Influence of surface lining type on the probability of dike breaching due to overtopping

The reliability analysis of a flood protection dike depends on the probability of its failure. In this context, the surface lining covering the landside slope of the dike plays a considerable role, as it protects the dike against failure due to overtopping. A mathematical model describing the overtopping and erosion processes is proposed. The overtopping is simulated using simple surface hydraulics equations while the erosion initiation is linked to the lining resistance. For the modelling of erosion, a simple transport equation was used with erosion parameters. In order to obtain a probabilistic solution, the uncertainty in the involved parameters was taken into account and the Latin Hypercube Sampling method was used. Eight different types of lining material were tested for a chosen dike. Typical phases of the dike breaching due to overtopping were distinguished. The final results take the form of probabilities for those typical phases for each lining material.