A review of the state of research on bridge pier scour under combined action of waves and current

This article presents a review of the state of research on bridge pier scour under combined wave-current flow. The hydrodynamics and scour around the bridge pier under combined wave-current flow have been explained in detail based on the information available in the literature. The impact of relative flow velocity (U-cw), Keulegan-Carpenter number (KC), absolute Reynolds number (R-ea), and sediment characteristics on bridge pier scour under combined wave-current flow is presented. This study includes physical modelling of scour with various formulations to predict scour depth and calculation procedures related to scour under combined wave-current flow in the coastal environment. In addition, this study also provides the development of numerical models to investigate bridge pier scour in detail. In the end, future prospects of hydrodynamics and scour around the bridge pier under combined wave-current flow are delineated.