水力发电学报2012，Vol.31Issue(3)：119-125,7.
弯道推移质横向输沙规律与床面平衡机理
Bedload transverse transport and bed equilibrium mechanism in river bends
摘要
Abstract
In river bends,sediment transport characteristics,bed topography and bend evolution are directly influenced by bedload movement,such as four typical laws of bedload transport,much more bedload transport from convex reach to convex reach than from concave reach to convex reach,banding transport of bedload,formation of transverse bed slope,and transverse sorting of bedload.This paper sums up five formulas of bedload transverse transport intensity and analyzes its relationship with transverse bed slope using Parker＇s formula.The analysis indicates that the concave-to-convex transport intensity is decreased as the bed slope increases.When the slope reaches a certain value,the intensity will become zero.A further increase of the slope beyond this value will cause a direction change into convex-to-concave transport.The equilibrium mechanism of transverse transport on a steep slope of concave reach generally is different from that on a gentle slope of convex reach.This steep slope often depends on grain submerge weight,transverse circulation,bed particle size and bedload sorting,while the gentle slope depends on upstream incoming sediment,transverse circulation,bed particle size and bedload sorting.Static balancing or moment equilibrium of bedload particles is a key factor that determines equilibrium mechanism.Under the transverse sorting mechanism the bed slope has to adjust itself through a dynamic reiterative process,while bedload sorting always develops to favor reduction of transverse bed slope.关键词
河流动力学/推移质横向输沙/弯道/输沙强度/横向底坡/平衡机理Key words
river dynamics/bedload transverse transport/river bends/transport intensity/transverse bed slope/equilibrium mechanism分类
建筑与水利引用本文复制引用
李志威,方春明..弯道推移质横向输沙规律与床面平衡机理[J].水力发电学报,2012,31(3):119-125,7.基金项目
国家自然科学基金资助项目 （）
