Establishment of geomechanical risk profiles from inelastic continuum modelling results

Authors: Ouellet, A; Séguineau de Préval, C; Andrieux, P Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2465_45

Cite As:
Ouellet, A, Séguineau de Préval, C & Andrieux, P 2024, 'Establishment of geomechanical risk profiles from inelastic continuum modelling results', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 727-738, https://doi.org/10.36487/ACG_repo/2465_45



Abstract:
The geomechanical risk assessment methodology described in this paper aims to provide a risk ‘road map’ for a given mining sequence. The approach makes use of mine-scale inelastic continuum numerical models. The primary objective of these models is to capture the mining-induced stress, deformation and yielding changes within the rock mass as the mining sequence unfolds. Modelling results are then used to establish geomechanical risk profiles based on mining-induced stress and plasticity criteria. Pre-mining conditions and post-mining states are investigated not only from a geomechanical viewpoint, but also from a production/operational perspective over the mine’s life. The assessment of the conditions just prior to mining is meant to evaluate how challenging mining of a given stope is expected to be. Two types of mining challenges are considered: (i) stopes anticipated to be mined under high stress conditions, and (ii) stopes anticipated to be mined under low /residual conditions (i.e. in relaxed and damaged areas). The assessment of the post-mining conditions around each stope also includes two other types of mining challenges: (iii) unplanned dilution off the exposed surfaces, and (iv) stopes likely to trigger an excessive energy release in the surrounding rock mass. Stope risk ratings for each of these mining challenges are established in terms of the number of tonnes of production (or quantities of metal) likely to encounter these challenges over time; in quarterly intervals, for example. Based on these risk profiles, relevant design adjustments, control procedures and/or monitoring programs can be put in place if, where and when necessary. The methodology can also be used to compare different mining scenarios, methods and sequences.

Keywords: continuum 3D inelastic modelling, geomechanical risk profile, high stress, residual conditions, unplanned dilution, seismicity, life of mine simulations

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