Abstract
Obtaining representative samples for laboratory shear strength testing forms the foundation of a successful geotechnical investigation program. The selection of suitable laboratory testing methods and the understanding of their limitations in the mining of a mineral sands deposit is discussed. The pit slopes will comprise of cohesionless sand and silty sand. The method of recovering undisturbed samples in a deep drilling program is outlined. The use of undisturbed samples increases confidence and reliability in probabilistic stability analysis. The effective friction angle values from 40 consolidated undrained triaxial and 46 direct shear tests are compared. The direct shear test results are 5% lower than the triaxial test results due to subhorizontal bedding. In addition, the coefficient of variation for the triaxial and direct shear friction angle results are 4.3% and 9% respectively, indicating a larger dispersion in the direct shear test results. The triaxial and direct shear datasets result in distinctly different outcomes for pit slope optimisation studies with substantial financial implications. Incorporating triaxial test data in a 35° pit slope stability assessment results in a 36% higher confidence level of achieving or exceeding a factor of safety of 1.3, relative to using the direct shear test data.
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References
AS1289.6.2.2-1998 (1998) Methods of testing soils for engineering purposes. AS1289.6.2.2-1998, Standards Australia
AS1289.6.4.2-1998 (1998) Methods of testing soils for engineering purposes. AS1289.6.4.2-1998, Standards Australia
AS1726-1993 (1993) Geotechnical site investigations. AS1726-1993, Standards Australia
Bilgin O, Arens K, Dettloff A (2019) Assessment of variability in soil properties from various field and laboratory tests. Georisk 13(4):247–254, DOI: https://doi.org/10.1080/17499518.2019.1645338
Bolton MD (1986) The strength and dilatancy of sands. Géotechnique 36(1):65–78, DOI: https://doi.org/10.1680/geot.1986.36.1.65
Bowles JE (1996) Foundation analysis and design, 5th edition. McGraw-Hill Companies, Inc., Singapore, 162–163
Brandon TL (2013) Advances in shear strength measurement, assessment, and use for slope stability analysis. Geo-Congress 2013, March 3–7, San Diego, CA, USA, DOI: https://doi.org/10.1061/9780784412787.226
Briaud J (2013) Geotechnical engineering: Unsaturated and saturated soils. John Wiley & Sons, Inc., Hoboken, NJ, USA, 54–56+198–199
Brown CM (1985) Murray basin, southeastern Australia: Stratigraphy and resource potential — A synopsis. Bureau of Mineral Resources, Geology and Geophysics, Australian Government Publishing Service, Canberra, Australia, 1–24
Cao Z, Wang Y, Au S (2011) CPT-based probabilistic characterization of effective friction angle of sand. Georisk 2011, June 26–28, Atlanta, GA, USA, DOI: https://doi.org/10.1061/41183(418)36
Castellanos BA, Brandon TL (2013) A comparison between the shear strength measured with direct shear and triaxial devices on undisturbed and remolded soils. Proceedings of the 18th international conference on soil mechanics and geotechnical engineering, Paris, France
Chen A, Zhang J (2019) Strength and deformation characteristics of silty sand improved by gravel. KSCE Journal of Civil Engineering 23(2):525–533, DOI: https://doi.org/10.1007/s12205-018-1047-x
Christian JT, Baecher GB (2011) Unresolved problems in geotechnical risk and reliability. Georisk 2011, June 26–28, Atlanta, GA, USA, DOI: https://doi.org/10.1061/41183(418)3
Das BM (2008) Advanced soil mechanics, 3rd edition. Taylor & Francis, New York, NY, USA, 373–401
Dayal N, Prieto AR, Lewis JP, Scherer RD (2011) Probabilistic slope stability analysis as a supplement to a deterministic study. Georisk 2011, June 26–28, Atlanta, GA, USA, DOI: https://doi.org/10.1061/41183(418)16
DEH (2000) Coorong, and lakesalexandrina and albert ramsar management plan. Department of Environment and Heritage (DEH), Adelaide, Australia
