ASDSO Dam Safety Toolbox

Grade Control Sill Spillways: Difference between revisions

From ASDSO Dam Safety Toolbox
Jump to: navigation, search
No edit summary
No edit summary
 
Line 6: Line 6:


==Best Practices Resources==
==Best Practices Resources==
{{Document Icon}} [[Design Standards No. 14: Appurtenant Structures for Dams (Ch. 3: General Spillway Design Considerations)|Design Standards No. 14: Appurtenant Structures for Dams (Ch. 3: General Spillway Design Considerations), USBR, 2022]]
{{Document Icon}} [[Design Standards No. 14: Appurtenant Structures for Dams (Ch. 3: General Spillway Design Considerations)|Design Standards No. 14: Appurtenant Structures for Dams (Ch. 3: General Spillway Design Considerations), USBR]]


<!-- For information on notation for in text citations visit https://www.mediawiki.org/wiki/Help:Cite  Or simply enclose the citation as shown <ref> citation </ref> in the location of the in text mention. Citations will automatically populate below-->
<!-- For information on notation for in text citations visit https://www.mediawiki.org/wiki/Help:Cite  Or simply enclose the citation as shown <ref> citation </ref> in the location of the in text mention. Citations will automatically populate below-->

Latest revision as of 19:21, 11 July 2023


Grade control sill spillways are primarily suited for auxiliary and emergency spillways; however, in some cases, they can function as a service spillway. A grade control sill is a less robust, minimal spillway typically limited to a vertical reinforced concrete wall (sill) that is placed in a trench through an excavated trapezoidal channel. The grade control sill can be constructed in both rock and soil foundations. The grade control sill spillway tends to have limited reserve discharge capacity, given channel armorment could be damaged or fail due to discharges that exceed design levels. Therefore, an important consideration is to limit potential erosion during spillway operation. In summary, this type of spillway should only be used on low head situations where the hydraulic drop (vertical dimension between the reservoir water surface and the downstream river or stream) can be effectively controlled, including limiting erosion potential. Examples of grade control sill spillways include the service spillway at Reclamation’s Crane Prairie Dam (embankment) and the emergency spillway at Reclamation’s Davis Creek Dam (embankment).[1]

Best Practices Resources

Design Standards No. 14: Appurtenant Structures for Dams (Ch. 3: General Spillway Design Considerations), USBR


Citations:


Revision ID: 7131
Revision Date: 07/11/2023