Authors: Le Roux, PJ; Stacey, TR


Cite As:
Le Roux, PJ & Stacey, TR 2008, 'Establishing a Methodology for the Assessment of Remnant Stability Using Recorded Seismic Events on Harmony Mines', in Y Potvin, J Carter, A Dyskin & R Jeffrey (eds), SHIRMS 2008: Proceedings of the First Southern Hemisphere International Rock Mechanics Symposium, Australian Centre for Geomechanics, Perth, pp. 679-691,

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Within the Free State province in South Africa, when mining remnants (tabular blocks of ground), the hazard of exposure to large magnitude seismic events is of great concern. It has been found, however, that damage occurs when the local magnitude of these seismic events, ML ≥ 1.5. When analysing the stress state within the remnant at the time of each seismic event, it has been found that there is a strong correlation between the stress states, which can be described by a Remnant Failure Index (RFI), based on the Mohr–Coulomb failure criterion. To evaluate remnants for possible violent failure, the newly developed RFI enables the practitioner to model proposed mining layouts for the remnant, identify possible areas within the remnant where failure can occur and identify the mining step at which it is expected to happen. This paper discusses a methodology for the assessment of remnant stability using seismic event back-analysis.

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