Study on the influence of initiation system on blast induced ground vibration in dragline operations

During blasting, only a small portion of the total available energy of explosive reaction gets consumed in breaking up the rock while most of remaining energy gets dissipated in the form of ground vibration and air overpressure. These side effects of blasting operation not only reduce the powder factor but also prove to be a nuisance for the nearby human settlements and structures, both belonging to and not belonging to the owner of the mine. However, to fulfil the expanding production targets of large opencast mines the deployment of high capacity machines and consequent requirement of deep hole blasting with high amount of explosive consumptions is obvious. In such circumstances, the evaluation of the ground vibration parameters and development of new controlled blasting designs are the needs of the hour. Choice of better initiation system to reduce ground vibration is a major step in this direction. For this, an experimental study was conducted to understand the influence of initiation system on blast induced ground vibrations. In the study, 21 production blasts - 10 using detonating fuse and 11 using electronic detonators, were monitored for ground vibration measurement. The blasts were conducted at the dragline benches of Jayant opencast project. The results obtained from the study revealed that the percentage reduction in ground vibration levels, by using electronic detonators instead of detonating fuse, ranges from 33% to 9% for varying distance from the blast site ranging from 100 m to 1500 m