Influence of Mining Front Configuration and Advance Direction on Stability of Development Drifts in Cave Mining
Kharisova O.D.
Institute of Mining, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia
olgazheltysheva@gmal.com
Keywords: Cave mining systems, development drifts, stresses, strains, stability of drifts, unstable rock mass, stress concentration zone, great depths, mining front configuration, mining sequence
Abstract
The authors address stability of development drifts in deep-level cave mining of ore and enclosing rocks. The principles of mining front advance are reviewed. The FEM-based modeling is carried out as a case-study of the Almaz-Zhemchuzhina chromite deposit characterized by low stability. The variants of the configuration and advance direction of the stoping front were estimated in case of side-to-side and center-to-side mining. The estimation criterion was the overall length of haulage crossdrifts in the zones of the increased compressive stresses. It is found that in the test conditions, the most favorable configuration of the mining front is a straight line as it ensures the minimized length of development drifts in the influence zone of stoping. Moreover, in case of the straight-line front, its advance direction has no essential value. The diagonal front of mining is the least preferable variant as it leads to a considerable increase in the volume of the development drifts to be driven in the stress concentration zone. The obtained results enable sound and reasoned selection of efficient flowsheets of mining in difficult geological conditions.
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