A numerical modelling case study - correlation of ground support instrumentation data with a three dimensional inelastic model

As a sub-project of the industry-sponsored initiative GSSO (Ground Support Systems Optimisation Project) being delivered by the Australian Centre for Geomechanics (University of Western Australia), a numerical modelling exercise has been carried out using ground support instrumentation and rockmass data acquired at George Fisher Mine (part of Glencore’s Mount Isa Mines operation) in Mount Isa, Queensland, Australia. The aim of the modelling was to attempt to correlate field measurements with model results, using a commercially available numerical modelling package with realistic rockmass parameters. The over-arching aim of the project is to assess the limits of applicability of numerical modelling in ground support system design. The three dimensional inelastic code FLAC3d (Itasca) was selected due to its capability to model a realistic mine-wide geometry while providing sufficient detail in the instrumentation sites' areas of interest. Flac3d also has the constitutive models and support element formulations which make it possible to incorporate the field measurements acquired during the monitoring campaign. Results in terms of excavation closure, cable loads and fibrecrete load correlation are presented and discussed. Implications for ground support system design are raised.