Numerical Modeling of Flow Field around Bridge Pier with Compound Geometry

Scour generation and its development around bridge piers are the main causes of bridges damage and failure. Understanding the scour mechanism is essential to predict the scour and equilibrium scour hole status around bridge piers. In the recent decades, the use of compound bridge piers instead of the simple piers in construction of bridges, has been developed. In this study, using the FLOW-3D software, process of the formation and development of the scour around bridge pier with compound geometry has been investigated. Numerical results obtained from this model were compared with available experimental data. The results showed that this model had the capability to predict the threedimensional flow field and could effectively provide a better understanding of the experimental studies. The results also indicated the complexity of turbulent flow near pile cap so that these flows were deflected in all directions. On contrary to the simple pier, in which the positive maximum velocity occurred in the sides of pier, in the case of piers with compound geometry this velocity occurred in the center of the pier and downstream of the pile cap.