Experimental Model for Studying the Spur Dike Effect on Bridge Abutment Scour in Compound Channel

In this study, the results of experiments conducted in a laboratory model for determining the effect of protective spur dike on bridge abutment scour in compound channel are presented. 75 experiments were carried out in 3 different discharges, five angles and five proportions of the spur dike to the bridge abutment length. The experiments were carried out using sand with uniform granulation and in Froude numbers between 0.44 and 0.49. Laboratory results showed that the bridge's erosion can be reduced to 70% when the spur dike angle is 90 to 120 degrees. At the end, several relationships were proposed to estimate the scour depth. Comparison with other studies showed that the proposed relationship of this research provides a more accurate estimate for the estimation of scour depth in bridge abutment.