Hydraulic Model Studies of Crystal Dam Spillway and Outlet Works,Colorado River Storage Project,

摘要

Hydraulic model studies were made to determine the flow characteristics of the Crystal Dam spillway,plunge pool,and outlet works. The initial flip bucket spillway was tested,and the bucket exit modified by extending the 15-foot (4.57-meter) radius beyond the bucket invert to a 4:1tangent at the bucket lip. The modified bucket was required to adequately flip the spillway jet into the plunge pool. A 15-foot (4.57-meter) high deflector wall was placed at the downstream end of the excavated rock plunge pool to deflect the high energy spillway jet from the 3to 1 riprapped slope leading to the downstream river channel. A vortex appearing in the preliminary horizontal bellmouth transition design from the intake towers to the 54-inch (1,371-mm) outlet works conduits was eliminated by raising the floor of the intake tower closer to the invert of the bellmouth. This design was later improved by using one intake tower for both outlet conduits placed at the same elevation. Discharge coefficients are given for both the spillway and the submerged 48-inch (1,219-mm) jet-flow gates.