Estimation of maximum scour depth near a spur dike

Abstract

Scour is a natural phenomenon in rivers caused by the erosive action of the flowing water on the bed and banks. Spur dikes are constructed across the flow to protect the bank from erosion by shifting of the river away from the bank. The spur dike undermines due to river-bed erosion and scouring, which is generally recognized as the main cause of spur dike failure. In this study, accuracy of existing equations for the computation of maximum scour depth has been checked with available data in the literature and data collected in the present study using graphical and statistical performance indices. Three new relationships are also proposed to estimate the maximum scour depth and maximum scour length upstream and downstream of spur dike. This new relationship for maximum scour depth is shown to perform better than other existing equations.