Reduction of Local Scour around Bridge Piers Using Slots and Collars

TLDR

The study investigates using pier slots and collars to reduce local scour around bridge piers. The authors conducted experiments testing slots of varying lengths and attack angles, and collars of different sizes and elevations, to assess their effect on scour reduction. An empirical equation predicting maximum scour depth around circular piers fitted with collars was derived, applicable to uniform sediment in clear‑water flow.

Abstract

The present study examines the use of pier slots and collars for reducing local scour at bridge piers. The efficacy of slots, of different lengths and at different angles of attack, was studied through experiments. The reduction of scour due to the placement of circular collars, of different sizes and at different elevations, was also investigated. Analysis of the data from the experiments as well as data from earlier studies led to an equation for the maximum scour depth around circular bridge piers fitted with collars. The equation applies to local scour of uniform-sized sediment in clear-water flow.