Document Type

Conference Paper

Publication Date


Publication Details

Nick Gordon, Geotechnical Aspects of Place Change Mining at Ensham, in Naj Aziz and Bob Kininmonth (eds.), Proceedings of the 16th Coal Operators' Conference, Mining Engineering, University of Wollongong, 10-12 February 2016, 151-165.


The Ensham bord and pillar mine in the central part of the Bowen Basin is developing panels in the 5-6 m thick Aries/Castor Seam, using the place change mining method. The development mining height is typically 3.5 m, with the remaining floor coal and bell outs extracted on retreat. The depth of cover ranges from 45 m up to 150 m. In geologically unstructured areas, low-density roof support patterns are installed due to the competent roof conditions provided by the high ash, roof coal. Ensham is currently producing at an average rate of 0.96 Mtpa from each of the three development units. To achieve these levels of productivity, optimisation of the geotechnical design aspects of the mine including the ground support, pillar dimensions, panel orientation, selection of mining horizon, mining at shallow depths of cover and drivage through fault zones has been necessary. This is supplemented with regular inspections and ongoing assessment of the geological and geotechnical conditions, as development progresses into new mining areas.