Modern burn cut design

The burn cut, otherwise known as a parallel hole cut, is one of the most commonly used underground blasting methods because it can be used in drifts of all sizes and dimensions. The burn cut has also been tested in almost all rock types and can effectively break weak or strong rocks, depending on the design. In a burn cut round, five different classifications of holes exist that work together to create a round, which pulls effectively, leaves a good contour and is cost-effective. The relief holes used in the burn cut round are one of the most important design criteria for controlling and maximizing the face advance. Two main factors to consider with the relief hole is the diameter or equivalent diameter and the length of the relief hole. These both influence the stress relief of the cut and the distance from the relief hole(s) that the first cut hole will be placed. The second factor that will influence the total pull is the length of the relief hole.