Experimental study on measurement method of gravel discharge rate in highspeed flow using plate-type sensor

Abstract

A sediment bypass tunnel is used as one of the methods of sediment management for reducing the sedimentation of the dam reservoir and conserving and improving the sediment transport downstream of the dam. Measurement of the amount of sediment passing through the sediment bypass tunnel is important for operation and maintenance of the facility concerning abrasion damage, examination and evaluation of riverbed environmental change of the downstream river. Therefore, considering the application to the Koshibu Dam sediment bypass tunnel, the authors are investigating measurement method of gravel flow amount in high-speed flow. The sediment bypass tunnel began test operation in the autumn of 2016 at the Koshibu Dam built in the Koshibu River, the tributary of the Tenryu River in Japan. In this paper, the authors report the results of examining the response characteristics and measurement method of the plate-type sensor against gravel flow by the flume experiment reproducing high speed flow of about 10 m/s.