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photoThe overtopping test facility is 50 ft high and 5 ft wide with a 2:1 (H:V) slope: typical of an embankment dam. It is capable of providing 32 ft3/s/ft for testing. The overlapping blocks are placed accross the slope avoiding continuous joints in the flow direction.
photoThe blocks were placed shingle-fashion up from the toe of the slope over a free draining filter material.
photoA concrete toe block the fill width of the flume is anchored at the toe of the slope. Every twenty fifth row, a row of blocks are anchored to prevent general bowing of the block overlay as a unit.
photoThis shows a highly aerated nappe flow, with a discharge of 2.8 ft3/s/ft. Notice the spray extending up the walls of the flume. Flow is tumbling over each individual step.
photoData platforms were located across the flume and exteroir to the flume.
photoInvestigators measured total discharge, average bulked water depth, air concentrations, and flow velocities, and pressures on the block surface and in the underlying filters. An air probe and back flushing pitot tube designed by Reclamation were used to determine the air concentration and velocity profiles in the flow.
photoLooking down the flume from the crest showing the development of the boundary layer for the higher flows.