Document Type : Research Paper

Authors

Department of Water Engineering, College of Agriculture, Bu-Ali Sina University, Hamadan, Iran.

Abstract

This paper presents a comprehensive experimental and numerical study using non-cohesive uniform sand (d50 = 2 mm). The study investigates the impact of local scour downstream of four model culverts with different barrel shapes and inlet blockage sizes. The results show that, for clear water scour, the shape and number of culvert barrels affect downstream scour geometry. The most affected parameters of scour hole geometry in blocked inlet culverts were the maximum scour depth near the walls (dswall) and the maximum scoured sediment volume (ζs). The dswall ⁄ D values of rectangular model culverts were 1.3 to 1.5 times greater than those of circular model culverts. The results showed that the effect of inlet obstruction on dsmax is contingent on flow and culvert conditions. Based on this, a suitable relationship was proposed to estimate the maximum scour depth for each cross-section. The presented equations were compared to the existing equation based on inlet blockage by applying collected datasets and they showed superior performance. The comparison indicated that over 80% of the predicted values fall within ±30% error lines.

Keywords

Abida, H. and Townsend, R. D. (1991) ‘Local scour downstream of box-culvert outlets’, Journal of Irrigation and Drainage Engineering, 117(3), pp. 425-440. doi: https://doi.org/10.1061/(ASCE)0733-9437(1991)117:3(425)
Allen, D. et al., (2015) ‘Provision, transport and deposition of debris in urban waterways’, International Journal of Sediment Research, 30(2), pp.142-149. doi: https://doi.org/10.1016/j.ijsrc.2015.03.006
Armitage, N. P. and Rooseboom, A. (1999) ‘The removal of litter from storm water conduits in the developing world’, Water Science and Technology, 39(9), pp. 277-284. doi: https://doi.org/10.1016/S0273-1223(99)00242-5
Bodhaine, G. L. (1968) Measurement of peak discharge at culverts by indirect methods. 1st edn. US Government Printing Office, Washington, DC.
Day, R. A., Liriano, S. L. and White, W. R. (2001) ‘Effect of tailwater depth and model scale on scour at culvert outlets’, Proceedings of the Institution of Civil Engineers-Water and Maritime Engineering, 148, (3), pp. 189-198. doi: https://doi.org/10.1680/wame.2001.148.3.189
Galan, A. and Gonzalez, J. (2020) ‘Effects of shape, inlet blockage and wing walls on local scour at the outlet of non-submerged culverts: undermining of the embankment’, Environmental Earth Science., 79(1), pp. 25-37. doi: https://doi.org/10.1007/s12665-019-8749-3
Ho, H. C., Muste, M. and Ettema, R. (2013) ‘Sediment self-cleaning multi-box culverts’, Journal of Hydraulic Research, 51(1), pp. 92-101. doi: https://doi.org/10.1080/00221686.2012.757565
Hotchkiss, R. H., Larson, E. A. and Admiraal, D. M. (2005) ‘Energy dissipation in culverts by forced hydraulic jump within a barrel’, Journal of transportation Research Board, 1904(1), pp. 124-132. doi: https://doi.org/10.1177/0361198105190400113
Liriano, S. L., Day, R. A. and White, W. R. (2002) ‘Scour at culvert outlets as influenced by the turbulent flow structure’ Journal of Hydraulic Research, 40(3), pp. 367-376. doi: https://doi.org/10.1080/00221680209499951
Melville, B. W. and Lim, S. Y. (2013) ‘Scour caused by 2D horizontal jets’, Journal of Hydraulic Engineering, 140(2), pp. 149-155. doi: https://doi.org/10.1061/(ASCE)HY.1943-7900.0000807
Pagliara, S. and Carnacina, I. (2011) ‘Influence of large woody debris on sediment scour at bridge piers’, International Journal of Sediment Research, 26(2), pp. 121-136. doi: https://doi.org/10.1016/S1001-6279(11)60081-4
Sarathi, P., Faruque, M. A. A. and Balachandar, R. (2008) ‘Influence of tailwater depth, sediment size and densimetric Froude number on scour by submerged square wall jets’, Journal of Hydraulic Research, 46(2), pp. 158-175. doi: https://doi.org/10.1080/00221686.2008.9521853
Smith, G. L., (1957) Scour and energy dissipation below culvert outlets. 1st edn. Colorado Agricultural and Mechanical College, Department of Civil Engineering, Colorado.
Sorourian, S., Keshavarzi, A. and Ball, J. E. (2015) ‘Scour at partially blocked box-culverts under steady flow’, Proceedings of the Institution of Civil Engineers-Water Management, 169 (6), pp. 247-259. doi: https://doi.org/10.1680/jwama.15.00019
Streftaris, G. et al. (2012) Modeling probability of blockage at culvert trash screens using Bayesian approach’, Journal of Hydraulic Engineering, 139 (7), pp. 716-726. doi: https://doi.org/10.1061/(ASCE)HY.1943-7900.0000723
Taha N. et al. (2020) ‘Numerical investigation of scour characteristics downstream of blocked culverts’, Alexandria Engineering Journal, 59 (5), pp. 3503-3513. doi: https://doi.org/10.1016/j.aej.2020.05.032
Wallerstein, N. and Arthur, S. (2012) ‘Improved methods for predicting trash delivery to culverts protected by trash screens’, Journal of Flood Risk Management, 5(1), pp. 23-36. doi: https://doi.org/10.1111/j.1753-318X.2011.01122.x
Wang, H., Uys, W. and Chanson, H. (2018) ‘Alternative mitigation measures for fish passage in standard box culverts: physical modelling’, Journal of Hydro-Environment Research, 19, pp. 214-223. doi: https://doi.org/10.1016/j.jher.2017.03.001
Zhang, R. and Wu, P. (2019) ‘The investigation of shape factors in determining scour depth at culvert outlets. ISH Journal of Hydraulic Engineering, pp. 1-7. doi: https://doi.org/10.1080/09715010.2019.1611492
Zhao, P., Yu, G. and Zhang, M. (2019) ‘Local scour on noncohesive beds by a submerged horizontal circular wall jet’, Journal of Hydraulic Engineering, 145(9), pp. 190-196. doi: https://doi.org/10.1061/(ASCE)HY.1943-7900.0001623