengthen the crack penetration of the pre-cracked surface,it is usually realized by means of reinforcing the bottom of the pre-cracked hole.Relying on the pre-cracking blasting construction of the limestone mining area of Jiangxia East Cement Co.,Ltd.,based on the existing rock breaking mechanism and pre-cracking blasting mechanism at home and abroad,the factors affecting the seam formation in pre-splitting blasting are analyzed,and the bottom reinforcement is proposed.The effect of the drug on the effect of pre-splitting blasting.Based on the theory of pre-splitting blasting parameter design,the parameters of bottom-enhanced charging were optimized.Different pre-cracking holes and line charge density were designed.The pre-cracking effect and blasting cost were compared and analyzed by field test method.The effect of the charge structure on the pre-cracking effect.The main contents of the research in this paper are as follows:(1)Review a large number of domestic and foreign pre-splitting blasting and charge structure related research data,and elaborate the rock blasting mechanism,pre-crack blasting mechanism and the factors affecting the seaming,and use this theoretical analysis as a guide.Crack blasting parameters are designed and optimized.(2)In the engineering application,the compressive strength of limestone ore in the process application of Jiangxiadong Cement Co.,Ltd.is greater than 100 MPa,thelooseness coefficient is 1.98,the joint fissure is not developed,and the stability of the rock formation is excellent.In order to compare and analyze the pre-cracking effect of different pre-cracking parameters,four sets of blasting tests were designed to determine the best pre-splitting blasting effect when the pre-cracking hole spacing is 2m and the line charging density is 2kg/m.Most economical.It provides a good blasting plan for the large-scale blasting of the mine in the future.(3)From the field effect of blasting,the pre-split hole bottom is used to strengthen the charging structure.The reasonable parameter design and the optimized detonation network have achieved good blasting effect,which has achieved the expected effect of changing the charging structure.