Three-Dimensional Simulation of Scour-Inducing Flow at Bridge Piers

Presently available formulas for estimating the maximum depth of scour near bridge piers often lead to unreliable results. A fully three-dimensional hydrodynamic model is therefore used in this study to simulate the flow occurring at the base of a cylindrical bridge pier within a scour hole. The results of the numerical simulation are compared with laboratory observations by Melville and Raudkivi (1977). Quantitative and qualitative agreement between the studies is quite good. Discrepancies between the results of the two studies are of an order that may be attributed to choices in numerical model parameters. The simulations may be supplemented by Lagrangian particle-tracking to estimate the depth of the equilibrium scour condition.