Author(s): Priscilla Williams, Ram Balachandar, Vesselina Roussinova, Ronald Barron
Linked Author(s): Ram Balachandar
Keywords: Local scour; Pier scour; Scour countermeasures; PIV; Scour protection;
Abstract: Scour and erosion have been well established as the leading causes of bridge failure in North America and as a result, scour mitigation techniques are being explored with increasing frequency. In the absence of scour protection, local scour in the vicinity of the pier progresses unimpeded until a point of equilibrium, reaching appreciable depths and posing a threat to stability. An increased understanding of the influence of scour protection on the flow field around a cylinder in an erodible bed is required in order to develop effective design methodologies for scour protection. The present study investigates the influence of scour mitigation features on the flow field surrounding a submerged cylinder over an erodible bed. Local scour around a submerged cylinder is investigated experimentally. Bed profiles for scour around a submerged cylinder are compared with the results for a submerged cylinder with a horizontal plate surrounding the base of the pier as well as those for a submerged cylinder with a vertical (splitter) plate. Planar Particle Image Velocimetry (PIV) measurements were obtained for the central plane, from the upstream extent of the scour hole to the downstream extent of the primary deposit in the wake of the cylinder. Comparison of mean velocity distribution in the central plane for each experiment is presented.