Bridge pier geometry effects on local scour potential: A comparative study

Abstract

Scour, or the localized loss of soil around the foundation, is a dominant factor contributing to failure. Scour at bridge piers, columns of elevated buildings, and wind turbines with monopile foundations can cause damage after flooding and natural hazards. However, due to the lack of sophisticated modeling, scour is not fully understood. This study utilizes computational fluid dynamic (CFD) simulations to understand the performance of different flow countermeasures in reducing the scour potential. We look at altering the flow around the pier and thereby alleviating the horseshoe vortices and downflow issues. CFD models are developed and validated with available experimental data. The recommended models, with turbulence closures, are employed to predict the bed shear stress for different pier configurations: streamlined shape, tapered sheath, delta vane, and guide wall with slanting vanes. Reductions in the maximum bed shear stress are 30% for both the angled plate and the delta vane, 20% for the tapered sheath, and 15% for the guide wall with slanting vanes. By reducing the bed shear stress, these countermeasures demonstrate their capability to mitigate scour. The proposed solutions have a potential to minimize the accelerated deterioration and protect bridges, elevated buildings, wind turbines, and coastal and offshore infrastructure against scour-induced failures.