A Study on the Effect of Curvilinear Bed Sill on River Bed Restoration

Bed and bank scouring in a river has great impact on hydraulic structures such as bridges, water intakes and river habitats. In this study, experimental and numerical investigations were conducted to compare the effect of three types of bed sills on flow structure and the scouring pattern and also for understanding the performance of the bed sills. The study revealed that the vortices developed at the banks transfer sediments to the central parts of the channel. It was concluded that concave bed sill enables to stabilize bed at central part of the channel. Other types of bed sills such as sine and wing shapes were also tested and it was found that it is very effective for stabilizing both bed and banks simultaneously. It was found that locations of vortices and depths of scour for sine shape bed sill were changed according to its geometrical specifications. The distances of vortices from the bank were effective in the stability of bed and banks of the channel simultaneously. Furthermore, the results showed that the maximum and minimum of scouring depths occurred at the concave and wing bed sills, respectively.