Applicability of Open Channel Bed Variation Analysis on A Steep Tunnel

Sediment bypass system has been proposed as a countermeasure against sedimentation and turbid effluence that occur in reservoirs over long period of operation. The system allows both bed load and suspended sediment to bypass the reservoir via a steep-sloped tunnel connecting the upstream of reservoir and the downstream river. In order to provide a guide for rational design of such bypass system, the sediment transport mechanism in a steep tunnel has been studied both experimentally and numerically. The phenomenon observed in the experiment indicates highly unsteady flow, but the analysis method for flows in open-channel with movable bed is found to reproduce overall phenomenon. Better representation of the rapidly changing parts of the flow will further improve results.