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https://hdl.handle.net/11681/13271
Title: | Shoaling conditions in Sawyer Bend and lower entrance to Chain of Rocks Canal, Mississippi River : hydraulic model investigation |
Authors: | United States. Army. Corps of Engineers. St. Louis District. Foster, James E. (James Edward), 1925- Noble, Charles Mark, 1953- Franco, John J. |
Keywords: | Chain of Rocks Canal Sawyer Bend Channel improvement Navigation channels Sediment transport Mississippi River channel improvement Shoaling Movable-bed models Hydraulic models Sedimentation Deposition |
Publisher: | Hydraulics Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
Series/Report no.: | Technical report (U.S. Army Engineer Waterways Experiment Station) ; H-78-7. |
Description: | Technical Report Abstract: This investigation was concerned with the development of an adequate channel and access to the docking facilities along the right bank in Sawyer Bend and the reduction or eli mination of shoaling in the lower entrance to the Chain of Rocks Canal. The alignment of the channel upstream of Mosenthien Island and the movement of sediment from the Missouri River along the right bank caused an increase in flow through the chute channel to the left of Mosenthien Island and shoaling in the channel along the industrial docking facilities in Sawyer Bend. Shoaling in the lower entrance to the canal during low flows has created a serious problem because of the amount of dredging required and the lack of suitable disposal areas. The purpose of the model study was to develop plans that would provide a satisfactory channel in Sawyer Bend and reduce or eliminate the need for dredging in the lower entrance and approach to the Chain of Rocks Canal. A movable-bed model, constructed to scales of 1:250 horizontally and 1:100 vertically, reproduced the Mississippi River and adjacent overbank areas between miles 191.0 and 180.5. Results of the investigation indicated the following : (A.) Development of a satisfactory channel in Sawyer Bend can be accomplished by reducing the amount of flow through the chute channel to the left of Mosenthien Island and forcing the channel to cross toward the right bank farther upstream. This could be accomplished with the plan developed on the model and at the same time maintain some flow in the chute channel during all river stages. (B.) Shoaling in the lower entrance to the Chain of Rocks Canal during low flows is caused by the sudden expansion of the channel width at the lower end of the trail dike which results in the movement of sediment-laden bottom currents into the canal approach channel. (C.) A control gate at the upper end of the trail dike could be used to provide sufficient sediment-free flow into the entrance channel during low river stages which would tend to prevent the bottom currents and sediment from moving around the lower end of the trail dike and into the entrance channel. The effectiveness of the gate would depend on its size and type and method of operation. (D.) A low wing dike at the end of the trail dike could be used to reduce the amount of shoaling in the lower entrance to the Chain of Rocks Canal. The effectiveness of such a structure would depend on flow conditions, elevation and length of the wing dike, and the amount of sediment moving along the river side of the trail dike. (E.) Reduction of flow through the chute channel to the left of Mosenthien Island would tend to decrease the amount of sediment moving along the trail dike and the amount of shoaling in the lower entrance to the Chain of Rocks Canal. NOTE: This file is large. Allow your browser several minutes to download the file. |
Rights: | Approved for public release; distribution is unlimited. |
URI: | http://hdl.handle.net/11681/13271 |
Appears in Collections: | Technical Report |
Files in This Item:
File | Description | Size | Format | |
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TR-HL-78-7.pdf | 11.06 MB | Adobe PDF | ![]() View/Open |