著者

市山 誠 石川 忠晴

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:18808751)

巻号頁・発行日

vol.70, no.4, pp.I_727-I_732, 2014

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This study investigated the basic hydraulic characteristics of a bending river section with a cut-off channel by flume experiment. Contents of measurements included the longitudinal profile of water surface, flow velocity in cross sections by an electromagnetic current meter, and the surface flow velocity by using PIV methods. In addition, tendency of bed sediment motion was observed by bottom tracer experiment. Installation of cut-off channel resulted in a wide dead water area at the side of divergence in the main stream and low-velocity area at the center of the confluence. The point of surface flow which attacked the bank moved upstream in the main stream of distribution. Then the secondary flow became stronger, and the direction of bottom flow was strongly skewed in a transverse direction. Moreover, the bottom tracers moved and accumulated rapidly from the outer bank towards the inner bank at the curve of distributaries downstream. It suggested the occurrence of scour and sedimentation.