Title: Scour and Deposition Around River and Estuarine Bridges
Project Type: Research
Start Date: 03/01/2006
End Date: 02/28/2007
Congressional District: 15th
Focus Categories: Geomorphological Processes, Sediments
Keywords: Scour, Sediment Tranpsort, Bridge, Hydraulics, Deposition
Principal Investigators: Foster, Diane L.; Lippmann, Thomas C.
Federal Funds: $22,185
Non-Federal Matching Funds: $47,512
Abstract: The scour around bridge foundations is the leading cause of bridge failure in the United States. Unfortunately, our present understanding of flow and sediment transport near structures is not complete enough to make accurate predictions of the geomorphology around bridge piles. This limitation is due to both a lack of concomitant field observations of the flow, sediment transport, and geomorphic bed evolution, and in coupling the observations with numerical fluid-sediment models. The objective of this research is to increase our ability to predict how variations in flow conditions will affect the scour and/or deposition of sediment around estuarine and river bridge piles. Two specific goals for this project are to 1) evaluate an existing three-dimensional flow and sediment transport model with field observations of river morphology and flow velocity, and 2) to examine the effect of variations in river stage on bridge scour. Established field sampling techniques (not previously utilized in work of this type) will be used to make measurements of surface and mid-depth flow velocities, and fine-scale river bed evolution in the immediate vicinity of the piles and larger scale topography within about 500-1000 meters up- and down-stream of the bridge. The coupling of detailed field observations with models should lead to a much improved understanding of the scour process, and we anticipate that these results may be used by engineers, scientists, and managers interested in improved parameterization of the sediment transport around structures. The verified model may also be used to identify locations where bridge scour may be problematic under hypothetical flow conditions, or to assess scour in already identified areas of concern.
Progress/Completion Report, PDF