Dodge Y (2008) The concise encyclopedia of statistics. Springer, New York, NY, USA, 95–267
Duncan JM (2000) Factors of safety and reliability in geotechnical engineering. Journal of Geotechnical and Geoenvironmental Engineering 126(4):307–316, DOI: https://doi.org/10.1061/(ASCE)1090-0241(2000)126:4(307)
Duncan JM, Sleep M (2017) The need for judgement in geotechnical reliability studies. Georisk 11(1):70–74, DOI: https://doi.org/10.1080/17499518.2016.1214870
Garga VK, Zhang H (1997) Volume changes in undrained triaxial tests on sands. Canadian Geotechnical Journal 34(5):762–772, DOI: https://doi.org/10.1139/t97-038
Gitirana Jr GFN, Fredlund DG (2016) Statistical assessment of hydraulic properties of unsaturated soils. Soils and Rocks 39(1):81–95, DOI: https://doi.org/10.28927/SR.391081
Greco VR (2016) Variability and correlation of strength parameters inferred from direct shear tests. Geotechnical and Geological Engineering 34(2):585–603, DOI: https://doi.org/10.1007/s10706-015-9968-3
Hanna A, Ayadat T (2019) Comparative study of shear strength characteristics of dry cohesionless sands from triaxial, plane-strain and direct shear tests. Geomechanics and Geoengineering 16:150–162, DOI: https://doi.org/10.1080/17486025.2019.1648882
Hofmann BA, Sego DC, Robertson PK (2000) In situ ground freezing to obtain undisturbed samples of loose sand. Journal of Geotechnical and Geoenvironmental Engineering 126(11):979–989, DOI: https://doi.org/10.1061/(ASCE)1090-0241(2000)126:11(979)
Etøeg K, Dyvik R, Sandbækken G (2000) Strength of undisturbed versus reconstituted silt and silty sand specimens. Journal of Geotechnical and Geoenvironmental Engineering 126(7):606–617, DOI: https://doi.org/10.1061/(ASCE)1090-0241(2000)126:7(606)
Jaksa MB, Goldsworthy JS, Fenton GA, Kaggwa WS, Griffiths DV, Kuo YL, Poulos HG (2005) Towards reliable and effective site investigations. Géotechnique 55(2):47–59, DOI: https://doi.org/10.1680/geot.2005.55.2.109
Kim Y (2009) Static simple shear characteristics of Nak-dong River clean sand. KSCE Journal of Civil Engineering 13(6):389–401, DOI: https://doi.org/10.1007/s12205-009-0389-9
Lacasse S, Nadim F (1996) Uncertainties in characterizing soil properties. Uncertainty in the Geologic Environment: From Theory to Practice 1:49–75
Low BK (2007) Reliability analysis of rock slopes involving correlated nonnormals. International Journal of Rock Mechanics & Mining Sciences 44(6):922–935, DOI: https://doi.org/10.1016/j.ijrmms.2007.02.008
Maranha JR, Maranha das Neves E (2009) The experimental determination of the angle of dilatancy in soils. Proceedings of the 17th international conference on soil mechanics and geotechnical engineering, October 5–9, Alexandria, Egypt
Marcuson III WF, Franklin AG (1979) State of the art of undisturbed sampling of cohesionless soils. Miscellaneous Paper GL-79–16, U. S. Army Chief of Engineers, Washington DC, USA
McGuire MP, VandenBerge DR (2017) Interpretation of shear strength uncertainty and reliability analyses of slopes. Landslides 14:2059–2072, DOI: https://doi.org/10.1007/s10346-017-0836-5
Medzvieckas J, Dirgėlienė N, Skuodis (2017) Stress-strain states differences in specimens during triaxial compression and direct shear tests. Procedia Engineering 172:739–745, DOI: https://doi.org/10.1016/j.proeng.2017.02.094
Miranda JA, Wallace MW, McLaren S (2009) Tectonism and eustasy across a Late Miocene strandplain: The Loxton—Parilla Sands, Murray basin, southeastern Australia. Sedimentary Geology 219(1–4):24–43, DOI: https://doi.org/10.1016/j.sedgeo.2009.03.012
Moayed RZ, Alibolandi M, Alizadeh A (2017) Specimen size effects on direct shear test of silty sands. International Journal of Geotechnical Engineering 11(2):198–205, DOI: https://doi.org/10.1080/19386362.2016.1205166
Moffat R, Rivera D (2013) Back-analysis & in-situ shear testing studies to estimate shear strength parameters on an actual slope. Geo-Congress 2013, March 3–7, San Diego, CA, USA, DOI: https://doi.org/10.1061/9780784412787.017
