Boussinesq modelling of sand dike breaching due to overtopping

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Panayotis Prinos, Theophanis Karambas

Tuesday 30 june 2015

11:15 - 11:30h at Mississippi (level 1)

Themes: (T) Sediment management and morphodynamics, (ST) Sediment transport mechanisms and modelling

Parallel session: 5A. Sediment - Erosion

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In the present work a Boussinesq type model is adopted to simulate the overtopping flow and the sand dike breaching. The existing (breaking and non-breaking) wave propagation and bed morphology evolution model (Karambas and Koutitas, 2002, Karambas, 2012) is adopted to simulate flow overtopping by introducing appropriated very simple boundary conditions both on the upstream and downstream dikeslope, according to Cho and Kim (2009). By incorporating sediment transport formulae (both for bed load and suspended load) the model can be applied to simulate bedmorphology evolution. The paper focuses on the hydraulics of water flowing over a dike (subcritical flow from the reservoir to the dike crest, transcritical flow on the crest, supercritical flow on the downstream dike, hydraulic jump formation), as well as on the erosion process (Figure 1). Model results are compared satisfactorily with experimental data of Van Emelen et al (2013). Figure 1. Dike profile evolution REFERENCES Cho Y-S, J-K Kim (2009). Moving boundary treatment in run-up process of tsunami. Journal of Coastal Research, SI 56, ICS2009 Proceedings, pp. 482-486. Karambas Th. V. and C. Koutitas. 2002. Surf and swash zone morphology evolution induced by nonlinear waves, Journal of Waterway, Port, Coastal and Ocean Engineering, American Society of Civil Engineers (ASCE), Vol. 128, no 3, pp. 102-113. Karambas Th. V. (2012) ‘Design of detached breakwaters for coastal protection: development and application of an advanced numerical model’ Proceedings of the 33rd International Conference on Coastal Engineering 2012,1(33), sediment.115. doi:10.9753/icce.v33.sediment.115 Van Emelen, S., Ferbus, V., Spitaels, T., Zech, Y., and Soares-Frazão, S. (2013) 'Experimental investigation of the erosion of a sand dike by overtopping' Proc. 35th IAHR World Congress, Chengdu, China.