Experimental study of blasting vibration with precisely-controlled delay time

To understand the blasting mechanism of electronic detonators in weakening blasting vibration and improving rock fragmentation, a calculation formula was given for the millisecond-delayed time between blasting holes based on the energy change in the process of seismic wave propagation. And the model test was designed and carried out according to the actual open pits in China. The test results show that reasonably controlling the delay times between blasting holes can weaken blasting vibration. In the tests, the instantaneous energy of blasting vibration by the 12-millisecond-delay interval is 19%, 25% and 36% of those by 2-, 7- and 9-millisecond-delay intervals, respectively. The peak velocity of blasting vibration by 4- and 12-milliseconddelay intervalls is around 50% of those by the other delay intervals. And the given calculation formula was applied in an engineering practice and its feasibility was validated.