Experimental Study of Scouring Around a Simple Spur Dike under the Influence of Adjacent Spur Dikes

Erosion of river and coastal edges is one of the major concerns of the hydraulic engineers. Using spur dikes is one of the methods which help to control and reduce the erosion. Spur dikes are used in form of permeable and impermeable that I, L and T-shaped spur dikes are among the impermeable spur dikes. In the present study, optimization of erosion for triple-series spur dikes with simple spur dike in the first position and using different geometries for the second and third positions was studied. Also the best combination for optimizing the amount of erosion was suggested. All the tests were done in the motion-threshold conditions. Results showed that mean scouring depth for simple spur dike in the first position is about 2.7y (y is flow depth). The best and optimal performance between all combinations is related to (I T L) series. Actually, this series is the best combination for reduce the first simple spur dike scouring depth, mean scouring depth and erosion volume of bed. Average bed erosion in the channel middle longitudinal section for (I T L) series is about 0.02y, which illustrated that this combination, in addition to the edges, has good performance in middle of the channel.