Research Outputs (Mining Engineering)

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For information on accessing School of Mining Engineering Research Articles content please contact : Salome Potgieter by email : salome.potgieter@wits.ac.za or Tel : 011 717 1961

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Start date: 2018End date: 2018

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    Towards safer mining: Scientific measurement approaches that could be applied for imaging and locating the buried container lamp-room at Lily mine.
    (The Southern African Institute of Mining and Metallurgy., 2018-02) Hussain, I; Cawood, F.T.; Ali, S
    When the crown pillar at Lily mine collapsed on 5 February 2016, a lamp-room in a container on surface was engulfed in the sinkhole that formed, trapping three miners who were in the lamp-room at the time. In situations like this, it is imperative to locate and rescue the missing miners before the window of opportunity to find them alive closes. The Wits Mining Institute (WMI) at the University of the Witwatersrand was requested to assist with suggestions, and a conceptual study was undertaken to identify techniques that were likely to be successful. Several techniques that have the potential to locate the position of the container were identified, but the typical noise in the form of steel objects, mine cavities, and a combination of broken and solid rock in a complex geographical and geomechanical environment will pose significant challenges.
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    Determination of stable spans in UG2 excavations.
    (The Southern African Institute of Mining and Metallurgy., 2018-05) Watson, B.P.; Gerber, R.
    The hangingwall of the UG2 Reef is characterized by stratification in the form of thin and weakly cohesive chromitite stringers that can vary in number and height above a stope. These stringers, in conjunction with shallow-dipping thrust faulting, endemic across the platinum-bearing reefs of the Bushveld Complex, affect the maximum span that can be safely mined. The paper describes the research that was carried out to determine the interaction of support with the rock mass in both conventional and mechanized workings, and provides insights into stable span determination where excavations are intersected by a shallow-dipping thrust structure. Four important issues are highlighted. 1. Mine pole and pack support has a greater influence on stability than span in the context of the studied database for conventional mines. 2. Shallow-dipping discontinuities are a dominant feature in stability analyses. 3. The height of the vertical tensile zone does not restrict the fallout height if persistent shallow-dipping structures are present. 4. In the context of the numerical modelling shown in the paper, a span of 6 m is safe when 1.8 m long, full-column resin bolts are used at a support resistance of 48 kN/m2, regardless of the k-ratio or height of the triplets (intersections must be dealt with separately). Several leading practices have been developed in recent years to identify and timeously support hazardous structures.