Physical Model Test for Bendway Weir Design Criteria
Abstract
A typical bendway will be molded in a semi-fixed bed flume. The number of weirs, their spacing and submergence will be varied to determine the effects on tows navigating the reach. The designs will be subjected to a range of current velocities and tow sizes. Final guidance will establish minimum required depths over the weirs and recommended spacing relative to the design size tow. During the last decade the U.S. Army Corps of Engineers has been placing structures called bendway weirs (submerged dikes) in river bends to improve stability of navigation channels and, consequently, reduce dredging. In some cases these weirs have improved navigation conditions, especially when physical models have been tested prior to construction to determine efficacy of the designs. However, for many constructed bendway weir systems either no model testing was performed or effects on tow navigation were not considered in their design. In one project physical model test, Montgomery Point Lock and Dam, some designs were tested which were shown by the model to create dangerous conditions for navigation, particularly for upbound tows. Some anecdotal stories from tow pilots concerning a few in-place weir systems have been received which claim difficult navigation conditions at various river stages. Some similar situations have been reported for submerged dike fields in lock approaches.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2002
- Accession Number
- ADA408861