Abstract: Based on the analysis of a large amount of experiment data in this paper, the relationship among the size distribution of nonuniform bed load, bed material and water factors is studied. According to the turbulent velocity following the normal distribution and exchange between bed load and bed material in an equal state in steady sediment transportation, the expression of the size distribution of bed load as well as the calculating methods is obtained by mechanics and mathematics analysis and experiment research. The size distribution curves of bed load calculated by the present method are in good agreement with experiment data.

Key words: size distribution, nonuniform bed load, bed material, gravel-bed stream, exchange, normal distribution

摘要： 本文在大量实验的基础之上,对推移质级配、床沙组成和水力要素三者之间的关系进行了探讨。根据脉动流速服从正态分布和输沙平衡时床沙与推移质泥沙颗粒的交换处于平衡状态的概念,经力学分析、数学推导和试验研究,得到了适合于宽级配非均匀沙河槽的推移质级配计算式和计算方法。用本文方法预报的推移质级配曲线与实测级配曲线吻合良好。

关键词: 颗粒级配, 非均匀推移质, 床沙, 卵石河槽, 交换, 正态分布