Hybrid Modeling for Design of a Novel Bridge Pier Collar for Reducing Scour

Abstract

Bridge pier scour poses major concerns for public safety and riverine communities because of its ability to undermine pier foundations. A new collar design is introduced as an improvement on the existing Flat Plate Collar (FPC). Uniquely, the three-dimensional collar is specifically designed to contain the horseshoe vortex and guide it safely downstream, while protecting the riverbed around the pier base from the passing accelerated flow. Large shear stresses are thereby prevented from contacting the riverbed, and thus scour is considerably reduced. The collar design was achieved in an iterative hybrid manner through the use of OpenFOAM (CFD) software and by employing experimental tests. Collar designs were tested numerically and adjusted until an improved shape was reached. Then, a physical model of the new collar and an FPC were constructed and tested experimentally. The collar is demonstrated to reduce scour, more than that of an FPC; however further revisions are required for it to be an effective scour solution.