River Bed and Bank Stability Using Convex, Concave and Linear Bed Sills

In this study, to examine the effect of a bed sill on river bed scouring, five types of bed sills with nine different configuration patterns were tested in a laboratory flume. To find the optimum sill configuration, the scouring pattern and the depth of the scour hole at the bed was observed downstream of the sill during the experiment. The depth of the scour hole was measured during and at the end of an experiment. It was found that concave and convex configuration patterns with a circular shape and D/W=1. 2 was the most effective sill configuration for protection of both the bed and bank of a river. In particular, the convex pattern was found to be very effective for protection of the center of the river and a concave pattern was very effective for protection of the rivet bank. The results from Particle Image velocimetry (PIV laser) study showed that at the center of the bed sill, the bed sill pushes the wake vortex rings further downstream.