Spillway Gate Vibration on Arkansas River Dams

Spillway tainter gates are susceptible to flow induced vibrations particularly when the gate lips are submerged by tailwater levels. Vibrations experienced on the spillway gates of the Arkansas River Navigation Project were severe enough to cause cracks in the structural members and welded connections of the gates. The nature, patterns, and magnitude of the vibrations on these gates were determined and related to the gate openings, tailwater levels, lip designs, seal designs, structural rigidity, and several other factors. Lip design, rubber seal design, and structural flexibility were concluded to be the major causes of gate vibrations. Factors which should be considered in future tainter gate designs to provide vibration-free operation include: (1) lip designs with a clean, sharp flow breakoff point; (2) elimination of rubber gate bottom seals wherever possible; (3) structurally rigid gate lip designs; and (4) testing of unusual gate designs to check for vibration tendencies.