Author(s): Fangyi Wang

Linked Author(s): Fangyi Wang

Keywords: Critical bed shear stress; Critical detachment; Non-uniform gravel

Abstract: Methods of prediction of critical bed shear stress for the detachment of non-uniform gravel from stream bed were examined by the application of the relationship derived for the spherical particle. In the process of calculation as a way of determination of the term related to resisting forces included in the relationship for the sphere, an equivalent sphere to the actual gravel is considered. An equivalent equation is considered and used in combination with the relationship for a sphere (d_i) contacting in ideal condition (contacts with two bed-spheres (d_b) in downstream side and protrude from them in arbitrary protrusion rate). The coefficients included in the equivalent equation are determined so that the calculated results by the relationship for the sphere coincide with the criterion relationship which fit in the existing data. In the cases of calculation, two types of equivalent equation and two kinds of region dividing are adopted for comparison. Before discussion of the subject in this paper, summary of the process of calculation and important parts of associated relationships are shortly explained.

DOI:

Year: 2001