Laboratory Study of the Hydraulics of Flow in Gabion Stepped Weirs

Document Type : Research Article


1 PhD candidate, University of Tabriz, Tabriz-Iran

2 Professor, Water engineering department, University of Tabriz, Tabriz-Iran


In this study, different components that affect energy dissipation on flow over gabion-stepped spillways were investigated using physical models, and comparisons were made with the other studies. Flow over gabion spillway was conducted in both through flow and overflow simultaneously. The discharge is in the range of 5 to 65 liters per second.  Uniform particles with three medium diameters of 10, 25, and 40 mm were used. The height and width of the physical models were 60 and 40 cm, respectively, with 3 steps and the downstream slope of weirs was 1:1, 1:2, and 1:3 (V: H). Tow end sills including rectangular and inclined shapes were used. The results showed that the effect of end sills in gabion-stepped weirs with lower slope is more than that of weirs comprising higher slope. The effect of the end sills on the energy dissipation in the weir for d50=40 mm and S=1:2 is about 10% more than the weir with d50=10 mm and S=1:1. In weir including d50=10 mm and S=1:2 is about 30 to 35 percent more than the weir with d50=10 mm and S=1:1. Therefore, the existence of end sills in the weirs with the body of materials of d50=10 and 40 mm have the highest and the least effects on the energy dissipation. On the other hand, the effect of the rectangular end sill on the energy loss is about 3-4% more than that the effect of the triangular end sill.


