Navigation Conditions in Alexandria Reach, Red River Navigation Project, Louisiana. Hydraulic Model Investigation.

摘要

Alexandria Reach is a section of the Red River approximately 87.3 miles upstream of the junction of the Red and Mississippi Rivers. The reach is included in the Red River Navigation Project and will be about 14 miles upstream of Lock and Dam No. 2. There are five bridges in the reach within a distance of less than 2 miles. A fixed-bed model reproducing about 3.5 miles of the river in the vicinity of Alexandria, Louisiana, to an undistorted scale of 1:100 was used to determine navigation conditions through the reach and to develop modifications required to eliminate any adverse conditions indicated. The model investigation was concerned principally with navigation conditions approaching and through the bridges. The high-velocity currents with the water-surface elevations anticipated in the reach indicate that some scouring of the channel bed and changes in channel cross section can be expected with the completed project. Navigation through the reach will tend to be hazardous because of the limited widths of spans divided by a center pier, alignment of the channel and bridge spans, and short distance between some of the spans. Satisfactory navigation conditions would require the use of tows with sufficient power and maneuverability to maintain control and alignment and widths of tows limited to 35 ft.