Abstract

The design of safe mine excavations requires knowledge of the strains present in the bedrock. Instability around underground mine excavations is responsible for several accidents - some of them fatal - in Québec every year. In light of the difficulty of measuring bedrock strain, a predictive model applicable to the north-western region of Québec - specifically, to the mines located along the Cadillac fault - was developed.

The model is innovative in that it was developed for a specific geological region, which results to better curve-fitting in regression analysis. Another innovative element is that the depth-related variation of constraints was assumed to follow a polynomial rather than linear distribution; this resulted in better correlation of field data and predicted results, while avoiding very high horizontal constraints near the surface. This model was shown to be safer, on average, than current models, in terms of both near-surface structural instability and instability due to excessive constraints at greater depths.