Air overpressure and noise vis-a-vis detonating fuse

The work of engineers, blasters, and project supervisors is to manage risk associated with excavation and blasting. Drilling and blasting are accepted as the best method of excavation. Presently, this methodology is an ever-increasing challenge, as excavations inevitably occur close to populated areas, with environmental concern for structures and utilities. The significant high magnitude, of blast-induced, inaudible air overpressure (AOP) and audible noise, heard along with ground motion, intensifies the human response. The high velocity of detonation of an explosive, a detonating fuse when used in blasting a round, enhances the magnitude of air overpressure and becomes the main cause for complaint from the people residing near the mine. This paper deals with some experimental blasts where the measurement of AOP was carried out for plaster shooting, detonating a fuse (covered and uncovered) and blasting rounds with NONEL, and detonating a cord system of initiation. In observing a high magnitude of AOP by the detonation of a cord, the authors have experimentally proven that mud capping of the trunk line detonating cord reduces the magnitude of AOP. Considering the theory of momentum and conservation of energy, the authors have put forward a mathematical model to explain the influence of mud capping in reducing the noise caused by the detonation of the cord