Experimental comparison of local scouring around single, dual submerged vanes, single bridge pier located at 180 degree sharp bend and without structure

Flow Study in Curved and bended channels in investigation of river morphology has very importance, because natural rivers rarely run in a direct flow and usually travel along an irregular pattern. On the other hand, the construction of any barrier, such as the bridge pier and submerged vanes in front of the current, would prevent local scouring around the barrier. Comparing this scouring to the scouring due to bend-free structure in flows that are near to critical speed can be appealing to river engineers. In this paper, the local scouring of sharp bend has been investigated in laboratory under the influence of individual bridge pier structures and single and double submerged vanes, also this local scouring has been compared with scouring due to bend without hydraulic structure. The results of the experiments showed that the use of two submerged vanes with center-to-center spacing equivalent to the diameter of the single bridge pier, in addition to reduce the scour depth by 30% relative to the single, has great influence in prevention of the sediments progression towards the channel downstream. The discussion about the results of this research is other parts of this article.