Numerical Simulation of Local Scour around Tandem Bridge Piers

Abstract

Local pier scour is one of the main causes of bridges failure. Many studies were conducted to investigate the pier scour experimentally. Most of them studied the scour at a single pier, while the scour around a group of piers is relatively less studied. Recently, the technological development and advancement in computer abilities presented the numerical models as a promising tool in engineering analysis and design. The numerical models have more flexibility than the physical models and less limitations. The predictive capability of the hydro-morphological model for the scour around bridge piers in clear water conditions have been investigated using FLOW-3D 11.2.2 as a simulation tool. The objective of the study is to investigate the effect of piers interaction at tandem piers arrangement on the resulting scour pattern. The Van Rijn sediment transport model and (RNG) k-ε turbulence model were used to simulate the scour process and sediment transport. The computations of the numerical model have been compared with experimental data from the literature. This study demonstrates that a 3D numerical model can effectively predict the scour around tandem piers, though the scour depth at the nose of the piers was underestimated. It is found that the capability of the numerical model to predict the scour depth at the tandem piers is accepted but it was not effective at estimating the accurate location of the maximum scour depth.