Abstract To reduce the destruction damage of conventional blasting on reserved rock,a new blasting method,namely,directional pressure relief vibration isolation blasting,is proposed and its technical principles are introduced. The test results of hopkinson bar,ultra-dynamic,dynamic caustics,dynamic photoelasticity,level one light gas gun and other tests results show that:this method would make explosion pressure reduced by 30% to 60% on the isolation material side;blasting vibration peak decreased by 32% to 67%;detonation wave would be blocked 46.95% and sound velocity reduced 13.48% on the isolation material side. The primary shear stress of the free surface side is 3.5 times of that on the isolation material side;stress intensity factors are 1 to 2.12 times of that on isolation material side. Engineering practices show that it brings a large number of energy together in free surface,geting a good blasting effect,meanwhile it can reduce the cost of the open pit slope excavation and overexcavation in drifting.
|
|
|
|
|