非均匀砂沟蚀起动粒径研究

在充分紊流区,推移质泥沙中滑动形式占很大比重,即便是滚动颗粒,通常也并不是起动后一直发生滚动,而是间或发生滑动,因此,有必要研究滑动形式下的泥沙起动机理。本文从泥沙起动概率出发,以床沙及侵蚀物颗粒组成为基础,确定泥沙起动粒径,根据水下泥沙的受力分析,建立非均匀砂滑动平衡方程,利用土槽试验资料确定公式系数,并采用野外实测资料进行验证,结果表明,对于粗颗粒泥沙起动,公式的计算值与实测值符合良好。

Study on particle size of incipient motion for non-uniform sediment in gully erosion

In the sufficient turbulent region, the sliding mode of bed load sediment accounts for a large proportion, and the rolling particle are not rolling usually before ceasing, it also slides in some case. Therefore, it is necessary to research the initiation mechanism of sliding sediment. This study determines the particle size of incipient motion base on incipient probability and particle composition, and establishes sliding equilibrium equation of non-uniform sediment according to force analysis, and defines coefficient of incipient formula based on soil-bin tests. The results of this study reveal that the calculated values of the formulas are in good agreement with the measured values for the coarser sediment initiation.