Sainsbury, D, Pothitos, F, Finn, D & Silva, R 2007, 'Three-Dimensional Discontinuum Analysis of Structurally Controlled Failure Mechanisms at the Cadia Hill Open Pit', in Y Potvin (ed.), Slope Stability 2007: Proceedings of the 2007 International Symposium on Rock Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 307-320, https://doi.org/10.36487/ACG_repo/708_18
The south wall of Newcrest Mining Ltd’s Cadia Hill Open Pit experienced a multi-bench (60,000 t) failure
during 2006. The observed failure mechanism is a combination of structurally controlled and rock mass failure.
The 3DEC code has been developed by Itasca specifically to study complex failure mechanisms involving large
numbers of explicit structures (joints, faults) that divide a rock mass into blocks. Slip, separation and rotation
along explicit structures can occur, while the individual blocks can also deform and yield.
The following paper details a series of analyses that have been conducted with 3DEC to back-analyse the
observed behaviour of the south wall, which happened when mining was at the 505 RL level. The calibrated
model has subsequently been used to investigate the behaviour of the south wall after mining has progressed
down to the 445 RL level.
Finn, D. (2006) Instability report south wall of the pit, Cadia Valley Operations Internal Memorandum.
Hajiabdolmajid, V. and Kaiser, P.K. (2002) Modelling slopes in brittle rock. NARMS-TAC 2002: Mining and Tunneling
Innovation and Opportunity, Vol. 1, R. Hammah, W. Bawden, J. Curran, and M. Telesnicki (eds). Toronto:
University of Toronto Press, pp. 331-338.
Hoek, E., Kaiser, P.K. and Bawden, W.F. (1995) Support of Underground Excavations in Hard Rock. Rotterdam: Balkema.
Itasca Consulting Group, Inc. (2007) 3DEC (Three-Dimensional Distinct Element Code), Version 4.02. Minneapolis.
Itasca Consulting Group, Inc. (2005) PFC2D (Particle Flow Code in Two-Dimensions), Version 3.1. Minneapolis.
Li, T. (2005) Geotechnical Engineering at Newcrest Mining, Australian Centre for Geomechanics Newsletter, Vol. 25.
Lowther, R. (2007) Geomechanical Instability Report – 475 RL Major Rainfall Triggered Rockfall Event, Cadia Valley
Operations Internal Memorandum.
Sainsbury, D.P. and Urie, R. (2007) Stability Analysis of Horizontal and Vertical Paste Fill Exposures at the Raleigh Mine,
Minefill 2007 – Innovation and Experience. Proceedings of the 9th International Symposium on Mining with
Backfill, Montreal, May 2007, CD Proceedings, Paper No. 2527, CIM, Montreal.
Sjöberg, J. (1999) Analysis of Failure Mechanisms in High Rock Slopes, Doctoral Thesis, Department of Civil and Mining
Engineering, Division of Rock Mechanics, Luleå University of Technology, 1999:01/ISSN: 1402-1544, January.
Three-Dimensional Discontinuum Analysis of Structurally Controlled Failure
Mechanisms at the Cadia Hill Open Pit D. Sainsbury, et al.
320 Slope Stability 2007, Perth, Australia