2000 Volume 53 Issue 1 Pages 10-18
In general, sabo facilities are arranged to control sediment directly at the cross section of river. Such facilities disturb flow, sediment transport and passing of fish. From the side of environment, it is necessary to control sediment transport indirectly without cross structures at the flood period.
In this study, the side weir arranged to decrease the discharge at the main channel for the indirectly sediment control. And deposition of sand is expected at the main channel by the decrease of discharge at the main channel. The discharge from the side weir passes through the bypass. Possibility of the indirectly sediment control is showed from the hydraulic experiment and the numerical computation of two-dimensional bed-level variation.
The experiment and the numerical computation were carried out under several cases. The side weir length, height, channel width and discharge were varied to understand the effect of the diversion flow on sand deposit. The relation of discharge and sand volume between the main channel and the bypass were showed by the experiment. The time variation of cross section profile and velocity vectors around the side weir was showed by the numerical computation.
As a result, the influence of the side weir length upon outflow sand from main channel was shown. Sand deposit at the main channel was confirmed from the experiment and the numerical computation. Main deposition area is the sec-tion of side weir on the border of bypass. And possibility of the indirectly sediment control without cross structures was suggested.
