A hybrid physical and numerical methodology to analyze scouring processes on sharp nose complex piers due to fluvial flooding events. Lužný Bridge over the Danube River, Bratislava
During the design of the new Danube Bridge (‘Lužný most’) in Bratislava, Slovakia, the scouring processes on a movable bed were assessed using a hybrid physical and numerical methodology and applied to sharp-nosed complex piers. The objectives included analyzing changes in riverbed topography, calculating the scour depth and affected area, assessing the stability of scour countermeasures, and gaining a better understanding of the spatial distribution of fluvial circulation around the bridge piers. The study began with the theoretical scour depth values calculated with the HEC-18 methodology. Due to its limitations, a physical model was built to test the storm events of Q20 and Q100 return periods using real data, for different geometries of the piers. Physical test results validated the hydro-morphodynamical modelling of sharp nose piers using Delft3D. A correlation and a more accurate approach for assessing scouring for simple and complex sharp-nose piers was made after comparing the hybrid methodology with HEC-18 formulation.