CONTROL OF SAND DEPOSITION IN A RIVERSIDE CONCAVITY ZONE BY USING A SPUR DIKE

Abstract

 The riverside concavity sometimes loses its function by heavy siltation. In this study, a spur dike placed upstream is used to control the sand deposition in a side concavity. The effects of a spur dike on flow structures and sand deposition in a side concavity were investigated experimentally. The length and height of spur dike and the location distance of the spur dike from the upstream end of the concavity zone were changed. The recirculation vortex strength and the exchange coefficient in the concavity become larger by setting spur dike at just upstream of the concavity, but it is slightly reduced when the sur-dike location is far upstream. The morphological shape and total amount of sand deposition were affected by the strength of recirculation vortex and sediment transport rate along the open interface of concavity.