Bed-Load Transport at High Shear Stress

High bed shear stresses can be obtained if pressurized conduits are used, and the results of such experimentation are presented herein. In this range existing transport equations diverge rapidly, and the present work indicates that for sand the Einstein bed-load function is not applicable at high shear stress. Previous investigations of the transport of solids as bed-load have generally been carried out in open flumes. The relationships which have been developed, specifically those of Einstein and of Meyer-Peter and Müller, are in fair agreement within the range of the flume data but differ at higher shear stresses. The bulk of the work reported herein was with sand and the results, which were incompatible with the Einstein function, were correlated by an equation with the same form as that of Meyer-Peter and Müller, but with a larger coefficient. Subsidiary testing with nylon did not obey the same correlation, indicating that further testing at high stress is required to determine the effect of specific gravity.