Old River Existing Low-Sill Control Structure, Louisiana; Hydraulic Model Investigation.
Final rept. Jan-Dec 75,
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
Pagination or Media Count:
The Old River Existing Low-Sill Control Structure consists of eleven 44-ft-wide gate bays, Nos. 1-11 from right to left looking downstream, separated by piers. The three center bays low gate bays have a crest elevation of -5.0 ft and the eight outer bays high gate bays, four bays on each side of the center section, have a crest elevation of 10.0 ft. The stilling basin consists of a horizontal apron, divided into three sections, that is surmounted with two rows of staggered 10-ft-high baffles spaced 12 ft apart and terminated with a 3-ft-high vertical end sill. The center section, located downstream of the low gate bays, is 150 ft wide and has an apron elevation of -12.0 ft. The two outer sections, downstream of the high gate bays, are 221 ft wide and have an apron elevation of -5.0 ft. Model investigations were conducted using two 136-scale section models and a 1150-scale section model to evaluate and develop a satisfactory means of regulating the existing structure to achieve the desired flow objectives without creating adverse hydraulic flow conditions. Model tests indicated that partial closure of the gate bays from the top of the structure orifice flow under the gates would be the most effective method of regulating the structure and maintaining satisfactory stilling basin performance and is therefore the recommended plan of regulating the existing structure. The Froude number of flow in the exit channel should not exceed 0.5 for any gate opening downstream of the low bays and 0.4 for gate openings below 11.25 ft and 0.5 for gate openings greater than 11.25 ft downstream of the high bays.
- Hydrology, Limnology and Potamology
- Civil Engineering