Sediment Incipient Motion Criteria to Redesign Some Rigid Boundary Open Channels in Ramadi City (Iraq)

Abstract

One of the most important factors in the sedimentation process is the beginning of sediment motion. In this paper, sediment incipient motion was studied for channel design purpose, the study made in a laboratory with two kinds of sands, irrigation and sewer types, in rectangular flume cross-section smooth channels. For irrigation and sewer channels, the testing was performed out on five different slopes ranging 0.001-0.003 for irrigation types and 0.0025-0.02 for sewer types.To measure experimental results, shear stress methods, velocity approaches, and the relationship between manning and dimensionless shear stress (Camp Criterion)are applied. The results will be comparewith the Shields and Novak & Nalluri. The results of this study's velocity methods are found to be in good accord with current models.While the shear stress approach yielded an overestimation value  for each type. The design criteria indicate that velocity approach is suitable formula for irrigation, while shear stress is suitable for sewer channel design.