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散体沙动水休止角是表征沙丘、沙洲等散体沙堆积体稳定形态的重要特征参数,在岸坡稳定分析、坝前冲刷漏斗形态研究中有着广泛的应用。采用室内试验的方法研究了侧向水流作用下不同粒径天然均匀散体沙水下休止角的变化规律。结果表明:在水流流速超过泥沙颗粒起动流速后,天然散体沙水下休止角随流速增大而减小,且减小的速度随着流速的进一步增加而更加迅速;相同流速条件下,粗颗粒泥沙的水下休止角大于细颗粒,其对流速变化的敏感度也低于细颗粒。基于侧向水流边坡上泥沙颗粒的受力分析,引入相对流速概念,初步建立了侧向水流作用下均匀散体沙动水休止角计算公式及其简化形式。
The angle of repose sand repose is an important characteristic parameter to characterize the stable morphology of sand bodies such as sand dunes and sandbanks. It is widely used in the stability analysis of bank slope and the scouring funnel morphology before dam. The indoor test method was used to study the law of angle of repose of natural uniform sand with different particle sizes under lateral flow. The results show that the repose angle of natural bulk sand decreases with the increase of flow rate when the velocity of flow exceeds the initial flow velocity of sediment particles, and the decreasing velocity increases more rapidly with the flow velocity increasing. Under the same flow velocity, Coarse sediment sediment angle of repose is greater than fine particles, its sensitivity to changes in flow rate is also lower than the fine particles. Based on the analysis of the force of sediment particles on the lateral flow slope, the concept of relative velocity is introduced and the formula for calculating the angle of repose of the uniform sand-moving water and its simplified form are established preliminarily.