預鑄生態石塊應用在灌排水路之設計

The Design of Pre-cast Ecological Concrete Slabs for Irrigation Canals

陳獻(Shinne Chen) ； 楊紹洋(Shaw-Yang Yang) ； 詹榮鑑(Jung-Chien Chan)

《農業工程學報》 51卷2期 (2005/06) Pp. 75-85

https://doi.org/10.29974/JTAE.200506.0006

摘要

本研究以預鑄生態石塊應用在灌排水路為主題，考慮水路渠面為平面、凹面、及凸面等三種預鑄石塊，試驗時以渠道水深為主要考量、流速為輔，以光滑平面渠道為基本資料，比較凹面和凸面等兩種渠道的水理特性。試驗結果顯示，常態流速和水深下，渠道曼寧係數大小為凸面＞凹面＞平面，而流量和水深較小時，渠道曼寧係數較大。相同流量下，渠道曼寧係數隨著渠坡增加而增大。流速分佈圖顯示，凸面渠道有較大歧異性之流速分佈，凹面渠道次之，平面渠道流速分佈最為均勻。在渠道水中溶氧量方面，凸面和凹面渠道試驗段溶氧量均高於入口處，相對水中溶氧量平均約增加2.5%，且凸面渠道水中溶氧量均較凹面渠道為大。就輸水效率和生態特性而言，凹面渠道具有較小的曼寧係數，且能提供良好的水域生態環境，較傳統凸面渠道具有更佳的生態性。本研究設計之預鑄生態石塊可應用於現地生態材料取得不易或場鑄施工不便的處所，水工模型試驗所獲得的渠道曼寧係數，有助於生態水路流量的設計，水理特性和溶氧量等參數可做為灌排水路生態化改善工程的參考。

關鍵字

灌排水路 ； 生態工法 ； 水工模型試驗 ； 預鑄生態石塊 ； 曼寧係數

並列摘要

This research tries to apply the pre-cast ecological concrete slabs to the construction of Irrigation canals. The main study is the design of pre-cast ecological concrete slabs. This study provides the analyses of hydraulic properties, the estimate of Manning coefficient by hydraulic model test, and the measurement of dissolved oxygen with the considerations of convex, convex, and smooth surfaces of canals. When experiment takes the channel water depth as the main consideration; the velocity of flow is auxiliary. Taking the smooth plane canal as the basic document compared with the experimental results of concave and convex canals. Under the normal velocity and water level, the experimental results show that the Manning coefficients are the convex＞concave＞smooth planes. The Manning coefficient is rather larger when the flux and the water depth are small. Under the same flux, the Manning coefficient increases with the slope increasing. From the velocity distribution, the canal with convex plane produces the largest diversity of velocity distribution, the one with concave plane gives the second, and the one with smooth plane yields the smallest among these three velocity distributions. For the dissolved oxygen, the test sections of convex and concave canals can be obtained larger dissolved oxygen than that of exit section. The dissolved oxygen in the water of canal increases about 2.5%. In addition, the dissolved oxygen of convex canal is larger than that of concave canal. From the points of transported efficiency and ecological property, the canal with concave plane gives less Manning coefficient and provides the better ecological environment of aquatic area. The ecological property of concave canal is superior to that of traditional convex canal. Also, the design of pre-cast ecological concrete slabs can be applied to the place short of natural materials or inconvenient to build on site. The analyses of hydraulic properties, the estimate of manning coefficient through the hydraulic model test, and the measurement of dissolved oxygen will be helpful for the design of flow rates and the construction improvement of irrigation canals.

並列關鍵字

Irrigation canal ； Ecological engineering method ； Hydraulic model test ； Pre-east ecological concrete slab ； Manning coefficient