远距离输沙明渠不淤流速的研究

我国河流含沙量高，引水明渠的泥沙淤积十分严重，但尚无确定输沙明渠不淤流速的有一定普遍意义的公式，早期对含沙量大小的影响考虑不够、后期不淤流速经验公式大多来自西北地区引黄灌渠的经验，适用于悬移质泥沙较细的情况、黄河洪水泥沙特性表明，含沙量越高、悬沙组成越粗，本文分析及试验验证，得到渠道的不淤流速表达式，充分反映了含沙量及其组成对不淤流速的影响，表明在其他水力因素不变时，输沙明渠不淤流速随着含沙量增加而变化，文中提出的不淤流速公式，可满足黄河高浓度远距离输沙明渠设计的要求。

A study on critical deposit velocity in open channel for long distance transportation of sediment laden flow

At present, the knowledge of critical deposit velocity of heavy sediment laden flow is rather limited. Based on the analysis of characteristics of hyperconcentrated flow and laboratorial experiments, a formula of critical velocity, considering the concentration and composition of suspended material and hydraulic diameter of open channel, is given in this paper. In general, the critical velocity has a maximum, when the sediment concentration reaches to a certain higher value. The impacts of top particle size and sediment concentration of flow on the critical velocity are also discussed in detail in this paper.