Hydromorphological Numerical Model of the Local Scour Process Around Bridge Piers

Abstract

The aim of this study was to assess the simulation and prediction of scour processes, both hydrodynamically and morphologically, around vertical and inclined piers. A new version of FLOW-3D v. 11.2, including three sediment transport equations, was extensively used for estimating the scour around the pier. The results of the model in terms of water surface, flow velocity, bed shear stress and scour depth were effectively compared with several sets of the experimental and numerical data in the literature. The model provided an accurate estimation of water surface, flow velocity and bed shear stress. However, the results for the vertical velocity upstream of the pier were underestimated. The predictive capabilities of the model were mainly dependent on the pier shape and inclined direction. The downflow, stream-wise velocity, shear stress and local scour depth were significantly reduced at the inclination angle of the circular pier downstream. However, they were nearly equal to those of an inclined perpendicular circular pier. This study strongly demonstrates that a 3D hydromorphological model can be effectively used to predict the scour depth around piers.