Geotechnical design and uncertainty in residual soil slopes

Authors: Mandisodza, KT; Dunn, MJ

Open access courtesy of:

DOI https://doi.org/10.36487/ACG_rep/1905_29_Mandisodza

Cite As:
Mandisodza, KT & Dunn, MJ 2019, 'Geotechnical design and uncertainty in residual soil slopes', in J Wesseloo (ed.), MGR 2019: Proceedings of the First International Conference on Mining Geomechanical Risk, Australian Centre for Geomechanics, Perth, pp. 475-492, https://doi.org/10.36487/ACG_rep/1905_29_Mandisodza

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
Mining in residual soils is a characteristic of some open pit mines, particularly those mines in the tropical and sub-tropical regions. With residual soils’ prevalence on the earth’s surface almost as common as that of sedimentary rocks (Wesley 2013), mining in such soils requires special understanding of the behaviour and characteristics of the residual soil to determine slope designs that are both safe and economic. Due to the presence of relict structures, and the relatively low strength of the residual soils and weathered rock, design slope angles in these materials should be developed by blending the results of the kinematic assessments of geologic structures with rock mass stability analyses and traditional soil mechanics (Newcomen & Burton 2000). It is thus imperative that geotechnical designs should be site/location-specific and based on soil’s field performance, back-analyses and risk zoning. Understanding the variability of these materials is important for developing robust designs. This paper outlines the different aspects that are to be considered when conducting slope designs in residual soils, and in particular, saprolites, and summarises shear strength data from various mine sites that highlights the uncertainty associated with these parameters.

Keywords: saprolite, residual soils, slope design, uncertainty, variability, reliability

