Violent stress relief of pillars due to blasting at Macassa Mine, Canada

The geological setting of the Macassa Mine is similar to other gold mines in the Canadian Pre-Cambrian Shield, where quartz veins are localized in silicified and car-bonatised rocks. The silicified rocks and quartz veins are mainly of elastobrittle behaviour, with ability to store seismic energy with a possibility of its sudden release. The distribution and concentration of primitive stress in a rock mass in some instances could influence or contribute to a rock burst phenomena. The mining stresses composed by the integration of static and dynamic stresses, however, are the main factor of mine instabilities, either non-violent rock fall or rock bursts. This paper gives a main consideration to rock barst phenomena in regards of production blasting, which is considered as a main factor of its triggering.