DualSPHysics model has been applied to study the complex phenomenon of wave overtopping characterising dike-promenade coastal defence layout. The model has been first validated, by comparing the results versus laboratory data obtained during a project campaign at the Maritime Engineering Laboratory of Universitat Politècnica de Catalunya – BarcelonaTech (LIM/UPC). The coastal area of Premià de Mar, in Catalonia, has been selected as case study. This stretch of the coast presents both railways and a bike path very close to the shore and therefore exposed to possible sea storms (Figure 1a). Numerical modelling was employed to extend the experimental database beyond the range of tested conditions. Cumulative overtopping volumes are calculated and compared with the experimental ones (Figure 1c), showing a very good agreement and accuracy in terms of overtopping not showing before in previous studies. Despite the initial relatively coarse resolution (=0.01cm), results were accurate. Same accuracy was found for different tests. Upscaling the overtopping discharge to real conditions, it results about 11 l/s/m, beyond the safety limits imposed in literature for design of coastal defences (EurOtop, 2018). Hence, the applicability and impact is focused on reducing discharge under tolerable values. One solution corresponds to hard countermeasures to reduce overtopping discharge, employing a storm wall located on the dike crest. The other one is representative of soft countermeasures, namely beach nourishment, where the beach profile has been changed to shallower conditions (cotθ=30) to provoke more intense wave breaking and dissipate the incoming wave energy (Figure 1b). Both alternatives guarantee tolerable discharges for coastal safety (Figure 1c). Results of the numerical modelling are going to be presented during the 15th International SPHERIC Workshop.

DualSPHysics model has been employed as an aid for a planned experimental campaign that will be carried out at the Maritime Engineering Laboratory of Universitat Politècnica de Catalunya-BarcelonaTech (LIM/UPC). Results of the numerical modelling have been published here.