Authors: Stacey, TR


DOI https://doi.org/10.36487/ACG_repo/708_Stacey

Cite As:
Stacey, TR 2007, 'Slope Stability in High Stress and Hard Rock Conditions', 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. 187-200, https://doi.org/10.36487/ACG_repo/708_Stacey

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Abstract:
Open pit mines are being planned to greater depths that will certainly involve high stress and hard rock conditions. These conditions are not satisfactorily accounted for by conventional stability analysis approaches that are based on the common mechanisms of failure involving planar, wedge and circular shear surface, and toppling. Failure mechanisms in high, hard rock slopes are much more complex than this. Progressive failure in hard rock slopes involves initiation and progression of failure along existing weakness planes, and initiation and progression of failure in intact rock. Mechanisms of slope failure behaviour, and the implications for slope stability analysis and slope design, are considered in this paper. It is concluded that what is required for robust stability evaluation and design is much better understanding of the rock mass, and methods of analysis that can model the rock mass and take into account variability in all of the geotechnical parameters. Better site investigations and modern methods of slope monitoring should supply considerable information regarding the understanding of the three dimensional rock mass. Owing to geotechnical variability, data must be expressed in the form of statistical distributions, and methods of stability analysis must therefore be probabilistic rather than deterministic. The output from such analyses will not be a single evaluation, but a distribution of evaluations that will form the basis for a decision on the acceptability of risk of failure. Although the methods required for such analyses are already available in theory, they cannot yet be practically implemented because of lack of computing power. In particular, the requirement that analyses are probabilistic and three dimensional places enormous demands on computing capacity.

