悬移质分选沉降及其在工程上的应用

Sort Settling of Suspended Load and It's Engineering Application

悬移质泥沙占河流输沙的大部分，由于泥沙的重力作用及水流的紊动混掺的双重作用，悬移质沿垂线的分布呈上稀下浓、上细下粗的规律。在水流的不平衡输沙条件下，超饱和水流中必然有一部分泥沙沉降落淤，其中较粗的泥沙必然率先沉降，较细的泥沙仍随水流悬浮前进。不同粒径的泥沙有不同的沉降距离，利用悬移质的这种分选沉降规律，可以预报水库淤积的形态及位置，渠系沉沙池（条渠）中有害泥沙的排除率。文中举出了两个工程应用的例子，其中涡管排沙式沉沙池已正式运用了两个汛期，排沙效果良好。

The main part of sediment transported by the river flow is the suspended load Under the action of the gravity force on sand particles and turbulent interchange of sediment, the concentration of suspended load along the vertical line is lower and finer in the upper part, and higher and coarser in the lower part Under the non equilibrium sediment transporting, ther e must be a portion of sediment settling and silting on the channel bed in the supersaturated water flow. The coarser parts must settle down first, and different sand grains will have different settling distances Utilizing the sort settling regularity of the suspended load, the form of reservoir sedimentation, the transported percentage of the harmful sediment in silting basin, etc., could be forecasted. Two examples of engineering applications are presented in this paper