Physics-Based Modeling of Bridge Foundation Scour: Numerical Simulations and Experiments
Abstract
Bridge scour dynamics are dominated by the complex interaction between the approach flow, the erodible bed and the foundation itself. Our basic premise is that fluctuating hydrodynamic forces due to the foundation-induced coherent vortices are responsible for the development of scour holes around bridge piers. This premise was tested here through a series of small scale more detailed laboratory experiments that were carried out at Virginia Tech (with rigid bottom and erodible boundary) and near prototype conditions performed at Waterways Experiment Station (with an erodible boundary). The pier based diameter Reynolds number, ReD, for all these experiments ranged from 26000 to nearly 106. A Digital Particle Image Velocimeter was employed to capture the unsteady dynamics of the flow and a new non-intrusive stereo-photogrammetric technique was developed to reconstruct the three-dimensional scour hole temporal evolution. Post-processing analysis of data reveals an intricate dynamic flow structure in the vicinity of the pier whose behavior is affected by ReD, scour hole stage and possibly bed porosity. Three separate phases of scour hole development were identified, with the initial one occurring more rapidly over a relatively short duration and accounting for nearly 75% of the total excavation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 26, 2013
- Accession Number
- ADA606731
Entities
People
- Clint Dancey
- Panos Diplas
Organizations
- Virginia Tech