Available online at www.CivileJournal.org Civil Engineering Journal (E-ISSN: 2476-3055; ISSN: 2676-6957) Vol. 7, No. 05, May, 2021 915 Experimental Studies and Analysis on Mobilization of the Cohesionless Sediments Through Alluvial Channel: A Review Akash Anand 1* , Mubeen Beg 2 , Neeraj Kumar 3 1 Research Scholar, Civil Engineering Department, Aligarh Muslim University, Aligarh, India. 2 Professor, Civil Engineering Department, Aligarh Muslim University, Aligarh, India. 3 Research Scholar, Civil Engineering Department, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, India. Received 14 January 2021; Revised 26 March 2021; Accepted 11 April 2021; Published 01 May 2021 Abstract Entrainment of river bed particles by turbulent flow is a core matter of study in river hydrodynamics. It is of great interest to river engineers to evaluate the shear stress for initiating river bed motion. The main objective is to calculate transport rates for bed load, to predict changes in bed level which are scoured or aggraded and to design a stable channel. Forces acting upon the particle especially fluid forces which give a major role in the incipient motion of the particle on the rough boundary. For calculation generally use shield’s diagram but some other modified methods and approaches are discussed. Modeling criteria are discussed for the hydraulically smooth and rough boundary depending on Reynolds number. In the past, experimental studies on tractive shear stress have been done by many researchers but consideration of lift force to analyze the movement of sediment is very limited. For suspended load transport, a detailed analysis of lift force is required. Based on the study it has been observed that shear stress depends on channel slope not only due to gravitational force but also many other factors like drag force, lift force, friction angle, fluctuations, velocity profile, etc. Complete analysis of these factors provides slope dependency over shear stress. To improve past studies, some factors have been discussed, to give a more correct force balance equation. This is very difficult task to analyze more and more variable’s dependency on the slope. Consideration of the possible number of variable holds complete analysis of experimental study. This paper also reviews the effect of particle Reynolds number and relative submergence over critical shield stress. Keywords: Tractive Shear Stress; Turbulent Flow; Shield’s Diagram; Incipient Motion; Local Velocity; Particle Reynolds Number . 1. Introduction There is the most important problem in the transport mechanism of the sediment is the estimation of the flow intensity at which the movement of the sediment starts. This movement of the grain particles is achieved at a critical level where shear stress is such that it will start the motion. This shear is called critical tractive bed shear stress. It either minimum shear stress responsible for the motion of the grains or bigger size of the grain that comes in motion for a particular value of given shear stress. Forces on bed particle: If the average tractive bed shear stress is not able to move the bed particles, the grains or river bed will be on rest. Hence it doesn't accelerate the river bed because all resultant force on it must be in balance [1-3]. There are 3 main types of forces acting on the particle: * Corresponding author: aanand@myamu.ac.in http://dx.doi.org/10.28991/cej-2021-03091700 © 2021 by the authors. Licensee C.E.J, Tehran, Iran. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/). Review Article