Main Subjects

[1] Ohtsu, Y. Yasuda, M. Takahashi, Flow characteristics of skimming flows in stepped channels, Journal of Hydraulic Engineering, 130(9) (2004) 860-869.
[2] C. Chinnarasri, S. Donjadee, U. Israngkura, Hydraulic characteristics of gabion-stepped weirs, Journal of Hydraulic Engineering, 134(8) (2008) 1147-1152.
[3] F. Salmasi, M. Chamani, D.F. Zadeh, Experimental study of energy dissipation over stepped gabion spillways with low heights, Iranian Journal of Science and Technology. Transactions of Civil Engineering, 36(C2) (2012) 253.
[4] H.I. Mohamed, Flow over gabion weirs, Journal of Irrigation and Drainage Engineering, 136(8) (2009) 573-577.
[5] R.M. Sorensen, Stepped spillway hydraulic model investigation, Journal of Hydraulic Engineering, 111(12) (1985) 1461-1472.
[6] W. Rand, Flow geometry at straight drop spillways, in:  Proceedings of the American Society of Civil Engineers, ASCE, 1955, pp. 1-13.
[7] L.A. Peyras, P. Royet, G. Degoutte, Flow and energy dissipation over stepped gabion weirs, Journal of Hydraulic Engineering, 118(5) (1992) 707-717.
[8] G.C. Christodoulou, Energy dissipation on stepped spillways, Journal of Hydraulic Engineering, 119(5) (1993) 644-650.
[9] M. Chamani, N. Rajaratnam, Characteristics of skimming flow over stepped spillways, Journal of Hydraulic Engineering, 125(4) (1999) 361-368.
[10] U. Fratino, A. Piccinni, G. de Marinis, Dissipation efficiency of stepped spillways, in:  H.-E. Minor and W. Hager, Proceeding of the International Workshop on Hydraulics of Stepped Spillways, IAHR, AA Balkema/Rottersam/Brookfield, Zurich, Switzerland, 2000.
[11] T. Chaturabul, Experimental study of flow behavior through stepped channels with end sills, MS Thesis, King Mongkut’s University of Technology, Thailand, 2002.
[12] C. Chinnarasri, S. Wongwises, Flow Patterns and Energy Dissipation over Various Stepped Chutes, Journal of Irrigation and Drainage Engineering, 132(1) (2006) 70-76.
[13] A. Hamedi, A. Mansoori, I. Malekmohamadi, H. Roshanaei, Estimating energy dissipation in stepped spillways with reverse inclined steps and end sill, in:  World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability, 2011, 2528-2537.
[14] M. Tuna, Effect of offtake channel base angle of stepped spillway on scour hole, Iranian Journal of Science and Technology. Transactions of Civil Engineering, 36(C2) (2012) 239.
[15] M.C. Tuna, M.E. Emiroglu, Effect of step geometry on local scour downstream of stepped chutes, Arabian Journal for Science and Engineering, 38(3) (2013) 579-588.
[16] H.K. Zare, J.C. Doering, Effect of rounding edges of stepped spillways on the flow characteristics, Canadian Journal of Civil Engineering, 39(2) (2012) 140-153.
[17] S. Felder, H. Chanson, Effects of Step Pool Porosity upon Flow Aeration and Energy Dissipation on Pooled Stepped Spillways, Journal of Hydraulic Engineering, 140(4) (2014) 04014002.
[18] D. Wuthrich, H. Chanson, Aeration performances of a gabion stepped weir with and without capping, Environmental Fluid Mechanics, 15(4) (2014) 711-730.
[19] G. Zhang, H. Chanson, Gabion stepped spillway: interactions between free-surface, cavity, and seepage flows, Journal of Hydraulic Engineering, 142(5) (2016) 06016002.
[20] E. Asadi, A.H. Dalir, D. Farsadizadeh, Y. Hassanzaheh, F. Salmasi, Energy dissipation of skimming flow with different sill dimensions in stepped spillway model, International Journal of Agriculture and Biosciences, 4(3) (2015) 118-121.
[21] E.A. Elnikhely, Investigation and analysis of scour downstream of a spillway, Ain Shams Engineering Journal,  9(4) (2018) 2275-2282.
[22] G.M.A. Aal, M. Sobeah, E. Helal, M. El-Fooly, Improving energy dissipation on stepped spillways using breakers, Ain Shams Engineering Journal,  (2017).
[23] S.H. Rajaei, S.R. Khodashenas, K. Esmaili, Laboratory Analysis of Energy Losses in Gabion Steeped Spillways With and Without Sedimentation at Upstream, Iranian Journal of Irrigation and Drainage, 11(5) (2017) 900-910 (In Persian).
[24] M. Sadrianzadeh, M. Mahmoudian, A. Fathi, H. Eslami, Investigation of the Concentration of Mixed Air With the Flow of Water at Different Points on the Stepped Spillway in the Flow Non-falling With the FLUENT Model and a Physical Model, Journal of Water Engineering, 4(2) (2016) 50-58 (In Persian).
[25] C. Chinnarasri, S. Wongwises, Flow regimes and energy loss on chutes with upward inclined steps, Canadian Journal of Civil Engineering, 31(5) (2004) 870-879.
[26] D. Stephenson, Gabion energy dissipators, in:  Proc. 13th ICOLD Congress, 1979, pp. 33-43.
[27] C.l. Chen, Momentum and energy coefficients based on power-law velocity profile, Journal of Hydraulic Engineering, 118(11) (1992) 1571-1584.
[28] H. Chanson, Hydraulics of skimming flows over stepped channels and spillways, Journal of Hydraulic Research, 32(3) (1994) 445-460.
[29] N. Rajaratnam, Skimming flow in stepped spillways, Journal of Hydraulic Engineering, 116(4) (1990) 587-591.
[30] C. Chinnarasri, Assessing the flow resistance of skimming flow on the step faces of stepped spillways, Dam Engineering, 12(4) (2002) 303-322.
[31] I.T.S. Essery, M.W. Horner, The hydraulic design of stepped spillways, Construction Industry Research and Information Association, 1971.
[32] E. Beitz, M. Lawless, Hydraulic model study for dam on GHFL 3791 Isaac River at Burton Gorge, Water Resources Commission Report,  (1992).
[33] J.C. Bathurst, Flow resistance of large-scale roughness, Journal of Hydraulics Division, 104(12) (1978) 1587-1603.
[34] J.C. Bathurst, D.B. Simons, R.-M. Li, Resistance equation for large-scale roughness, Journal of Hydraulics Division, 107(12) (1981) 1593-1613.
[35] S. Pagliara, P. Chiavaccini, Energy dissipation on block ramps, Journal of Hydraulic Engineering, 132(1) (2006) 41-48.