抄録
Since groynes are often used for various purposes recently, it is still important to repress local scour around groynes in river management. In this study, a training dike placed in front of groyne is employed as a scour-repression method and the effects of length and location interval were investigated experimentally. The maximum scour depth and scour volume are decreased by putting the training dike. The scour repression rate is increased as the location interval increases. The training dike weakens the deflecting flow at the edge of groyne, and generates the transverse vortex behind it. These two factors affect the scour mechanism around groyne including horse-shoe vortex. In the case of narrow interval, transverse vortex becomes strong, but the deflecting flow becomes weak. In the case of wide interval, the deflecting flow becomes larger again, but horse-shoe vortex in front of the groyne becomes weaker. As a result, local scour is repressed reasonably with an increase of location interval in the range of the present experimental condition.
