Recent advances in burn cut technology : P. Haydon, Tunnels & Tunnelling, 27(6), 1995, pp 42–43

Abstract

This article reports recent advances in burn cut technology, a modern explosive technique used in tunnelling. Changes in current thinking behind burnt cut design have come in response to changes in the accuracy of drills, and the increasing range of explosives available to tunnelling engineers. The article discusses various changes in explosives use and drilling technology that forced a redesign of the burn cut. Traditionally, the shot holes in the cut would be about 150mm from the void hole centre and 240mm from the next hole, but they failed to offer protection to each shot hole from its previous hole. Explosives manufacturer Exchem has designed a new arrangement of holes, which ensures that each charged hole is protected from its neighbour by a void hole. This increases the probabilities of a successful shot and the safe achievement of a longer pull. However, the new design is not superior under all conditions. As mining and tunnelling technologies progress, the burn cut becomes an ever more crucial restraint and consideration in the blasting process. Its technology has had to become more sophisticated and flexible, even though it has had no really revolutionary developments.