References:
Abrahams, G, Raynor, M & Mandisodza, K 2015, ‘Saprolite Slope Design at the Rosebel Gold Mine’, Proceedings of the 2015 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, The South African Institute of Mining and Metallurgy, Johannesburg, pp. 753–768.
Anderson, MG & Lloyd, DM 1991, ‘Using a combined slope hydrology-stability model to develop cut slope design charts’, Proceedings of the Institute of Civil Engineers, vol. 91, issue 4, part 2.
Aydin, A 2006, ‘Stability of saprolitic slopes: nature and role of field scale heterogeneities’, Natural Hazards and Earth System Sciences, vol. 6, pp. 89–96.
Aydin, A & Duzgoren-Aydin, NS 2002, ‘Indices in scaling and predicting weathering-induced changes in rock properties’, Environmental and Engineering Geoscience, vol. 8, issue 2, pp. 121–135.
Aydin, A, Duzgoren-Aydin, NS & Malpas, JG 2000, ‘A review of igneous and metamorphic saprolites’, Journal of Nepal Geological Society, vol. 22, pp. 11–16.
Bell, FG 2000, Engineering Properties of Soils and Rocks, 4th edn, Blackwell Science, Oxford.
Bieniawski, ZT 1989, Engineering Rock Mass Classifications, John Wiley & Sons, New York.
Bland, W & Rolls, D 1998, Weathering: An Introduction to Scientific Principles, Hodder Education.
Blight, GE 1985, ‘Residual soils in South Africa’, in EW Brand & HB Phillipson (eds.), Sampling and Testing of Residual Soils, A Review of International Practice Technical Committee on Sampling and Testing of Residual Soils, Scorpion Press, Hong Kong, pp. 159–168.
Blight, GE 1997, Mechanics of Residual Soils, A.A. Balkema, Rotterdam.
Brand, EW 1984, ‘Landslides in Southeast Asia: a state-of-the-art report’, Proceedings of the 4th International Symposium on Landslides, addendum 3, Canadian Geotechnical Society, Richmond, pp. 105–106.
Brand, EW, Dale, M & Nash, JM 1986,’Soil pipes and slope stability in Hong Kong’, Quarterly Journal of Engineering Geology and Hydrology, vol. 19, no. 3, pp. 301–303.
Brand, EW & Phillipson, HB 1985, ‘Sampling and testing of residual soils: a review of international practice’, The International Society for Soil Mechanics and Foundation Engineering, Scorpion Press, Hong Kong, pp. 194.
Burton, BT 1998, Earthworks with Wet, Fine-grained Tropical Residual Soils, unpublished Master of Engineering report, University of Alberta, Edmonton.
Carranza-Torres, C & Hormazabal, E 2018, ‘Computational tools for determination of factor of safety and location of the critical circular failure surface for slopes in Mohr-Coulomb dry ground’, Proceedings of Slope Stability 2018, Asociacion Nacional de Ingenieros de Minas and Colegio Oficial de Ingenieros de Minas del Sur, Seville.
Chigira, M, 2001, ‘Micro-sheeting of granite and its relationship with landsliding specifically after the heavy rainstorm in June 1999, Hiroshima Prefecture, Japan’, Engineering Geology, vol. 59, pp. 219–231.
Ching, RKH, Sweeney DJ & Fredlund, DG 1984, ‘Increase in factor of safety due to soil suction for two Hong Kong slopes’, Proceedings of the 4th International Symposium on Landslides, Canadian Geotechnical Society, Richmond, pp. 617–623
Costa, AJ & Fernandes, CEM 1985, ‘Slides in saprolites from gneissic rocks with relict slip surfaces: the B.N.E.D.E.S. case study’, Proceedings of the First International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brazilian Society for Soil Mechanics, Brasilia, pp. 49–55.
Cowland, JW & Carbray, AM 1988, ‘Three cut slope failures on relict discontinuities in saprolitic soils’, Proceedings of the 2nd International Conference on Geomechanics in Tropical Soils, A.A. Balkema, Rotterdam, pp. 253–258.
Deere, DU & Patton, FD 1971, ‘Slope stability in residual soils’, Proceedings of the Fourth Pan American Conference on Soil Mechanics and Foundation Engineering, vol. 1, American Society of Civil Engineers, Reston, pp. 87–170.
De Mello, VFB 1972, ‘Thoughts on soil engineering applicable to residual soils’, Proceedings of the 3rd South-East Asian Conference on Soil Engineering, Southeast Asian Society of Soil Engineering, Hong Kong, pp. 5–43.
Drumright, EE 1989, The Contribution of Matric Suction to the Shear Strength of Unsaturated Soils, PhD thesis, Colorado State University, Fort Collins.
Dunn, MJ 2014, ‘Geotechnical models and data confidence in mining geotechnical design’, Proceedings of the Third Australasian Ground Control in Mining Conference, The Australasian Institute of Mining and Metallurgy, Melbourne, pp. 127–133.
Dunn, MJ 2015, ‘How reliable are your design inputs?’ in Y Potvin (ed.), Proceedings of the International Seminar on Design Methods in Underground Mining, Australian Centre for Geomechanics, Perth, pp. 367–381.
