Research And Application Of Stope Outside Controlling Blasting Technique

This paper discusses stope outline controlling blasting technique research situation from the engineering pre-splitting blasting and Smooth blasting operation, then expounds the rock controlled blasting theory and the mechanism research of pre-splitting fissure into seam.Viewing from the dynamic point of the blasting of ore crushing,it's qualitatively explained blasting fragmentation process, and quantitatively calculated of the extent of blasting damage. It's provided a theoretical basis for protecting the stability of stope outline rock and selecting controlled blasting parameters.According to the overall analysis controlled blasting parameters theoretical calculation and selecting experience,it's obtained the initial impacting pressure of hole wall and the smallest decoupling coefficient theoretical values which ensure the hole wall rock is not crushed by the hole wall pressure.It's got the calculation formula of best wave impedance as decoupling charge,and it's provides adopt stope outline controlled blasting method through research.It's got a number of physical and mechanical parameters of the footwall rock mass and orebodies through the rock mechanics experiments,and it's fitting out JWL state equation of each parameter of 2 rocks emulsive explosives using 1stOpt software.Established 16 group presplit blasting seaming model, on this basis it's fitting out presplit blasting line charge density formula through five groups good parameter of presplit blasting effect.Using ANSYS/ls-dyna software established comparison model between coupling propellant and decoupling charge, the hole wall unit minimum principal stress peaks of coupling propellant is 3.344 times than the decoupling charge corresponding unit's.It's illustrated that using decoupling charge of presplit blasting technology can effectively reduce the explosion pressure of hole wall, and decrease damage of retained rock, which is beneficial to stope outline of security and stability. Through researching on numerical simulation process of the presplit blasting seaming can see that presplitting fissure fracture is developed first from hole wall, but rather the stress wave interference theory thought that the cracks were generated from the midpoint above all, then to two holes direction.It's designed the controlling blasting scheme of stope outline mining, and it's showed that tunneling and slope expansion were achieved good effect through engineering practice. According to the analysis of controlled blasting effect of the first medium-length hole blasting, and it's proposed improvement measures, and the second medium-length hole presplit blasting effect were obviously better than the first.