抄録
Revetments constructed on river bends must be structurally stronger and more deeply embedded than those on straight river sections, because such revetments are susceptible to damage caused by local scouring. At locations, where likelihood of occurring sever local scouring is high, increasing the embedding depth of revetments will be unfavorable to the execution, and also will increase construction costs. In such situations, measures must be taken to reduce the local scouring. Generally, revetment foundations on straight river sections are protected by constructing bed girdles between the consolidation work, but it is not clear that the bed girdles can play similar roles on bends. It is known that on river bends with gentle slope, vane works effectively prevent the erosion of riverbanks and the local scouring of river bends. However, whether this method can be applied to steep slope rivers is still not well established.
This experimental study examined the following issues focussing on the curvature radius to river channel width ratio (R/B) and the river channel width to water depth ratio (B/H), on the assumption that there are the factors with significant effects on the local scouring. At first, the effects of R/B and B/H on the scouring depth in a bend were clarified and method for determining it was proposed. Next, a comparison of the local scouring with and without bed girdles was performed to examine the function of bed girdles in local scouring reduction, thereby, demonstrating the limits of applicability of bed girdles. Finally, the functions of vane works on a bend in steep slope rivers were studied, proposing their shape and installation method (e. g. height, length, installation angle, and interval) .
