Abstract
Factors such as flow and sediment characteristics affecting the spur dike’s local depth of erosion have yielded considerable research results, but there is little discussion of the geometry of the spur dike’s local scour holes. This study focuses on the spatial characteristics of the geometry of local scour holes in straight-wall spur dikes. The discussion shows that the spur dike arrangement clearly changes the plane geometry of the scour hole. The maximum scour depth has a power function relationship with the area of the scour hole and the scour hole-volume. Moreover, the ratio of the product of the maximum scour depth and the plane area of the scour hole to the scour hole-volume is a fixed constant. The average slope of upstream of the scour hole and along the axis direction of the spur dike is slightly larger than the angle of repose of the sediment, the slope distribution of the scour holes profiles presents an inverted “U” type, and its profile morphology and slope distribution have geometric similarity. This distribution also reflected that, the interaction between the downward flow and the horseshoe vortex inside the scour hole leads to the formation of a cusp.
Highlights
Spur dikes are a typical hydraulic structure building, which have the function of protecting river banks from flow scouring and improving the habitat area of aquatic organisms, and are widely used in river regulation and water ecological restoration projects, and so on
Comparing the scour hole profile morphology characteristics of the spur dikes, all of them have geometric similarity, which shows that the relative coarseness and spur dike alignment do not affect the profile morphology characteristics of the hole, and they have geometric similarity
The results show the following: Under clear-water scour conditions, for the vertical wall spur dike with semi-circular type
Summary
Spur dikes are a typical hydraulic structure building, which have the function of protecting river banks from flow scouring and improving the habitat area of aquatic organisms, and are widely used in river regulation and water ecological restoration projects, and so on. Discussion on the problem of scouring, on the one hand, it is conducive to predicting the geometric characteristics of scour hole, including the degree of vertical dimension and longitudinal dimension erosion, for the optimization of spur dike engineering parameters and design, etc. The physical environmental indicators near spur dikes, such as the deep pool/shoal, and the flow structure, are the technical bases for improving the assessment of habitat area of aquatic organisms. The related research results undoubtedly provide technical support for the river regulation and ecological restoration of spur dikes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
