Coulthard, MA & Holt, GE 2008, 'Numerical Modelling of Mining Near and Beneath Tailings Dam', in Y Potvin, J Carter, A Dyskin & R Jeffrey (eds), Proceedings of the First Southern Hemisphere International Rock Mechanics Symposium
, Australian Centre for Geomechanics, Perth, pp. 341-354.
Two coal mining companies proposed to undertake, respectively, longwall mining beneath an existing tailings dam, and open cut mining adjacent to it. 3D numerical stress analyses, using program FLAC3D, were performed to examine this system, as one component of meeting regulatory requirements. Rock cohesions and tensile strengths from earlier 2D modelling had to be reduced by a factor of five to produce modelled surface subsidence comparable with that observed over previous longwall panels. Those properties were then used in the final models, resulting in predicted factors of safety not less than 1.80 for the open cut walls and for the tailings dam. The longwall panels have since been mined, and the open cut is close to completion, without incident.
Coulthard, M.A. and Dutton, A.J. (1988) Numerical Modelling of Subsidence Induced by Underground Coal Mining. Key Questions in Rock Mechanics, Proceedings 29th U.S. Symposium, P.A. Cundall, R.L. Sterling and A.M. Starfield (editors), pp. 529–536. Balkema, Rotterdam.
Coulthard, M.A. (1992) Distinct Element Modelling of Mining-induced Subsidence - a Case Study. Proceedings Conference on Fractured and Jointed Rock Masses, Lake Tahoe, L.R. Myer, C-F. Tsang, N.G.W. Cook and R.E. Goodman (editors), pp. 725–732, Balkema, Rotterdam.
Coulthard, M.A. (2001) Undermining of an Unlined Tunnel in Rock. FLAC and Numerical Modeling in Geomechanics, Lyon, France, D. Billaux, X. Rachez, C. Detournay and R. Hart (editors), pp. 265–272. Balkema, Rotterdam.
Holla, L. (1987) Design of Mine Workings Under Surface Waters in New South Wales, Proceedings AusIMM, Vol. 292, No. 2.
Holla, L. and Buizen, M. (1990) Strata Movement Due to Shallow Longwall Mining and the Effect on Ground Permeability, Proceedings AusIMM, Vol. 295, No 1.
Holt, G.E. (2003) Auger Stability Studies for Wambo and Whynot Seam Recovery, G.E. Holt and Assoc. Pty Ltd, report to Mining Operation Services Pty Ltd, March.
Itasca (2005) FLAC - Fast Lagrangian Analysis of Continua, version 5.0. Itasca Consulting Group, Inc., Minneapolis.
Itasca (2006) FLAC3D - Fast Lagrangian Analysis of Continua in 3 Dimensions, version 3.1. Itasca Consulting Group, Inc., Minneapolis.
United Collieries Pty Ltd and Wambo Coal Pty Ltd (2006) The North East Cut Tailings Dam and Mining Impacts - Dam Condition and Hazard Management report. United Collieries Pty Ltd and Wambo Coal Pty Ltd, Rev. 1.
Walker, M. (2008) Surface Subsidence Monitoring Data for Longwall Panels 5 and 6, United Colliery. United Collieries Pty Ltd, internal records.