An Experimental Study of Scour Process and Sediment Transport around a Bridge Pier with Foundation

Abstract

Laboratory experiments were conducted on the time development of clear water scour around a non-uniform cylindrical pier in steady flow. The pier comprised a slender cylinder founded on a large cylinder. This study aimed at investigating the effects of foundation depth on the scour process. Three-dimensional topography of the scour was carefully measured using digital stereo-photogrammetry as a method to level a riverbed. The spatial distributions of the sediment transport rate were estimated with the variation in the bed elevation. The results show that the process of sediment transport and scour depends on the foundation depth. The retarding and limiting the scour due to the foundation occur when it is placed at an appropriate level below the initial bed level. The scour depth increases with foundation level when the foundation protrudes above the initial bed level.