Impact of Wing-wall on Scour Development in Box Culverts: Experimental Insights and Predictive Equations

Investigating the downstream bed configuration of culverts is vital for assessing the integrity and performance of hydraulic structures. This study examined the bed topography downstream of a box culvert with a fixed bottom through a series of controlled experiments, investigating the effects of wing-wall angles, particle Froude numbers, and relative tailwater depths on scour. The results reveal that as the experiments approach equilibrium, the fluctuation in maximum scour depth becomes less pronounced, emphasizing the role of temporal factors. Notably, increasing the wing-wall angle results in more extensive scour hole and sediment formations, with significant differences identified between wing-wall angles of 15° and 45°/75°. Additionally, novel equations were developed to estimate critical scour parameters. These findings are crucial for engineers engaged in the design and maintenance of culverts.