BOUSSINESQ MODELLING OF DIKE BREACHING DUE TO OVERTOPPING

In the present work a Boussinesq type model is adopted to simulate the breaching and erosion of a sand dike by overtopping. The existing (breaking and non-breaking) wave propagation and bed morphology evolution model is adopted to simulated wave and flow overtopping, by introducing appropriated simple boundary conditions both on the upstream and downstream dike slope). By incorporating sediment transport formulae (for both bed load and suspended load) the model can be applied to simulate bed morphology evolution and erosion process. 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. Model results are compared with experimental data of Van Emelen et al (2013).