Rock Mass Erodibility
Publication: Journal of Hydraulic Engineering
Volume 143, Issue 5
Abstract
Erosion of rock masses by water typically involves unraveling of blocks of rock along existing defects in a manner that is not represented by analytical solutions for sediment transport or rockfill (rip-rap). A pragmatic approach to this complex problem is found by using a rock mass index to represent the erodibility of the rock-mass. The likelihood of erosion is then assessed by comparison against case studies in similar rock masses. A new independent data set of rock-mass erosion was gained from inspection of 26 unlined spillways in Australia, South Africa, and the United States. It was found that erosion can be usefully correlated against various published rock mass indices and hydraulic indices. A modified rock mass index, developed specifically to represent erodibility, is presented, and is applied to prepare a new comparative erosion assessment method for rock masses.
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References
Annandale, G. W. (1995). “Erodibility.” J. Hydraul. Res., 33(4), 471–494.
Annandale, G. W. (2005). Scour technology: Mechanics and engineering practice, 1st Ed., McGraw-Hill Professional, New York.
Barton, N., Lien, R., and Lunde, J. (1974). “Engineering classification of rock masses for the design of tunnel support.” Rock Mech., 6(4), 189–236.
Bertuzzi, R., Douglas, K., and Mostyn, G. (2016). “Comparison of quantified and chart GSI for four rock masses.” Eng. Geol., 202, 24–35.
Bieniawski, Z. T. (1973). “Engineering classification of jointed rock masses.” Civ. Eng. South Afr., 15(12), 335–344.
Deere, D. U. (1962). Technical description of rock cores for engineering purposes, Univ. of Illinois, Champaign, IL.
Dooge, N. (1993). “Die hidrouliese erodeerbaarheid van rotmassas in onbelynde oorlope met spesiale verwysing na die rol van naatvulmateriaal.” M.Sc. thesis, Univ. of Pretoria, South Africa (in Afrikaans).
Henderson, F. (1966). Open channel flow, 1st Ed., Prentice Hall, Upper Saddle River, NJ.
Hoek, E. (2006). “Practical rock engineering.” ⟨https://www.rocscience.com/hoek/corner/Practical_rock_engineering.pdf⟩ (Jun. 4, 2015).
Hoek, E., and Brown, E. T. (1980). Underground excavations in rock, Institution of Mining and Metallurgy, London.
Hoek, E., Kaiser, P. K., and Bawden, W. F. (1995). Support of underground excavations in hard rock, A.A. Balkema, Rotterdam, Netherlands.
Hudson, J. A., and Harrison, J. P. (2005). Engineering rock mechanics: An introduction to the principles, Pergamon, Tarrytown, NY.
Kirsten, H. (1982). “Classification system for excavation in natural materials.” Civ. Eng. South Afr., 24(7), 293–308.
Kirsten, H. (1995). “Erodibility criterion for jet cutting of intact materials.”, Steffen, Robertson, and Kirsten Incorporated, Johannesburg, South Africa.
Kirsten, H., and Kirsten, L. (1995). “Stream power as a measure of excitation causing hydraulic erosion.”, Stefan, Robertson, and Kirsten Incorporated, Johannesburg, South Africa.
Kirsten, H. A., Moore, J. S., Kirsten, L. H., and Temple, D. M. (2000). “Erodibility criterion for auxiliary spillways of dams.” Int. J. Sediment Res., 15(1), 93–107.
MacGregor, F., Fell, R., Mostyn, G. R., Hocking, G., and McNally, G. (1994). “The estimation of rock rippability.” Q. J. Eng. Geol. Hydrogeol., 27(2), 123–144.
Marinos, P. and Hoek, E. (2000). “GSI—A geologically friendly tool for rock mass strength estimation.” ISRM Int. Symp., International Society for Rock Mechanics, Melbourne, VIC, Australia.
Marinos, P., and Hoek, E. (2001). “Estimating the geotechnical properties of heterogeneous rock masses such as flysch.” Bull. Eng. Geol. Environ., 60(2), 85–92.
Moore, J. (1991). The characterization of rock for hydraulic erodibility, Water Resources Publications, Littleton, CO.
Moore, J., and Kirsten, H. (1988). Discussion—Critique of the rock material classification procedure, L. Kirkaldie, ed. ASTM, West Conshohocken, PA.
Moore, J. S., Temple, D. M., and Kirsten, H. (1994). “Headcut advance threshold in earth spillways.” Bull. Assoc. Eng. Geol., 31(2), 277–280.
Pells, P. J. N. (2008). “What happened to the mechanics in rock mechanics and the geology in engineering geology?” South Afr. Inst. Min. Metall., 108, 309–323.
Pells, S. (2016). “Erosion of rock in spillways.” Ph.D. thesis, UNSW Australia, Kensington, NSW, Australia.
Pells, S., Pells, P., Peirson, W. L., Douglas, K., and Fell, R. (2015a). “Erosion of unlined spillways in rock - does a ‘scour threshold’ exist?” ANCOLD, Brisbane, QLD, Australia.
Pitsiou, S. (1990). “The effect of discontinuities on the erodibility of rock in unlined spillways.” M.Sc. thesis, Univ. of Pretoria, Pretoria, South Africa.
Starfield, A., and Cundall, P. (1988). “Towards a methodology for rock mechanics modelling.” Int. J. Rock Mech. Min. Sci. Geomech. Abstr., 25(3), 99–106.
USACE Hydrologic Engineering Centre. (2010). “HEC-RAS river analysis system hydraulic reference manual.”, Davis, CA.
USSD (United States Society on Dams). (2006). “Erosion of unlined spillways.” Denver.
van Schalkwyk, A. (1994). “Minutes—Erosion of rock in unlined spillways.” ICOLD, Q.71-17, 1056–1062.
van Schalkwyk, A., Jordaan, J., and Dooge, N. (1994a). “Die erodeerbaarheid van verskillende rotsformasies onder varierende vloeitoestande.”, Verslag aan die waternavorsingskommissie deur die Departement of Geologie, Universiteit van Pretoria, South Africa (in Afrikaans).
van Schalkwyk, A., Jordaan, J., and Dooge, N. (1994b). “Erosion of rock in unlined spillways.”, International Commission on Large Dams, Paris.
Information & Authors
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Published In
Journal of Hydraulic Engineering
Volume 143 • Issue 5 • May 2017
Copyright
©2016 American Society of Civil Engineers.
History
Received: Dec 12, 2015
Accepted: Jul 12, 2016
Published online: Nov 29, 2016
Discussion open until: Apr 29, 2017
Published in print: May 1, 2017
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