Numerical Modeling of Abutment Scour with the Focus on the Incipient Motion on Sloping Beds
Publication: Journal of Hydraulic Engineering
Volume 137, Issue 10
Abstract
A three-dimensional computational fluid dynamics model is applied to predict local scour around an abutment in a rectangular laboratory flume. When modeling local scour, steep bed slopes up to the angle of repose occur. To predict the depth and the shape of the local scour correctly, the reduction of the critical shear stress due to the sloping bed must be taken into account. The focus of this study is to investigate different formulas for the threshold of noncohesive sediment motion on sloping beds. Some formulas only take the transversal angle (perpendicular to the flow direction) into account, but others also consider the longitudinal angle (streamwise direction). The numerical model solves the transient Reynolds-averaged Navier-Stokes equations in all three dimensions to compute the water flow. Sediment continuity in combination with an empirical formula is used to capture the bed load transport and the resulting bed changes. When the sloping bed exceeds the angle of repose, the bed slope is corrected with a sand-slide algorithm. The results from the numerical simulations are compared with data from physical experiments. The reduction of the bed shear stress on the sloping bed improves the results of the numerical simulation distinctly. The best results are obtained with the formulas that use both the transversal and the longitudinal angle for the reduction of the critical bed shear stress.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to thank Dr. Alessio Radice and Professor Francesco Ballio from the Politecnio di Milano for their support and for providing the data used in this paper. The study was funded by the UNSPECIFIEDResearch Council of Norway through the FRINAT program.
References
Apsley, D. D., and Stansby, P. K. (2008). “Bed-load sediment transport on large slopes: Model formulation and implementation within RANS solver.” J. Hydraul. Eng., 134(10), 1440–1451.
Brookes, H. (1963). “Discussion of ‘Boundary shear stress in curved trapezoidal channels’ by A. T. Ippen and P. A. Drinker.” J. Hydraul. Eng., 89(3), 327–333.
Coleman, S. E., Lauchlan, C. S., and Melville, B. W. (2003). “Clear-water scour development at bridge abutments.” J. Hydraul. Res., 41(5), 521–531.
Dey, S. (2001). “Experimental studies on incipient motion of sediment particles on generalized sloping fluvial beds.” Int. J. Sediment Res., 16, 391–398.
Dey, S. (2003). “Threshold of sediment motion on combined transverse and longitudinal sloping beds.” J. Hydraul. Res., 41(4), 405–415.
Escauriaza, C., and Sotiropoulos, F. (2009). “The dynamics of bed-forms around scour holes.” 33rd IAHR Congress: Water engineering for a sustainable environment, International Association for Hydraulic Research, Madrid, Spain.
Ikeda, S. (1982). “Incipient motion of sand particles on side slopes.” J. Hydraul. Div., 108(1), 95–114.
Kirkil, G., Constantinescu, S. G., and Ettema, R. (2008). “Coherent structures in the flow field around a circular cylinder with scour hole.” J. Hydraul. Eng., 134(5), 572–587.
Kovacs, A., and Parker, G. (1994). “A new vectorial bedload formulation and its application to the time evolution of straight river channels.” J. Fluid Mech., 267, 153–183.
Lane, E. W. (1955). “Design of stable channels.” Trans. Am. Soc. Civ. Eng., 120, 1234–1260.
Launder, B. E., and Spalding, D. B. (1974). “The numerical computation of turbulent flows.” Comput. Methods Appl. Mech. Eng., 3(3), 269–289.
Laursen, E. M. (1963). “An analysis of relief bridge scour.” J. Hydraul. Div., 89(3), 93–118.
Lysne, D. K. (1969). “Movement of sand in tunnels.” J. Hydraul. Div., 95(6), 1835–1846.
Melville, B. W. (1992). “Local scour at bridge abutments.” J. Hydraul. Eng., 118(4), 615–631.
Nagata, N., Hosoda, T., Nakato, T., and Yoshio Muramoto, Y. (2005). “Three-dimensional numerical model for flow and bed deformation around river hydraulic structures.” J. Hydraul. Eng., 131(12), 1074–1087.
Olsen, N. R. B. (2007). A three-dimensional numerical model for simulation of sediment movements in water intakes with multiblock option, users manual, Norwegian Univ. of Science and Technology, Trondheim, Norway.
Olsen, N. R. B., and Kjellesvig, H. M. (1998). “Three-dimensional numerical flow modelling for estimation of maximum local scour depth.” J. Hydraul. Res., 36(4), 579–590.
Olsen, N. R. B., and Melaaen, M. C. (1993). “Three-dimensional calculation of scour around cylinders.” J. Hydraul. Eng., 119(9), 1048–1054.
Patankar, S. V., and Spalding, D. B. (1972). “A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows.” Int. J. Heat Mass Transfer, 15(15), 1787–1806.
Radice, A., Ballio, F., Armenio, V., and Franzetti, S. (2006). “Scour development and sediment motion at rectangular and trapezoidal abutments.” Proc., 3rd Int. Conf. on Scour and Erosion, International Society for Soil Mechanics and Geotechnical Engineering, London.
Rhie, C., and Chow, W. (1983). “Numerical study of the turbulent flow past an airfoil with trailing edge separation.” AIAA J., 21(11), 1525–1532.
Rijn, L. C. v. (1984a). “Sediment transport, Part I: Bed load transport.” J. Hydraul. Eng., 110(10), 1431–1457.
Rijn, L. C. v. (1984b). “Sediment transport, Part II: Suspended load transport.” J. Hydraul. Eng., 110(11), 1613–1641.
Roulund, A., Sumer, B. M., Fredsøe, J., and Michelsen, J. (2005). “Numerical and experimental investigation of flow and scour around a circular pier.” J. Fluid Mech., 534, 351–401.
Seminara, G., Solari, L., and Parker, G. (2002). “Bed load at low Shields stress on arbitrarily sloping beds: Failure of the Bagnold hypothesis.” Water Resour. Res., 38, 1–16.
Sturm, T. (2006). “Scour around bankline and setback abutments in compound channels.” J. Hydraul. Eng., 132(1), 21–32.
Information & Authors
Information
Published In
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Dec 18, 2008
Accepted: Feb 4, 2011
Published online: Feb 8, 2011
Published in print: Oct 1, 2011
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.