Author(s): James Yang; Shicheng Li; Par Nilsen
Linked Author(s): James Yang
Keywords: Dam upgrade spillway discharge capacity piano key weir model tests upscaling
Abstract: In Sweden, many dams are to be upgraded to meet the dam-safety guidelines that calls for higher design floods than their existing spillway capacity. In an on-going project, the piano key weir (PKW) is chosen to replace the embankment dam and at the same time enhance the spillway discharge of the facility. In a 2-m wide flume, the proposed PKW configuration on two scales (1:35 and 1:12) is first evaluated, the purpose of which is to clarify the scale effects if any. The former consists of eight (8) units and the latter three (3) units. The models are 3D-printed. The tests show that the 1:35 model exhibits slightly lower discharge capacity, which is presumably due to scale effects. A floor model, on scale 1:35, is then built with machine milling technique to reproduce both the river bathymetry and the spillways including the PKW. It incorporates the existing dam layout with three tainter gates and the PKW consisting of 24.5 units. With the model data upscaled to prototype discharges, the experiments demonstrate that the floor model produces somewhat lower capacity than both the flume models. However, the difference is limited. It is also demonstrated that the machine milling technique leads to better accuracy in model manufacture than the 3D printing. The study provides reference for similar PKW design.
Year: 2025