Old River Overbank Structure, Louisiana.
Abstract
Physical hydraulic model tests were conducted to investigate the hydraulic performance of the stilling basin and evaluate riprap stability and scour potential with the existing overbank structure. A variety of operating configurations with alternate bays and panels in each of the six bays were used to determine adequate operating conditions and limits of safe operation for the total 73-bay structure. Tests were conducted for the full range of anticipated operating conditions with consecutive bays fully open and fully closed, and with controlled flow through each of these timber panel configurations in each bay of the structure. The stilling basin performance and existing downstream riprap protection were adequate for head differentials of 8.0 ft or less with alternate bays fully open and fully closed (staggered gate operations). However, severe scour occurred around the pier noses immediately upstream of the structure, and the upstream riprap protection was inadequate for headwaters equal to or greater than 66.5 ft with a head differential of 8.0 ft. A 30-in.-thick layer of riprap (weight of the largest stone size = 1,350 lb) was required to prevent severe scour upstream of the structure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1988
- Accession Number
- ADA194978
Entities
People
- Edward D. Rothwell
- John L. Grace
- Noel R. Oswalt