Investigating Effect of Netted Collars on Scouring Around Bridge Piers Using Flow-3D

The present study used Flow-3D to investigate the effect of installing netted collars with different shapes on bridge piers. The results showed that installing netted triangular, circular, square, and rectangular collars with a hole diameter of 0.1 (d/D) reduced scouring by 49.5, 52.2, 52.7, and 56.5 percent, respectively, compared to the case with no collars. A hole diameter of 0.15 (d/D) for the same shapes resulted in reductions of 46.1, 43.3, 44.2, and 49.3 percent compared to the case with no collars, respectively, and the reductions for a hole diameter of 0.2 (d/D) were 15.9, 24.8, 26.4, and 26.5%, respectively. Moreover, increasing the collar hole diameter (d/D) intensified scouring, such that an increase in diameter from 0.1 to 0.2 increased scouring by an average of 44.1 percent.