The Effect of Inclined Pair Piers on Bed Topography: Clear Water, Incipient Motion and Live Bed

Abstract

In this study, effects of inclined pair piers on bed topography in a scaled river bend were experimentally investigated. Three separate groups of experiments under clear water, incipient motion and movable bed conditions were performed. The results showed that for a pair of V-shaped piers, the scouring was higher for the pier closer to the bend outer perimeter, while the opposite trend was observed for the Ʌ-shaped piers. It was observed that shifting the position of Ʌ-shaped piers from the 60 degree angle to 90 and 120 degree angles led to 6% and 26% increase in the peak scour depth, while, for the V-shaped piers, the position that led to the maximum scour depth varied depending on the flow regime. The maximum scour depth, which was 117% of the flow depth, was observed in the live bed experiment in which the V-shaped piers were placed at the f 60° plane. Under the live bed condition, it was seen that piers closer to the inner bank are less susceptible to scouring.