The introduction of spur dikes into a river flow field can help to improve the stability of a river channel. While the flow velocity directly at the spur dike tip or crest may increase, a large embayment area downstream of the spur dike will form with reduced flow velocities. Due to the increase in flow velocity at the spur dike, a scour hole will form. Many hydraulic structures are tested by building scaled models, which is very costly and lacks versatility to model all factors correctly. The use of two-dimensional numerical models allows for increased efficiency and accuracy of hydraulic modeling. This allows for enhancing relationships between dynamic variables and the estimated scour depth. The length of the spur dike and the flow rate were varied in the experiments. It was found that as the length of a spur dike increases, the depth of the scour also increases. This held a stronger correlation than the increase in flow rate. A relationship was developed between the maximum flow velocity, the upstream flow velocity, and the upstream Froude number to determine the maximum scour depth. This relationship proved to be more accurate than past relationships proposed using data from physical model analysis. The new relationship lowered the percentage-error from 14% to 1% when the predicted scour depths were compared with the measured scour depths. The error was reduced from 7.3% to 1.6% for the long spur dike simulations and from 21.4% to 13.2% for the short spur dike simulations.
展开▼
