Local scour at permeable spur dikes

Abstract

In this study, experiments were conducted to investigate the local scour at permeable and impermeable spur dikes extending into the channel at right angle. Based upon dimensional analysis the characteristics of the scour hole at spur dike were correlated to the approach Froude number, the opening ratio of spur dike, the ratio of flow depth to length of spur dike, the ratio of sediment size to length of spur dike and the ratio of channel width to length of spur dike. Also, temporal variations of the depth of scour are presented. The studies have shown that there is considerable reduction in maximum scour depth for permeable spur dikes when compares to those in the corresponding impermeable spur dike situations. Finally, new equations for prediction of the maximum depth of scour and the temporal variations of scour depth around spur dike are presented. © 2008 Asian Network for Scientific Information.