Escario, V & Saez, J 1986, ‘The shear strength of partly saturated soils’, Géotechnique, vol. 36, issue 3, pp. 453–456.
Fredlund, DG, & Rahardjo, H, 1985, ‘Theoretical context for understanding unsaturated residual soil behavior’, Proceedings of the 1st International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, vol. 1, Brazilian Society for Soil Mechanics, Brasilia, pp. 295–305.
Fredlund, DG & Rahardjo, H 1993, Soil Mechanics for Unsaturated Soils, John Wiley & Sons, New York.
Fredlund, DG, & Rahardjo, H 1994, ‘Hillside slope stability assessment in unsaturated residual soils’, Proceedings of the IKRAM Seminar on Geotechnical Aspects of Hillside Development.
Fredlund, DG, Morgenstern, NR & Widger, RA, 1978, ‘The shear strength of unsaturated soils’, Canadian Geotechnical Journal, vol. 15, pp. 313–321.
Gan, JKM & Fredlund, DG 1988, ‘Multistage direct shear testing of unsaturated soils’, Geotechnical Testing Journal, vol. 11, issue 2, pp. 132–138.
Gan, JKM, & Fredlund, DG 1992, Direct Shear Testing of a Hong Kong Soil Under Various Applied Matric Suctions, GEO Report No. 11, Geotechnical Engineering Office, Hong Kong,
Griffith, DV & Lu, N 2005, ‘Unsaturated slope stability analysis with steady infiltration or evaporation using elasto-plastic finite elements, International Journal for Numerical and Analytical Methods in Geomechanics, vol. 29, issue 3, pp. 249–267.
Harr, ME 1996, Reliability-based Design in Civil Engineering, McGraw-Hill, Dover.
Hencher, SR & Martin, RP 1982, ‘The description and classification of weathered rocks in Hong Kong for engineering purposes’, Proceedings of the Seventh South-East Asian Geotechnical Conference, Southeast Asian Geotechnical Society, Bangkok, pp. 125–142.
Hencher, SR & McNicholl, DP 1995, ‘Engineering in weathered rock’, Quarterly Journal Engineering Geology, vol. 28, pp. 253–266.
Hencher, SR, Massey, JB & Brand, EW 1984, ‘Application of back-analysis to some Hong Kong landslides’, Proceedings of the 4th International Symposium on Landslides, Canadian Geotechnical Society, Richmond, pp. 631–638.
Horn, HM & Deere, DU 1962, ‘Frictional characteristics of minerals’, Géotechnique, vol. 12, issue 4, pp. 319–335.
Irfan, TY 1998, ‘Structurally controlled landslides in saprolitic soils in Hong Kong’, Geotechnical and Geological Engineering, vol. 16, issue 3, pp. 215–238.
Irfan, TY 1994, ‘Mechanism of creep in a volcanic saprolite’, Quarterly Journal of Engineering Geology and Hydrogeology, vol. 27, issue 3, pp. 211–230.
Irfan, TY & Woods, NW 1988, ‘The influence of relict discontinuities on slope stability in saprolitic soil’, Proceedings of the 2nd International Conference on Geomechanics in Tropical Soils, A.A. Balkema, Rotterdam, pp. 253–258.
Jefferies, M, Lorig, L & Alvarez, C 2008, ‘Influence of rock strength spatial variability on slope stability’, Proceedings of the First International FLAC/DEM Symposium on Numerical Modelling, Itasca Consulting Group, Inc., Minneapolis.
Lindquist, ES & Goodman, RE 1994, ‘Strength and deformation properties of a physical model melange’, Proceedings of the 1st North American Symposium, Rock Mechanics: Models and Measurements Challenges from Industry, A.A. Balkema, Rotterdam,
pp. 843–850.
Lu, N & Godt, J 2008, ‘Infinite slope stability under steady unsaturated seepage conditions’, Water Resources Research, vol. 44, issue 11.
Lu, N & Likos, WJ 2004, Unsaturated Soil Mechanics, Wiley, Hoboken.
Lumb, P 1975, ‘Slope failures in Hong Kong’, Quarterly Journal of Engineering Geology and Hydrogeology, vol. 8, pp. 31–65.
Lupo, J, Byers, T & Brunhart-Lupo, M 2015, ‘Pit slope design challenges in residual soils and highly weathered rock’, Proceedings of the 2015 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, The South African Institute of Mining and Metallurgy, Johannesburg, pp. 697–712.
Marinos, P & Hoek, E 2000, ‘GSI: a geologically friendly tool for rock mass strength estimation’, Proceedings of GeoEng 2000: an International Conference on Geotechnical & Geological Engineering, Technomic Publishing Company, Lancaster,
pp. 1422–1442.
Martin, D & Stacey, P 2018, Guidelines for Open Pit Slope Design in Weak Rocks, CSIRO Publishing, Collingwood.
Massad, F & Teixeira, HR 1985, ‘Deep cut on saprolitic soils conditioned by relict structures’, Proceedings of the First International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brazilian Society for Soil Mechanics, Brasilia, pp. 381–391.
Massey, JB, Irfan, TY & Cipullo, A 1989, ‘The characterisation of granitic saprolitic soils’, Proceedings of the 12th International Conference on Soil Mechanics and Foundation Engineering, vol. 1, Taylor & Francis, Milton Park, pp. 533–542.
