Blast vibration monitoring in opencast mines

Abstract

In this report the blast vibration monitoring techniques is studied. Ground vibration induced by blasting practices in mines has become a serious environmental issue in today’s scenario. Various factors influence the blast vibration being produced from the blasting practices such as the pattern of blasting, drilling pattern, quality and quantity of explosives being used, delay pattern etc. Also the vibration which is being generated by the blasting practices is comprised of two types of waves, body and surface waves. Some of the after blast features are also required to be studied in order to determine the safe blasting practices. Three types of adverse effects are generally associated with the blasting practices, Air blast, Fly rock and Ground vibration, However the amplitude, frequency and duration of the ground vibration is determined by the non-controllable(local geology, rock characteristic and distances of the structure from blast site) and controllable parameters(Charge weight, Delay interval, Type of explosive ,Direction of blast progression, Coupling, confinement, Spatial distribution of charges, Burden, spacing and specification and specific charge). For the purpose of determination of the safe Charge per Delay a number of researchers have given various theories and equations. The feasibility of the CMRI equation is studied in this report. Also there are various equipment’s available globally for measuring the ground vibration and air blast. In the present study Minimate Blaster specification has been studied in detail. All the blasting operations were obtained at different- different distances. According graphs were plotted for the data’s available from the blasting practices and the safe Charge per Delay and Peak Particle Velocity is determined for the mine in accordance with the DGMS regulations.