Model calibration and seismic potential vulnerability assessment with the mining rock mass seismicity model

Authors: Lachenicht, R; Sharrock, G

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DOI https://doi.org/10.36487/ACG_repo/2465_50

Cite As:
Lachenicht, R & Sharrock, G 2024, 'Model calibration and seismic potential vulnerability assessment with the mining rock mass seismicity model', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, pp. 793-808, https://doi.org/10.36487/ACG_repo/2465_50

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Abstract:
The mining rock mass seismicity (MRS) model establishes modelled versus observed seismic potential correlation relations used to forecast the future rock mass seismic response to mining. ITASCA’s FLAC3D continuum code calculates the plastic work dissipated throughout the rock mass and along geological structures for each mining extraction increment of a global mine model. The progressive failure and disintegration of the rock mass is modelled with different FLAC3D constitutive models. The understanding of the rock mass and geological structural environment in conjunction with available calibration data forms the foundation of the seismic potential assessment. Confidence associated with the derived calibration relations reflects the understanding and definition of the failure mechanics incorporated into the modelling. This paper extends the MRS model calibration and seismic potential assessment methodology through the incorporation of modelled system response tests to assess the global system’s vulnerability to failure. Strength assumptions are lowered during a model system test, reducing the analysis reliance on the accuracy of the input parameter assumptions. Spatial and temporal comparisons between the base modelled system response, modelled system tests and observed seismicity are used to refine the modelled seismic potential of failure regions. Failure responses identified from modelled calibration system tests can be integrated back into the baseline model, improving the derived calibration relations and model confidence. System tests are further applied to forward analyses to examine the ongoing system vulnerability to failure. The introduction of system tests with bracketing parameter ranges reduces the model reliance on deterministic input parameter assumptions, facilitating the incorporation of additional mitigation strategies for identified system test vulnerabilities associated with a high modelled seismic potential.

Keywords: seismicity, model calibration, seismic potential assessment

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