Spillway Approach Hydraulics: Difference between revisions
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[[Category:Hydraulic Performance of Spillways]] | [[Category:Hydraulic Performance of Spillways]] | ||
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“Spillway approach configuration will influence the abutment contraction coefficient, the nappe profile, and possibly the flow characteristics throughout the spillway chute and stilling basin. There are three general configurations for the spillway approach, each of which requires a different treatment at the abutments in order to provide acceptable spillway characteristics”. These generally consist of spillways with a deep approach, shallow approach, or confined approach. <ref name="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</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="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</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="EM110-2-1603">[[Hydraulic Design of Spillways (EM 1110-2-1603) | EM 1110-2-1603 Hydraulic Design of Spillways, USACE, 1992]]</ref> | ||
Revision as of 17:48, 2 December 2022
“Spillway approach configuration will influence the abutment contraction coefficient, the nappe profile, and possibly the flow characteristics throughout the spillway chute and stilling basin. There are three general configurations for the spillway approach, each of which requires a different treatment at the abutments in order to provide acceptable spillway characteristics”. These generally consist of spillways with a deep approach, shallow approach, or confined approach. [1]
“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]
“Another factor influencing the discharge coefficient of a spillway crest is the depth in the approach channel relative to the design head... As the depth of the approach channel … decreases relative to the design head, the effect of approach velocity becomes more significant. The slope of the upstream spillway face also influences the coefficient of discharge… the flatter upstream face slopes tend to produce an increase in the discharge coefficient. [1]
Best Practices Resources
Hydraulic Design of Spillways (EM 1110-2-1603) (U.S. Army Corps of Engineers)
Citations:
Revision ID: 4785
Revision Date: 12/02/2022