This report presents a literature survey of destressing and preconditioning practices used in underground mines throughout the world. From the thirty-one references studied, ten mines from Canada, the United States and South Africa were found to practice these techniques in highly stressed pillars, drifts or shafts. Drilling and blasting parameters used at the mine sites are summarized along with the comments and recommendations made by the authors. The review shows that preconditioning the rock mass can be successfully achieved. However, a high degree of risk is associatedwith the empirical approach currently used by mine operators and the results can often be completely opposite to the destressing objective sought.
Further research is recommended for amore rational solution.