Scour variations around pier groups at a sharp bend with triad vanes

This study applied triad submerged vanes upstream of piers and varied their submergence ratios in order to explore and reduce scouring around piers in a bend. The most important findings are presented as follows: Triad vanes decreased the scour hole volume by a minimum of 22 % in the triad transverse pier and by a maximum of 53 % in the single pier experiment. The highest maximum scour hole reduction was achieved in the longitudinal triad piers with triad vanes for about 35 % in comparison with the case of piers without any vanes. The pier test with three vanes of 50 % submergence ratio resulted in the lowest hole volume, scour area, maximum scour depth and maximum sedimentary ridge of all the tests.