Development of scour hole depth around setback abutment in a compound channel

• Published in: Water and environment journal : WEJ 2022-02, Vol.36 (1), p.18-29
• Main Authors: Abouelfetouh Abdelaziz, Ahmed, Lim, Siow Yong
• Format: Article
• Language: English
• Subjects: compound channel; Compound channels; Depth; Empirical equations; Equilibrium; equilibrium time; Exponential functions; Mathematical analysis; maximum scour depth; Scour; scour hole; Scouring; setback abutment
• ISSN: 1747-6585; 1747-6593
• DOI: 10.1111/wej.12758

This study focuses on scour depth development around 45° wing‐wall setback abutments in a compound channel. The results show that the scour development curves almost have similar shape and they can be described using exponential function. It is generally observed that the scour hole achieved 80% of the equilibrium scour depth at a scour time equals to 25% of the equilibrium scour time. Additionally, an increase in the relative abutment length and the contraction ratio causes an increase in the equilibrium time. However, this time decrease with increasing flow depth ratio. Finally, new empirical equations are proposed to predict the development of scour depth and the time to reach the equilibrium state. These equations will be useful to predict these characteristics of scour hole especially for setback abutments in compound channel and predict the temporal development scour depth for previous studies that have available data related to maximum scour depth.