Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/33537
標題: 懸臂式開口滯洪壩之沖刷試驗研究
A Sudy on the Scouring of the Opening Type Cantilever Flood Detention Dam
作者: 桂代強
Guey, Dai-Chiang
關鍵字: Cantilever;懸臂式;Flood-Detention Dam;Scouring;滯洪壩;沖刷坑
出版社: 水土保持研究所
摘要: 
開口式滯洪壩為在傳統防砂壩溢洪斷面中央部分開一窄而深至下游河床面
之矩形開口。水流在流經矩形開口時,水舌呈豎一字形,而產生一橢圓形
沖刷坑與半弦月形淤積堆。本文乃利用渠槽試驗以六種流量、五種坡度及
三種開口寬來探討懸臂式開口滯洪壩下游之沖刷型態,並與重力式開口滯
洪壩做一比較。經試驗結果顯示,懸臂式壩之流況以堰之分類而言,比較
接近窄頂堰之流況;而重力式壩之流況,則較類似於寬頂堰之流況。在流
量與渠槽坡度愈大時,消能效率愈佳;開口寬度愈大時,消能效率愈差。
流量及渠槽坡度增加時,沖刷深度亦隨之增加。沖刷剖面有二處反曲點,
以四次方程式來模擬,足具代表性,在沖刷剖面前半段呈向下彎曲之型態
,對壩基下有較佳之保護效果。在沖刷深度的比較上,懸臂式壩在流量較
大時,其沖刷深度較重力式壩為小,且在構築成本上亦較重力式壩節省,
所佔腹地面積也比重力式壩為小,因此在坡地社區開發滯洪上,應為一良
好之選擇。

The compound spillway flood detention dam is the traditional
check dam with a narrow rectangular opening down to the
downstream river bed in the center. Owing to the vertical
narrow opening the nappe also presents the same shape. An
elliptical scouring pool and a crescent dune form in the
downstream river bed. In this study, six different discharges
, five different slopes and three kinds of opening widths are
used to find the type of scouring under the situation of
cantilever flood-detention dam in flume experiment, and to
compare them with the gravitational flood-detention dam. From
the results of the experiments. The flow condition of the
cantilever flood-detention dam, according to weir
classification, is similar with narrow-crested weir. Instead
of narrow-crested weir, the flow condition of gravitational
flood-detention dam is similar with broad-crested weir. The
effectiveness of energy dissipation and the depth of scouring
pool will increase if discharge and slope of channel increase.
The wider the opening width is, the smaller energy dissipation
effect will occured. The scouring profile has two anti-curve
point, which expressed by fourth power equation, and the
profile before semi-section is curving downward. It is good
for dam body safety. The scouring depth of the cantilever flood-
detention dam is smaller than that of the gravitational flood-
detention dam . For cost saving, we suggest to use the
cantilever flood -detention dam.
URI: http://hdl.handle.net/11455/33537
Appears in Collections:水土保持學系

Show full item record
 

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.