The influence of constitutive model selection on predicted stresses and yield in deep mine pillars - A case study at the Creighton mine, Sudbury, Canada

Based on recent advances in modelling the post-yield behaviour of brittle rock, the authors have developed a calibrated inelastic model of the 7,910 level (2.4 km depth) at the Creighton Mine in Sudbury, Ontario, Canada using data collected from the monitoring of pillar dilatancy. While this calibrated model represents a state-of-the-art continuum approach for capturing the progressive development of yield and stresses in mine pillars, alternative state-of-practice approaches (elastic and perfectly plastic material models, for example) represent potentially acceptable options for practical application.
The purpose of this study is to examine the influence of constitutive model choice on stress paths throughout the pillar system at the mining level of interest. The strengths and limitations of various material models are compared and contrasted. Elastic models are shown to adequately represent the larger scale pillar system behaviour from a stress transfer perspective, whereas the state-of-art brittle modelling approach is shown to be ideal for understanding specific pillar-scale stresses and yield.