Author(s): U. K. Singh; S. Kumar; Z. Ahmad

Linked Author(s):

Keywords: Bed load; Cohesionless sediment; Equilibrium condition; Gravel particles; Hydraulics; Sediment transport

Abstract: Fluvial hydraulics deals with the process of erosion, transportation, and deposition of sediment in channels by the action of flowing water. This paper presents experimental results on bed load transport rate of gravel particles transported from mobile channel bed made of gravel-silt mixture. Gravel and sand particles were observed transported as bed load due to their coarser size while silt transported as suspended load. Bed load was collected at regular time interval of like 15 minutes, 30 minutes, 60 minutes, etc. Bed surface profile and water surface profile were measured spatially at an interval of 50 cm at the center line of the test section along the flow. It was observed that collected bed load decreases with the time passes and the run was continued till the equilibrium condition i.e., low amount of bed load collected for a long duration and simultaneously bed surface profile and water surface profile come into nearly stable state. This condition is here treated as equilibrium condition as there is no feeding of sediment in the channel and test section also tends to in stable condition with nearly no outflow of sediment. At the end of run, layer of gravel particles was found on the top surface of the channel bed in the mixture of gravel-silt; however, high degradation was observed towards the upstream of test section. A relationship has been developed to compute the total bed load which found in good agreement with the observed data.

DOI: https://doi.org/10.26077/5174-4426

Year: 2022