Investigating the effect of curved shape of bridge abutment provided with collar on local scour

(in lingua inglese)

In the present paper, experimental and numerical studies are implemented on a bridge abutment to simulate the local scour depth under the effect of changing the abutment edge shape and collar lengths. 3-D computational fluid dynamic models, which based on finite volume method to solve the Navier– Stokes equations, are created by using SSIIM program. It was found that, the relative scour depth decreases as the relative radius of abutment edge increases. In addition, the reduction percents of local scour depth for r/b = 0 (sharp edge), 0.2, 0.4, 0.6, 0.8, 1.0, 1.4, 2.4, 4.1, and 13.3 are 69%, 87%, 88%, 90%, 92%, 93%, 94%, 95%, 96%, and 95.5% respectively compared to the no-collar case. In addition, the increases of the relative length of collar share to more control and minimize the local scour depth either for upstream or for downstream of bridge abutment.