Pier and abutment scour - New laboratory data

Abstract

The purpose of this paper is threefold: (1) Presentation of a scour installation used over the past 6 years; (2) Summary of results pertaining to the Shields entrainment criterion that was expanded for bridge pier and bridge abutment; and (3) Discussion of new results. Based on a long term investigation of scour, the experimental method was improved to result presently in an installation that might be of general interest. Accordingly, details of the set-up are highlighted that allowed the analysis of both the entrainment criterion and the temporal development of bridge scour. Based on a wide range of pier and abutment geometries, various uniform and non-uniform sediments, and densimetric particle Froude numbers up to the threshold condition, both a generalized Shields formulation and an equation for temporal scour progress were derived. These results are readily applicable for design, given the selection of basic parameters in the novel approach. They are highlighted with an example that illustrates also the accuracy of the present approach.