The Analysis of Strainbursts in the Sudbury Region And Numerical Modelling of Destress Blasting

Abstract

The practice of destress blasting to reduce the risk of strainbursting in mines has been used since the early 1950's. Understanding both the variability in causes of strainbursting and the method by which destress blasting could reduce its risk, will allow future researchers to develop better guidelines for destress blasting. This research examines records of strainbursts at three mines near Sudbury, finding that the current method of recording these events yields little information with a large amount of variability dependent on many factors. Significantly, a large proportion of the events had workers at the face at the same time as the events occurred, continuing to highlight the safety risk presented by strainbursting. In-situ trials were also completed, with numerical modelling finding that destress blasting could both increase and decrease stresses in the rock mass depending on the placement and damage zones of the explosive charges.