Geotechnical analyses for risk management of a large scale failure at Century mine, Northwest Queensland

Three-dimensional analysis of complex anisotropic slope instability at MMG’s Century Mine

“…Wedge and planar failures emerged consistently along Page Creek Fault, which intercepted continuous, undulating bedding planes, oriented within 20° of the strike of the pit slope. Sweeney and Abbott (2015) report that in February 2012, after two months of high rainfall, prism data highlighted that a problem was emerging on the south and West Walls of the pit. A design change was undertaken to contain a large-scale planar failure against Page Creek Fault on the South Wall.…”

“…In conjunction with various forms of characterisation, analysis and monitoring (Kurucuk and Sweeney 2012; Sweeney and Abbott 2015; Salvoni et al 2015a; Salvoni et al 2015b), the modelling results presented herein assisted mine personnel implement a management plan that allowed successful recovery of the ore that was deemed at risk.…”

“…The Century Mine is located approximately 250 km's north-west of Mount Isa, close to the Northern Territory border in Far North Queensland, Australia. For the majority of its life, the mine has been the largest producer of zinc in Australia and the third largest in the world producing approximately 500,000 tonnes of zinc concentrate annually (Sweeney and Abbott 2015). The open pit zinc mine has been developed in a series of cutbacks to a depth of approximately 350 m. Figure 1 illustrates a plan view of the open pit at May 2013 with the various active cutbacks.…”

“…Sweeney and Abbott (2015) report that in February 2012, after two months of high rainfall, prism data highlighted that a problem was emerging on the south and West Walls of the pit. A design change was undertaken to contain a large-scale planar failure against Page Creek Fault on the South Wall.…”