Ideal stope profile to manage seismicity in deep tabular narrow reef mines

Authors: Rakumakoe, O Download Paper

DOI https://doi.org/10.36487/ACG_rep/1952_22_Rakumakoe

Cite As:
Rakumakoe, O 2019, 'Ideal stope profile to manage seismicity in deep tabular narrow reef mines', in W Joughin (ed.), Deep Mining 2019: Proceedings of the Ninth International Conference on Deep and High Stress Mining, The Southern African Institute of Mining and Metallurgy, Johannesburg, pp. 293-306, https://doi.org/10.36487/ACG_rep/1952_22_Rakumakoe



Abstract:
More regional stability pillars have been introduced in deep narrow reef mining stope designs with an aim of increasing the loading area and reducing the induced stress on the active mining stope faces creating a stiffer loading system. Mponeng mine introduced strike pillars into the conventional sequential grid mining layout in 2014 further reduce an already low extraction ratio. This resulted in a reduction in the overall seismic potency two years later, however, the seismic potency/production graphs remained erratic month on month. Cycle mining practice introduced in 2016 was observed to enable compliance to the inter-panel lead-lag standard however did not reduce the erratic seismic response. Studies into the sources of seismic events has indicated that shear fracturing ahead of the stope face is one of the main seismic sources in deep gold mines. In this paper we illustrate that by establishing an ideal stope profile to manage the formation of the shear fractures, a much more consistent seismic potency/production graph can be achieved.

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