Location

Portland, OR

Start Date

28-6-2016 1:30 PM

DOI

doi:10.15142/T3340628160853

Description

Crossbar block ramps are hydraulic structures to conquer large river bottom steps via several pool-step-systems. Due to reduced velocities and increased flow depths, fish climb capability can be given. Several authors investigated crossbar block ramp variations to determine flow resistance, energy dissipation and bed stability features on the structure. But also the downstream end of the structure must be taken into account concerning scouring processes to guarantee the structure’s stability and to reduce damage during flood events. The present paper presents a comprehensive experimental investigation program dealing with scouring processes downstream a crossbar block ramp. Influences by ramp slope, discharge and the structure’s geometry are tested. Particularly, for larger discharges and steep slopes massive scouring takes place. With increasing tailwater depth scouring is reduced and hence the structure’s stability is less affected.

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Jun 28th, 1:30 PM

Scouring Processes Downstream a Crossbar Block Ramp

Portland, OR

Crossbar block ramps are hydraulic structures to conquer large river bottom steps via several pool-step-systems. Due to reduced velocities and increased flow depths, fish climb capability can be given. Several authors investigated crossbar block ramp variations to determine flow resistance, energy dissipation and bed stability features on the structure. But also the downstream end of the structure must be taken into account concerning scouring processes to guarantee the structure’s stability and to reduce damage during flood events. The present paper presents a comprehensive experimental investigation program dealing with scouring processes downstream a crossbar block ramp. Influences by ramp slope, discharge and the structure’s geometry are tested. Particularly, for larger discharges and steep slopes massive scouring takes place. With increasing tailwater depth scouring is reduced and hence the structure’s stability is less affected.