Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/13246
Title: Outlet works for Branched Oak and Cottonwood Springs Dams, Oak Creek, Nebraska, and Cottonwood Springs Creek, South Dakota : hydraulic model investigation
Authors: United States. Army. Corps of Engineers. Omaha District.
Grace, John L.
Keywords: Branched Oak Dam
Nebraska
Cottonwood Springs Dam
South Dakota
Hydraulic models
Hydraulic structures
Open channel flow
Outlet works
Stilling basins
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-72-1.
Description: Technical Report
Abstract: Model investigations of the outlet works for Branched Oak and Cottonwood Springs Dams were primarily concerned with hydraulic operating characteristics over a wide range of heads. Although the structures were similar in design and purpose, geometric differences required the use of separate model studies, which were conducted with 1:10-scale models that reproduced portions of the approach area, the intake structure, and the outlet conduit. The Branched Oak model also reproduced an SAF impact-type stilling basin and downstream exit channel. Both models indicated undesirable flow characteristics such as nappe flutter, sloshing, and gulping which tended to vibrate the structures. Tests indicated that the flutter could be eliminated by rounding the weir crests; the nappe sloshing could be eliminated by providing a divider-wall between and parallel to the weir crests; and the gulping beneath the cover plate eliminated by placing the cover plate at an elevation above that of the upper pool when the conduit begins to control flow. Performance of the original design SAF basin was satisfactory and the height of the basin training walls was sufficient to prevent overtopping. The exit channel was sloped downward and expanded laterally to permit dissipation of excess energy in turbulence rather than direct attack of channel boundaries. A riprap plan of protection was developed for the recommended exit channel configuration.
Rights: Approved for public release; distribution is unlimited.
URI: http://hdl.handle.net/11681/13246
Appears in Collections:Technical Report

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