Influence of cohesion on suspended load transport of non-uniform sediments

Abstract

Experimental results are presented on suspended load transport rates of clay eroded from a channel bed made up of two types of cohesive sediment mixtures. The first mixture was prepared using fine gravel and clay with the clay proportion by weight varying from 10 to 50%. In the second mixture, equal proportions of fine gravel and fine sand were mixed with clay in proportions of 10 to 50%. Based on dimensional considerations a computational procedure was developed to estimate the rate of suspended load transport of the clay fraction eroded from the cohesive sediment mixtures. In the absence of cohesion, the proposed computational method transforms to a method for computation of suspended load transport rate of the cohesionless sediment mixtures. Studies on suspended load transport rates of cohesive sediment mixtures containing gravel as presented here were not reported so far in the literature to the best of our knowledge.

Keywords:

• Bed shear stress
• Cohesive sediment
• Cohesionless sediment
• Detachment
• Suspended load transport
• Unconfined compressive strength