Mollahasani A, Alavi AH, Gandomi AH, Rashed A (2011) Nonlinear neural-based modeling of soil cohesion intercept. KSCE Journal of Civil Engineering 15(5):831–840, DOI: https://doi.org/10.1007/s12205-011-1154-4
Nishimura S, Murakami A, Matsuura K (2010) Reliability-based design of earth-fill dams based on the spatial distribution of strength parameters. Georisk 4(3):140–147, DOI: https://doi.org/10.1080/17499511003676655
Phoon K (2017) Role of reliability calculations in geotechnical design. Georisk 11(1):4–21, DOI: https://doi.org/10.1080/17499518.2016.1265653
Phoon K (2020) The story of statistics in geotechnical engineering. Georisk 14(1):3–25, DOI: https://doi.org/10.1080/17499518.2019.1700423
Phoon K, Kulhawy FH (1999) Characterization of geotechnical variability. Canadian Geotechnical Journal 36(4):612–624, DOI: https://doi.org/10.1139/t99-038
Razeghi HR, Romiani HM (2015) Experimental investigation on the inherent and initial induced anisotropy of sand. KSCE Journal of Civil Engineering 19(3):583–591, DOI: https://doi.org/10.1007/s12205-012-0373-7
Rowe PW (1969) The relation between the shear strength of sands in triaxial compression, plane strain and direct shear. Géotechnique 19(1):75–86
Schneider HR, Schneider MA (2013) Dealing with uncertainties in EC7 with emphasis on determination of characteristic soil properties. In: Arnold P, Fenton GA, Hicks MA, Schweckendiek T, Simpson B (eds) Modern geotechnical design codes of practice, implementation, application and development. IOS Press, Amsterdam, Netherlands, 87–101
Schultze E (1971) Frequency distributions and correlations of soil properties. Proceedings of the 1st international conference on applications of statistics and probability to soil and structural engineering, September 13–16, Hong Kong
Sharma MSR, Baxter CDP, Hoffmann W, Moran K, Vaziri H (2011) Characterization of weakly cemented sands using nonlinear failure envelopes. International Journal of Rock Mechanics & Mining Sciences 48(1):146–151, DOI: https://doi.org/10.1016/j.ijrmms.2010.06.008
Shen H, Luo X, Bi J (2018) An alternative method for internal stability prediction of gravelly soil. KSCE Journal of Civil Engineering 22(4):1141–1149, DOI: https://doi.org/10.1007/s12205-017-1570-1
Singh A (1971) How reliable is the factor of safety in foundation engineering. Proceedings of the 1st international conference on applications of statistics and probability to soil and structural engineering, September 13–16, Hong Kong
Uzielli M (2008) Statistical analysis of geotechnical data. Proceedings of the 3rd international conference on site characterization, Taipei, Taiwan
van Staveren MT (2009) Extending to geotechnical risk management. Georisk 3(3):174–183, DOI: https://doi.org/10.1080/17499510902788835
Wesseloo J, Read J (2009) Acceptance criteria. In: Read J, Stacey P (eds) Guidelines for open pit slope design. CSIRO Publishing, Collingwood, Australia, 221–236
Wu XZ (2017) Implementing statistical fitting and reliability analysis for geotechnical engineering problems in reliability engineering and system safety. Georisk 11(2):173–188, DOI: https://doi.org/10.1080/17499518.2016.1201577
Yoshimi Y, Hatanaka M, Oh-oka H (1978) Undisturbed sampling of saturated sands by freezing. Soils and Foundations 18(3):59–73, DOI: https://doi.org/10.3208/sandf1972.18.3_59
Yoshimi Y, Tokimatsu K, Kaneko O, Makihara Y (1984) Undrained cyclic shear strength of a dense Niigata sand. Soils and Foundations 24(4):131–145, DOI: https://doi.org/10.3208/sandf1972.24.4_131
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Sonnekus, M.C.H., Smith, J.V. Comparing Shear Strength Dispersion Characteristics of the Triaxial and Direct Shear Methods for Undisturbed Dense Sand. KSCE J Civ Eng 26, 1560–1568 (2022). https://doi.org/10.1007/s12205-022-0040-6
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DOI: https://doi.org/10.1007/s12205-022-0040-6