Experimental Analysis of The Effect of Bandal-like Spur Dike Submergence on Bed Topography In 90 Degree Bend

Spur dikes are one of the coastal protection methods. Bandal- like is a local type of spur dikes that would be constructed to improve the water depth for navigation in alluvial rivers. This is a new type of spur dike that is a combination of permeable and impermeable spur dike. The goal of this study was to investigation the effect of Bandal-like spur dike submergence on bed topography. For this purpose, Bandal-like was tested with 3 submergence ratios of (1/16,1/65,2/15) and different hydraulic conditions (0.22,0.235,0.26 and 0.29 Froud number) in mild 90 degree bend. The result show that by increasing of the submergence ratio, scouring around Bandal-like increase too. Also, the results showed that by increasing of the Froude number and densiometric Froude number, the maximum scour depth increases too The investigation of the maximum scour showed that the location of scouring does not match the shear stress pattern in mild bends.