Spillways: Difference between revisions
Rmanwaring (talk | contribs) No edit summary |
No edit summary |
||
| (14 intermediate revisions by 3 users not shown) | |||
| Line 1: | Line 1: | ||
__NOTOC__ | __NOTOC__ | ||
[[Category:Water Conveyance]] | |||
---- | ---- | ||
<!-- Delete any sections that are not necessary to your topic. Add pictures/sections as needed --> | <!-- Delete any sections that are not necessary to your topic. Add pictures/sections as needed --> | ||
{{Picture | |||
<!-- Add image file name (ex.image.jpg) --> | |||
|image=BDCD.jpg | |||
<!--Add link if applicable --> | |||
|link= | |||
<!-- Add picture caption --> | |||
|caption=Labyrinth weir spillways are commonly used to increase discharge capacity at existing dams. | |||
(Image Source: Gannett Fleming) | |||
}} | |||
“Crest piers, abutments, and approach configurations of a variety of shapes and sizes have been used in conjunction with spillways… Not all of the designs have produced the intended results. Improper designs have led to cavitation damage, drastic reduction in the discharge capacity, unacceptable waves in the spillway chute, and harmonic surges in the spillway bays upstream from the gates. Maintaining the high efficiency of a spillway requires careful design of the spillway crest, the approach configuration, and the piers and abutments. For this reason, when design considerations require departure from established design data, model studies of the spillway system should be accomplished”.<ref name="EM 1110-2-1603" /> | |||
“The basic purpose of the spillway is to provide a means of controlling the flow and providing conveyance from reservoir to tailwater for all flood discharges up to the spillway design flood (SDF). The spillway can be used to provide flood control regulation for floods either in combination with flood control sluices or [[Outlet Works|outlet works]], or in some cases, as the only flood control facility.<ref name="EM 1110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref> | |||
“One of the most common causes of dam failures is the inability to safely pass flood flows. Failures caused by hydrologic conditions can range from sudden failure, with complete breaching or collapse of the dam, to gradual failure, with progressive erosion and partial breaching”.<ref name="[[Fema 94|FEMA 94]]">[[Selecting and Accommodating Inflow Design Floods for Dams (FEMA P-94) | Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow Design Floods for Dams (FEMA-P94), FEMA, 2013]]</ref> | |||
“Crest piers, abutments, and approach configurations of a variety of shapes and sizes have been used in conjunction with spillways… Not all of the designs have produced the intended results. Improper designs have led to [[cavitation]] damage, drastic reduction in the discharge capacity, unacceptable waves in the spillway chute, and harmonic surges in the spillway bays upstream from the gates. Maintaining the high efficiency of a spillway requires careful design of the spillway crest, the approach configuration, and the piers and abutments. For this reason, when design considerations require departure from established design data, model studies of the spillway system should be accomplished”.<ref name="EM 1110-2-1603" /> | |||
==Anatomy of a Spillway== | ==Anatomy of a Spillway== | ||
#[[Spillway Approach | Approach]] | #[[Spillway Approach Hydraulics|Approach]] | ||
#[[Control Section]] | #[[Spillway Control Structures|Control Section]] | ||
#[[Spillway | #[[Spillway Chute Hydraulics|Chute]] | ||
#[[Energy Dissipation]] | #[[Energy Dissipation]] | ||
| Line 22: | Line 35: | ||
#[[Auxiliary Spillways]] | #[[Auxiliary Spillways]] | ||
#[[Emergency Spillways]] | #[[Emergency Spillways]] | ||
See also: [[Hydraulics]] > [[Hydraulic Performance of Spillways]] | |||
==Examples== | ==Examples== | ||
{{Website Icon}} | {{Website Icon}} [https://damfailures.org/case-study/laurel-run-dam-pennsylvania-1977/ Learn about the importance of adequate spillway capacity from the failure of Laurel Run Dam (DamFailures.org)] | ||
==Best Practices Resources== | <noautolinks>==Best Practices Resources==</noautolinks> | ||
{{Document Icon}} | {{Document Icon}} [[Selecting and Accommodating Inflow Design Floods for Dams (FEMA P-94) | Selecting and Accommodating Inflow Design Floods for Dams (FEMA P-94), FEMA]] | ||
