Experimental study of reducing vibration intensity based on controlled blasting with precise time delay

In order to control blasting vibration and improve rock crushing effect through controlled blasting with precise time delay by using digital electronic detonator, based on the energy distribution theory of explosive charge in rock mass, the calculation formula of reasonable delayed time interval (DTI) between blasting holes was obtained. Combined with production practice in open-pit mine, the digital electronic detonators of Long Xin No.1 and Yi Bo Blasting System were used to design and carry out the similar model test of controlled blasting with precise time delay. Matlab 7.0 was used to do time-energy density analysis on vibration signal. The result shows that, the blasting vibration intensity can be reduced effectively through setting reasonable DTI between blasting holes. In the model test, the peak velocity percentage with DTI of 2 ms are respectively 69%, 76%, 77% and 78% of 1 ms, 3 ms, 4 ms and 5 ms, the energy percentage are respectively 37.3%, 84.5%, 52.6% and 58.4%. Engineering practice shows that, with the blasting parameters at quarry Yan Kou, it is effective to reduce blasting vibration and improve blasting effect with setting DTI as 20 ms; the suggested calculation formula of reasonable DTI between blasting holes is practicable. ©, 2015, China Coal Society. All right reserved.