Ecology, Environment and Conservation Paper

CLEAR WATER SCOUR GEOMETRY AROUND CIRCULAR PIERS

Subhasish Das, Ranadeep Ghosh, Rajib Das and Asis Mazumdar

Abstract

This paper presents an experimental investigation on a series of clear water local scour tests of cohesionless bed sediment conducted in a tilting flume with a circular pier under different pier widths, densimetric Froude number, inflow depth and pier Reynolds number on a sand bed with a mean particle size 0.825 mm. It was observed that the entire scour geometry, that is, scour depth, length, width, area and volume depends on the densimetric Froude number and relative inflow depth. Empirical equations are proposed for the scour depth, scour length, scour width, scour area and scour volume. When the pier diameter increases, approaching flow depth is constant, flow shallowness decreases, and the densimetric Froude number increases. Some empirical equations are proposed based on the results. These equations may be utilized to estimate the scour geometry in future studies.