The initiation of sediment motion in fixed bed channels

Document Type: Research Paper



The transport of sediment in open channels is a complex process, and the physics of this phenomenon have not been completely explored. The majority of research work on sediment transport has been concentrated on beds formed of the same mobile sediment and only a few researchers have been concerned with sediment motion over fixed bed. This paper reviews the state of the problem and focuses on some practical points. Sediment threshold experiments were conducted in the two types of V-shaped bottom channels. Sand and gravel particle movements were considered and the relationship between flow discharge and bed shear stress, as well as channel bed slope were found at the threshold condition. Some practical and design equations were found to be more appropriate. It may be found that the effect of cross sectional shape on sediment threshold in fixed bed channels should be examined