Maximum local scour depth at bridge piers and abutments

Abstract

Results of recent laboratory investigations of local scour at bridge piers and abutments are presented. Similarities between the principal vortex occurring in local scour holes at abutments and the horseshoe vortex and downflow at piers are highlighted. Pier and abutment laboratory data, collected near the threshold conditions for sediment movement, display similar trends in the variation of scour depth with length and flow depth. This variation is best described in a three dimensional plot. A simple equation, that can be used to predict the maximum local scour depth at either piers or abutments aligned perpendicular to the flow, is presented and compared with field data.