Abstract:

This paper derives formulas for calculation of the relative contraction of water depth and the relative hydraulic jump depths in the most unfavorable condition, based on the energy dissipation formulas given in the sluice design specification. Because the most unfavorable state of energy dissipation for sluice generally occurs not at the maximum flow, engineers often blind spreadsheet deriving for stilling basin depth design. We apply the extreme value theory and dimension theory to analyze the most unfavorable stilling basin depths, and suggest concise formulas for three stilling basins of coastal tidal drainage gate, sluice on a plain river, and sluice with a great water drop on a mountain river. Example calculations show that these formulas are accurate, reliable, and convenient.