Some observations on the effect of particle shape on the movement of coarse sediments

During a study in which information was gathered to improve the design of unlined canals in coarse granular materials, an opportunity was afforded to study the effect of particle shape on the movement of coarse sediments. This paper summarizes the various measurements and analyses that were made on samples of bed material from several canal sections in the San Luis Valley in Southern Colorado. Some comparisons are made to show the resistance to movement of various shaped particles according to sphericity and Zingg type. It is pointed out that flat particles tend to become imbricated, and they resist movement more than spherical particles of equal weight. Some observations are made on the effect of dilatancy on scour and sediment movement.