颗粒形状和介质对泥沙休止角的影响

Influence of Particle Shape and Medium on Sediment Repose Angle

泥沙休止角的影响因素主要包括形状、粒径、重率、介质、颗粒级配等,现有的研究主要侧重于粒径、重率、颗粒级配等因素,对于形状和介质对泥沙休止角的影响的研究较少且存在不足。采用筛分法,将天然沙石分为5个不同的粒径组,并将10~15 mm、15~20 mm两个较大粒径组的沙石分为圆球、扁平、椭球3种不同的形状,然后利用自制的抽板泥沙休止角测量仪器测量了泥沙在空气中和水中的休止角。结果表明,粗沙在空气中的休止角大于在水中的休止角,而细沙在水中的休止角大于在空气中的休止角;对于同一粒径组,椭球形的泥沙休止角最大,扁平形次之,圆球形最小。

The major influence factors of sediment angle of repose include particle shape,size,weight ratio,medium,grain composition and so on. The existing researches mainly focus on the influence of particle size, weight ratio and grain composition,as for the researches of parti-cle shape and medium are less and insufficient. In this paper,by sieving method,natural sand was divided into five different particle size fractions. Among them,particle size fractions of 10-15 mm and 15 -20 mm were divided into three different shapes,including pellet,flat and ellipsoid. Then using homemade pumping sediment repose angle measuring instrument, the authors had measured the sediment angle of repose in both air and water. The results show that the repose angle of coarse sand in air is larger than in water, however, as for silver sand, the results are opposite. Besides, for the same particle size fraction, the sediment repose angle of ellipsoid shape is the maximum, followed by the flat shape and the pellet shape is the minimum.