McCarthy, DF 1993, Essentials of Soil Mechanics: Basic Geotechnics, 5th edition, Prentice-Hall International, Englewood Cliffs.
Newcomen, WH, Burton, BT & Geyer, J 2000, ‘Pit slope design challenges in residual soils and weathered rock: background and a case study’, Proceedings of the SME Annual Meeting, Society for Mining, Metallurgy & Exploration, Englewood.
Patton, FD & Deere, DU 1971, ‘Geologic factors controlling slope stability in open pit mines,’ in C Brawner & V Miligan (eds), Proceedings of the First International Conference on Stability, American Institute of Mining, Metallurgical and Petroleum Engineers, New York, pp. 23–47.
Press, F & Siever, R 1994, Understanding Earth, Freeman WH & Co Ltd, New York.
Rahardjo, H, Lim, T, Chang, M & Fredlund, D 1995, ‘Shear-strength characteristics of a residual soil’, Canadian Geotechnical Journal, vol. 32, no. 1, pp. 60–77.
Read, J 2009, ‘Data uncertainty’, in J Read & P Stacey (eds), Guidelines for Open Pit Slope Design, CSIRO Publishing, Collingwood, pp. 213–220.
Read, J 2013, ‘Data gathering, interpretation, reliability and geotechnical models’, in P Dight (ed.), Proceedings of the 2013 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 81–90.
Read, J & Stacey, P 2009, Guidelines for Open Pit Slope Design, CSIRO Publishing, Collingwood.
Renani, HR, Martin, CD, Verona, P & Lorig, L 2018, ‘Probabilistic stability analysis of slopes in highly heterogeneous rock masses’, Proceedings of Slope Stability 2018, Asociacion Nacional de Ingenieros de Minas and Colegio Oficial de Ingenieros de Minas del Sur, Seville.
Rezaur, RB, Rahardjo, H, Leong, EC, & Lee, TT 2003, ‘Hydrologic behavior of residual soil slopes in Singapore’, Journal of Hydrologic Engineering, vol. 8, no. 3, pp. 133–144.
Satija, BS 1978, Shear Behaviour of Partially Saturated Soils, PhD thesis, Indian Institute of Technology, New Delhi.
Schellmann, W 2008, An Introduction in Laterite: Products and Processes of Intensive Rock Weathering, viewed 23 October 2018,
Sowers, GF 1985, Residual Soils in the United States, in Sampling and Testing of Residual Soils: A Review of International Practice, in EW Brand & HB Phillipson (eds.), Scorpion Press, Hong Kong, pp. 183–191.
St John, BJ, Sowers, GF & Weaver, CE 1969, ‘Slickensides in residual soils and their engineering significance’, Proceedings of the 7th International Conference Soil Mechanics and Foundation Engineering, vol. 2, Sociedad Mexicana de Mecanica, Mexico City, pp. 591–597.
Terzaghi, K 1936, ‘The shearing resistance of saturated soils and the angle between the planes of shear’, Proceedings First International Conference on soil Mechanics, vol. 1, pp. 54–59.
The Geological Society 1990, ‘Tropical residual soils: A Geological Society Engineering Group Working Party report’, Quarterly Journal Engineering Geology and Hydrogeology, vol. 23, issue 1, pp. 4–101.
Toll, DG 1990, ‘A framework for unsaturated soil behaviour’, Geotechnique, vol. 40, no. 1, pp. 31–44.
Vargas, M & Pichler, E 1957, ‘Residual soil and rock slides’, Proceedings of the Fourth International Conference on Soil Mechanics and Foundation Engineering, Butterworths Scientific Publications, London, pp. 394–398.
Vargas JE, Oliveira, ARB, Costa Filho, LM & Campos, TP 1986, ‘A study of the relationship between the stability of slopes in residual soils and rain intensity’, Proceedings of the International Symposium on Environmental Geotechnology, Envo Publishing, Leigh, pp. 491–500.
Wen, BP & Aydin, A 2003, ‘Microstructural study of a natural slip zone, quantification and deformation history’, Engineering Geology, vol. 68, pp. 289–317.
Wesley, LD 2010a, Fundamentals of Soil Mechanics for Sedimentary and Residual Soils, John Wiley & Sons Ltd, New York.
Wesley, LD 2011, ’Stability of slopes in residual soils’, Obras y Proyectos, no. 10, pp. 47–61.
Wesley, LD 2013, ‘Residual soils and the teaching of soil mechanics’, in P Delage, J Desrues, R Frank, A Puech & F Schlosser (eds), Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Presses des Pontes, France, pp. 3481–3482.
West, LJ, Hencher, SR, & Cousens, TW 1991, ‘Assessing the stability of slopes in heterogeneous soils’, in DH Bell (ed.), Proceedings of the 6th International Symposiums on Landslides, A.A. Balkema, Rotterdam, pp. 591–595.
Wilkinson, PL, Anderson, MG & Lloyd, DM, 2002, ‘An integrated hydrological model for rain‐induced landslide prediction’, Earth Surface Processes and Landforms: The Journal of the British Geomorphological Research Group, vol. 27, no. 12, pp. 1285–1297.




© Copyright 2024, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
View copyright/legal information
Please direct any queries or error reports to repository-acg@uwa.edu.au