Author(s): Hubert Chanson; Jiayue Hu

Linked Author(s): Hubert Chanson

Keywords: Stepped Spillways; Air-water flows; Concrete gravity dam spillways; Hybrid modelling Mark II; Energy dissipation

Abstract: For the last decades, a number of overflow stepped spillways were built because the staircase shape is conducive to reduced construction costs and increased rate of energy dissipation. Stepped spillways are characterised by highly turbulent airఆ water flows and a significantly larger rate of energy dissipation compared to smooth chutes. Herein, detailed measurements were performed in a largeఆsize 1V:0.8H stepped spillway model and complemented with 1V:0.8H stepped spillway prototype data. The steep slope is typical of modern concrete gravity dams. The laboratory facility was a 15:1 scale model of the large dam's stepped spillway where field observations were conducted between 2013 and 2024. Froude similar experiments were conducted based upon the 2021 flood conditions and detailed twoఆphase flow measurements were undertaken to characterise finely the selfఆaeration and rate of energy dissipation. The hybrid modelling Mark II combined physical and field measurements and it delivered herein a composite approach yielding some robust estimates directly relevant to design engineers.

DOI: https://doi.org/10.3929/ethz-b-000675921

Year: 2024