A new perimeter control blast design concept for underground metal/nonmetal drifting applications

This report presents a new concept in perimeter control blasting for underground metal/nonmetal mine drifting applications focusing on the importance of the buffer holes in a blast design. The new blast design concept applies the understanding of radial damage that is caused by the buffer hole column charge. Buffer hole radial damage is defined by a practical damage limit applied to the rock lying between the buffer holes and the perimeter. A favorable comparison was made between five successful controlled blast designs and the concept of practical damage limit. This concept is easy to use and acceptance of the approach would only require mines to conduct trial blasts to test the design theory.