References:
Armstrong, R. and Stacey, T.R. (2005) The extent and volume of three dimensional failures in rock slopes in which
several sets of joints define the geological structure. Proc. 3rd Southern African Rock Engineering Symp. Best
practices in rock engineering, Randburg, S. Afr. Inst. Min. Metall., Symposium Series S41, pp. 201-209.
Slope Stability in High Stress and Hard Rock Conditions T.R. Stacey
198 Slope Stability 2007, Perth, Australia
Aydan, Ö., Shimizu, Y. and Ichikawa, Y. (1989) The effective failure modes and stability of slopes in rock mass with
two discontinuity sets. Journal Rock Mechanics and Rock Engineering, Vol. 22, No. 3, Springer Verlag Vienna,
July 1989, pp. 163-188.
Bieniawski, Z.T. (1992) Invited Paper: Principles of engineering design for rock mechanics, Rock Mechanics. Proc.
33rd US Symp. on Rock Mech., Ed. Tillerson & Wawersik, Balkema, pp. 1031-1040.
Brummer, R.K., Li, H. and Moss, A.S.E. (2006) The transition from open pit to underground mining: an unusual slope
failure mechanism at Palabora. Proc. Int. Symp. on Stability of Rock Slopes in Open Pit Mining and Civil
Engineering, S. Afr. Inst. Min. Metall.
Butcher, R.J. (2000) A modelling method for predicting block cave cavability, initial fragmentation and production
tonnage at a scoping study level. MScEng Research Report, University of the Witwatersrand.
Cawood, F.T. and Stacey, T.R. (2006) Survey and geotechnical slope monitoring considerations, Jl S. Afr. Inst. Min.
Metall., Vol. 106, No. 7, pp. 495-501.
Diering, J.A.C. and Stacey, T.R. (1987) Three-dimensional stress analysis: a practical tool for mining problems,
APCOM 87. Proc. 20th International Symposium on Application of Computers and Mathematics in the Mineral
Industries, Vol. 1, Mining, Johannesburg, 1987, S. Afr. Inst. Min. Metall., pp. 33-42.
Dight, P.M. (2006) Pit wall failures on “unknown” structures. Jl S. Afr. Inst. Min. Metall., Vol. 106, pp. 451-458.
Eberhardt, E., Spillmann, T., Maurer, H., Willenberg, H., Loew, S. and Stead, D. (2004) The Randa Rockslide
Laboratory: establishing brittle and ductile instability mechanisms using numerical modelling and
microseismicity. Landslides: Evaluation and Stabilization, Lacerda, Ehrlich, Fontoura and Sayao (eds), Taylor &
Francis Group, London, pp. 481-487.
Grenon, M. and Hadjigeorgiou, J. (2003) Open stope stability using 3D joint networks. Rock Mech. Rock Engineering,
Vol. 36, No. 3, pp. 183-208.
Hoek, E., Rippere, K.H. and Stacey, P.F. (2000a) Large-scale slope designs – a review of the state of the art. In Slope
Stability in Surface Mining, Hustrulid, McCarter & Van Zyl (eds), SME, Colorado, pp. 3-10.
Hoek, E., Read, J., Karzulovic, A. and Chen, Z.Y. (2000b) Rock slopes in civil and mining engineering. Proc.
GEOENG 2000, Invited paper, 16 p.
Hustrulid, W. (2006) Some thoughts regarding mining and rock mechanics. Newsletter Volume 27, Australian Centre
for Geomechanics, December, pp. 1-3.
Ilbury, C. and Sunter, C. (2005) Games foxes play – planning for extraordinary times. Human & Rosseau Tafelberg,
180 p.
Kay, D.R., McNabb, K.E. and Carter, J.P. (1991) Numerical modelling of mine subsidence at Angus Place Colliery.
Proc. Symp. Computer Methods and Advances in Geomechanics, de Beer, Booker and Carter (eds), Balkema,
pp. 999-1004.
Lucas, D. (2006) Stress failure of a shallow open cut mine. Newsletter Volume 27, Australian Centre for
Geomechanics, December, pp. 4-6.
Lynch, R.A., Wuite, R., Smith, B.S. and Cichowitz, A. (2005) Microseismic monitoring of open pit mines. Proceedings
RaSIM6 – Controlling the Seismic Risk, pp. 259-266.
Mercer, K.G. (2006) Investigation into the time dependent deformation behaviour and failure mechanisms of
unsupported rock slopes based on the interpretation of observed deformation behaviour. PhD Thesis, University
of the Witwatersrand.
Merrill, R.H. and Wisecarver, D.W. (1967) The stresses in rock around surface openings. In Failure and Breakage of
Rock, C. Fairhurst (editor), AIME, New York, pp. 337-350.
Moss, A., Diachenko, S. and Townshend, P. (2006) Interaction between the block cave and the pit slopes at Palabora
Mine. Jl S. Afr. Inst. Min. Metall., Vol. 106, pp. 479-484.
Naismith, W.A. and Wessels, S.D.N. (2005) Management of a major slope failure at Nchanga Open Pit, Chingola,
Zambia. Jl S. Afr. Inst. Min. Metall., Vol. 105, pp. 619-626.
Pine, R.J., Coggan, J.S., Flynn, Z.N. and Elmo, D. (2006) The development of a new numerical modelling approach for
naturally fractured rock masses. Rock Mech. and Rock Engineering, Vol. 39, No. 5, pp. 395-419.
Piteau, D.R. and Jennings, J.E. (1970) The effects of plan geometry on the stability of natural slopes in rock in the
Kimberley area of South Africa. Proc. 2nd Int. Cong. Int. Soc. Rock Mech., Belgrade, Vol. 3, Theme 7, Paper
No. 4.
Salim, A. and Stacey, T.R. (2006) Unstable rock slope behaviour in discontinuous rock masses. Proc. Symp. Facing the
Challenges, S. Afr. National Institute of Rock Engineering, Rustenburg, pp. 30-45.
Simmons, J.V. and Simpson, P.J. (2006) Composite failure mechanisms in coal measures’ rock masses – myths and
reality. Jl. S. Afr. Inst. Min. Metall., Vol. 106, pp. 459-469.
Sjoberg, J. (2000) Failure mechanisms for high slopes in hard rock. In Slope Stability in Surface Mining, Hustrulid,
McCarter and Van Zyl (eds), SME, Colorado, pp. 71-80.
Stacey, T.R. (2006a) Design – a Strategic Issue. Proc. 2nd Int. Seminar on Strategic vs Tactical Approaches in Mining,
Perth, Australian Centre for Geomechanics, Section 4, 13 p.
Numerical Modelling of Rock Slope
Slope Stability 2007, Perth, Australia 199
Stacey, T.R. (2006b) Considerations of failure mechanisms associated with rock slope instability and consequences for
stability analysis. Jl. S. Afr. Inst. Min. Metall., Vol. 106, pp. 485-493.
Stacey, T.R., Wesseloo, J. and Bell, G. (2005) Predicting the stability of rockpasses from the geological structure. Jl. S.
Afr. Inst. Min. Metall., Vol. 105, No. 11, pp. 803-808.
Stacey, T.R., Wesseloo, J. and Lynch, R. (2004) “Extension” and seismicity in a hard rock open pit mine. Proc. 2nd Int.
Seminar on Deep and High Stress Mining, S. Afr. Inst. Min. Metall., pp. 41-53.
Stacey, T.R., Terbrugge, P.J., Keyter, G.J. and Yu, Xianbin (2003a) Extension strain – a new concept in open pit slope
stability, and its use in the explanation of two slope failures. Proc. 5th Large Open Pit Conf., Kalgoorlie,
Aus.I.M.M., pp. 259-266.
Stacey, T.R., Xianbin, Y., Armstrong, R. and Keyter, G.J. (2003b) New slope stability considerations for deep open pit
mines. Jl S. Afr. Inst. Min. Metall., Vol 103, No. 6, pp. 373-389.
Stacey, T.R. and Swart, A.H. (2001) Practical Rock Engineering Practice for Shallow and Opencast Mines. SIMRAC,
The Safety in Mines Research Advisory Committee, 66 p.
Stacey, T.R. (1996) Stress analysis and three dimensions in rock slope stability. In Milestones in Rock Engineering,
A.A. Balkema, pp. 173-187.
Stacey, T.R. and Haines, A. (1984) Design of large underground openings in rock - an integrated approach. Proc.
Seminar on Design and Construction of Large Underground Openings, S. Afr. Nat. Committee on Tunnelling,
November 1984, pp. 17-25.
Sweby, G. (2004) WA research examines microseismic emission in open pit mining. Newsletter Volume 22, Australian
Centre for Geomechanics, August, pp. 12-13.
Tarasov, B.G. and Randolph, M.F. (2007) Frictionless shear at great depth and other paradoxes of hard rocks. Int. J.
Rock Mech. Min. Sci, submitted for publication.
Terbrugge, P.J., Wesseloo, J., Venter, J. and Steffen, O.K.H. (2006) A risk consequence approach to open pit slope
design. Jl. S. Afr. Inst. Min. Metall., Vol. 106, pp. 503-511.
Wyllie, D.C. and Mah, C.W. (2004) Rock slope engineering: civil and mining, Spon. Press.
Slope Stability in High Stress and Hard Rock Conditions T.R. Stacey
200 Slope Stability 2007, Perth, Australia




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