The flow being discharged from the culvert during flood events leads to significant alterations in the topographical features of the downstream bed. These modifications, manifested as scouring, have the potential to compromise the structural integrity of the culvert. It is therefore greatly important to investigate the factors affecting the extent and the form of scouring downstream. One effective approach to minimizing flow energy, thereby mitigating downstream scour, is the implementation of artificial roughness within the culvert structure. This study examined influences of a box culvert's longitudinal gradient on the topographical variations of the bed downstream in relation to the artificial roughness. Moreover, the outcomes derived from various slope configurations were analyzed in conjunction with scenarios where the culvert was integrated with artificial roughness components and positioned horizontally with a zero slope. A key finding of this research was that the maximum slope examined had a more significant effect on diminishing the maximum scour depth downstream of culvert than the other slopes analyzed did. By inclining the culvert bed, the maximum sedimentation height in the downstream areas was enhanced in comparison to the horizontal culvert configuration. Furthermore, the configurations incorporating an artificial roughness with a height equivalent to 0.13 times the height of the culvert opening demonstrated a significantly advantageous impact toward mitigation of the maximum scour depth. The sedimentation volume and area downstream were observed to undergo reductions in instances where the longitudinal slope of the culvert was greater, in comparison to scenarios with other slopes.
Sadeghpour et al. (Fri,) studied this question.