Summary: | 碩士 === 國立臺灣大學 === 農業工程學系 === 84 === The construction of Sabo dam was often used to river regulation
in upstream watershed of Taiwan. Its discharge formula used in
Handbook of Soil and Water Conservation nowadays was
trapezoidal thin-plate weir formula. From the comparison of
broad-crested weir formula with thin-plate one, the latter
which got a small gauged head would result in lower security.
Hence, the object of this study was to explore the relationship
between the variety of crest length of Sabo dam and the type of
dam, as well as the effect on calculation of discharge for
variety of crest length. After conducting flume experiment and
analyzing test data, this study, under the testing condition,
got the following principal results: 1. The hydraulic
characteristics of Sabo dam belong to that of broad-crested
weir. In the same discharge, the decrease of crest length would
result in lowing gauged head to approaching the curve of
trapezoidal thin-plate weir. 2. If 0.14<h/P<0.48 (or 0.12<h/(h+
P)<0.32) and 0.43<h/L<2.25, the hydraulic characteristics of
Sabo dam should be regarded as that of broad-crested weir. But,
when h/L>2.25 under the same range of h/P, the thin-plate weir
would be referred. From the testing results, the modified
discharge coefficient for different bed slope could be gotten.
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