Investigating Effect of Submergence and Angle of Bandal-Like Structure on the Maximum Scour Depth in a Mild 90-Degree Bend

Bandal-like structure is a kind of a spur dike which is a combination of a permeable and an impermeable spur dikes that are usually used in Indian Sub-Continents for riverbank protection and improvement of navigation conditions in alluvial rivers. It is considered as a suitable alternative for these spur dikes. In this research effect of the submergence and angle of the bandal-like structure on the maximum scour depth in a 90 degrees’ mild bend flume was investigated. Therefore, a series of bandal-like structures were placed in the flume with three different angles (60, 90, 120) and three different submergence ratios (1.16, 1.65, 2.15) and were examined under four different Froude numbers (0.21, 0.23, 0.26, 0.29). The results showed that the maximum and minimum scour depths belonged to the bandal-like structures with 90 and 60 degrees angles respectively. Also by increase of the submergence ratio the maximum scour depth was increased.