American Journal of Applied Sciences

Boundary Shear Stress around Bridge Piers

Mirali Mohammadi

DOI : 10.3844/ajassp.2008.1547.1551

American Journal of Applied Sciences

Volume 5, Issue 11

Pages 1547-1551

Abstract

This research presents the measurement of boundary shear stress around the base of some elliptical shaped bridge piers using Preston tube technique. The uniform flow was established and a series of measurements having different discharges and channel bed slopes were undertaken. General results are established and then the effects of flow separation on the hydraulic theory are assessed. The Analysis of results shows that behind the bridge piers (horseshoe area); the amount of boundary shear stress reduces dramatically. The figure for the rate of boundary shear stress of nose to end is about τr = τne = 3.6. It has a remarkable reduction even in steep slopes. The bed shear stress was found to intensify near the nose of the piers. The distribution of boundary shear stress in both mild and steep channel bed slopes along spanwise direction is presented that may give a valuable perspective of the flow action around piers.

Copyright

© 2008 Mirali Mohammadi. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.