{{Document Icon}} [[Technical Release 210-60: Earth Dams and Reservoirs | Technical Release 210-60: Earth Dams and Reservoirs, NRCS]] | |||
{{Document Icon}} [[Engineering Guidelines for the Evaluation of Hydropower Projects: Chapter 2- Selecting and Accommodating Inflow Design Floods for Dams | Engineering Guidelines for the Evaluation of Hydropower Projects: Chapter 2- Selecting and Accommodating Inflow Design Floods for Dams, FERC]] | |||
{{Document Icon}} [[Design Standards No. 14: Appurtenant Structures for Dams (Ch. 1: Introduction) | Design Standards No. 14: Appurtenant Structures for Dams (Ch. 1: Introduction), USBR]] | |||
{{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]] | |||
{{Document Icon}} [[Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420) | Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420), USACE]] | |||
{{Document Icon}} [[Hydraulic Design of Spillways (EM 1110-2-1603) | Hydraulic Design of Spillways (EM 1110-2-1603), USACE]] | |||
==Trainings== | ==Trainings== | ||
{{Video Icon}} [https://youtu.be/TuQUf-nieVY ASDSO Dam Owner Academy: Spillways & Outlet Works] | |||
{{Video Icon}} [[On-Demand Webinar: Inspection and Assessment of Spillways]] | {{Video Icon}} [[On-Demand Webinar: Inspection and Assessment of Spillways]] | ||
{{Video Icon}} [[On-Demand Webinar: Introduction to Addressing Inadequate Conveyance Capacity at Dams]] | |||
{{Video Icon}} [[On-Demand Webinar: Hydraulics 101: Intro to Hydraulics for Dam Safety]] | |||
{{Video Icon}} [[On-Demand Webinar: Hydraulics 201 for Dam Safety]] | |||
{{Video Icon}} [[On-Demand Webinar: Inlet and Outlet Hydraulics for Spillways and Outlet Structures]] | |||
{{Video Icon}} [[On-Demand Webinar: Designing Spillways to Mitigate Failure Modes]] | |||
<!-- 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 18:00, 28 July 2023
|
| Labyrinth weir spillways are commonly used to increase discharge capacity at existing dams.
(Image Source: Gannett Fleming) |
“The basic purpose of the spillway is to provide a means of controlling the flow and providing conveyance from reservoir to tailwater for all flood discharges up to the spillway design flood (SDF). The spillway can be used to provide flood control regulation for floods either in combination with flood control sluices or outlet works, or in some cases, as the only flood control facility.[1]
“One of the most common causes of dam failures is the inability to safely pass flood flows. Failures caused by hydrologic conditions can range from sudden failure, with complete breaching or collapse of the dam, to gradual failure, with progressive erosion and partial breaching”.[2]
“Crest piers, abutments, and approach configurations of a variety of shapes and sizes have been used in conjunction with spillways… Not all of the designs have produced the intended results. Improper designs have led to cavitation damage, drastic reduction in the discharge capacity, unacceptable waves in the spillway chute, and harmonic surges in the spillway bays upstream from the gates. Maintaining the high efficiency of a spillway requires careful design of the spillway crest, the approach configuration, and the piers and abutments. For this reason, when design considerations require departure from established design data, model studies of the spillway system should be accomplished”.[1]
Anatomy of a Spillway
Types of Spillways (Classified by Operation)
Types of Spillways (Classified by Function)
See also: Hydraulics > Hydraulic Performance of Spillways
Examples
Best Practices Resources
Selecting and Accommodating Inflow Design Floods for Dams (FEMA P-94), FEMA
Technical Release 210-60: Earth Dams and Reservoirs, NRCS
Design Standards No. 14: Appurtenant Structures for Dams (Ch. 1: Introduction), USBR
Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420), USACE
Hydraulic Design of Spillways (EM 1110-2-1603), USACE
Trainings
ASDSO Dam Owner Academy: Spillways & Outlet Works
On-Demand Webinar: Inspection and Assessment of Spillways
On-Demand Webinar: Introduction to Addressing Inadequate Conveyance Capacity at Dams
On-Demand Webinar: Hydraulics 101: Intro to Hydraulics for Dam Safety
On-Demand Webinar: Hydraulics 201 for Dam Safety
On-Demand Webinar: Inlet and Outlet Hydraulics for Spillways and Outlet Structures
On-Demand Webinar: Designing Spillways to Mitigate Failure Modes
Citations:
Revision ID: 7471
Revision Date: 07/28/2023