Author(s)

S. F. Alshehri, H. Fouli & S. Ead

Abstract

The objective of this experimental study was to examine the effect of a subsidiary pillar, to be located upstream of bridges, on the development of local scour at a single circular bridge pier. Experiments were conducted to investigate the effect of: a) the spacing between the subsidiary pillar and the bridge pier, b) their relative diameters, and c) the Froude number on the dimensions of the scour hole and its temporal development. The experiments were conducted in a rectangular flume under clear water scour conditions mainly at a Froude number of 0.2 (preliminary experiments were also conducted at Froude number of 0.1 and 0.3). The results show that the maximum scour depth at the pier could be minimized using three different combinations of spacing and relative diameters. A reduction in the maximum scour depth of approximately 50% was possible compared to the pier-alone case. Keywords: local scour, flow altering countermeasures, bridge pier, subsidiary pier, scour hole development.

Keywords

Keywords: local scour, flow altering countermeasures, bridge pier, subsidiary pier, scour hole development.