NUMERICAL-EXPERIMENTAL MODELLING OF LOCAL SCOURING DOWNSTREAM OF PROTECTED BRIDGES IN ALLUVIAL RIVER BEDS

Autores UPV
Año
CONGRESO NUMERICAL-EXPERIMENTAL MODELLING OF LOCAL SCOURING DOWNSTREAM OF PROTECTED BRIDGES IN ALLUVIAL RIVER BEDS

Abstract

Bridges with a protected river bed under the structure suffer a combination of different types of erosion during flood events. Local scour develops upstream piles and abutments. Contraction scour is present due to the narrowing of the cross section. And finally, erosion downstream the protected zone may occur as a result of a change in the riverbed rigidity. These phenomena cannot be separately studied, as their total effect does not equal a simple addition of the single effects. In this paper, an experimental campaign is conducted in order to evaluate how the factors involved in this phenomenon affect total scour and its dimensions. Furthermore, one of the experiments is simulated by means of a hydraulic mathematical model, which incorporates sediment transport equations. Agreement between numerical and experimental results is discussed, alongside the proposal of future model improvements.