Numerical Analysis And Application Research Of Slotted Cartridge Blasting

The large dimension rock blasting is normal blasting technology in waterconservancy and Hydropower Engineering. According to the large dimension rockblasting qualified rate of normal blasting is not high.，Carrying out simulation andapplication research of slotted cartridge blasting has great practical economicsignificance.The thesis relies on the large dimension rock blasting of Dam Complex ofUpper Atbara project of Sudan. Basing on mohaupt principle of slotted cartridgeblasting was analyzed by theoretic and the mechanism of slotted cartridge blastinglarge dimension rock was macroscopically described in the thesis. Numericalsimulation was applying to studying slotted cartridge blasting and the mainparameters influencing the Cumulative effect of slotted cartridge. The slottedcartridge blasting was applied to the engineering field mining large dimension rocktest research. The following are the results of the study：(1) The mahout effect of slotted pipe will change the holes stress distributionafter the slotted cartridge is ignited. The energy of slit direction will be Enhance, atthe same time, the energy of non slit direction will be weakened. When we use thisblasting method, adjacent boreholes will form interconnected long fracture and limitthe development of other direction fracture. As a result, the slotted cartridge blastingis applicable to mine large dimension stone.(2) Numerical simulation slotted cartridge blasting. Through studying thedevelopment and distribution of the holes pressure distribution and the surroundingrock effective stress field, we found that: The air pressure peak of slit direction isgreater than the air pressure peak of non slit direction. To the slit direction, theeffective stress peak of the rock in the range of1.5m exceeds its dynamic tensilestrength. To the non slit direction, the effective stress peak of the rock in the range of0.5m exceeds its dynamic tensile strength and the effective stress peak of the rockoutside the scope of0.5m is lower than its dynamic tensile strength.(3) Research the influence of mahout effect on the slotted cartridge structureparameters. The studying shows that: the kerf width and non coupling coefficient istoo small or too large are not conducive to the slot cartridge produce mohaupt effect.In contrast, when the slit width is10mm and non coupling coefficient is1.5the slotcartridge has better mohaupt effect. (4) Field test. The slot cartridge blasting technology was applied to field testblasting large dimension rock. In the same blasting parameters，the average rate oflarge dimension stone of normal charging structure blasting is32.27%and theaverage rate of large dimension stone of slotted cartridge blasting is54.5%. Whenthe kerf width is10mm，the large dimension rock qualified rate of slotted cartridgeblasting is highest in good agreement with the numerical simulation results.The research shows that the mahout effect of slotted pipe will change the holesstress distribution after the slotted cartridge is ignited. Application of slottedcartridge blasting mining large dimension stone has a good effect, providing a newway for t large dimension stone blasting optimization.