“成功人工水草”對彎道中帶工沖刷之保護

"Cheng Kung Artificial Waterweeds" against Riverbed Girdle Scour in a Circular Channel

黃進坤(Chin-Kun Huang) ； 李文仁(Wen-Ren Li) ； 吳虹邑(Hung-I Wu)

《中華水土保持學報》 37卷1期 (2006/03) Pp. 33-42

https://doi.org/10.29417/JCSWC.200603_37(1).0004

摘要

本文利用「成功人工水草CKAW」工法來減少帶工所造成的沖刷現象，以保護帶工安全。試驗在一底床坡度3%的圓形渠道中進行，探討CKAW的導流條長度變化對帶工沖刷保護效率的影響。由試驗結果顯示，導流條長度(L)愈長愈能達到保護的效果，且其保護效率和L/L(下標 d)有一關係存在，L(下標 d)為最大沖刷位置離上游帶工的距離。於彎道中對外岸的保護效果比內岸為佳。當導流條長度大於沖刷坑的範圍時，其保護效率隨著長度快速的增加，在L=4L(下標 d)時，其保護效率可以達到94%，幾乎達到完全的保護功能，顯示CKAW對帶工沖刷具有良好的保護效果。

關鍵字

帶工 ； 沖刷 ； 成功人工水草 ； 彎道

並列摘要

”Cheng Kung Artificial Waterweeds (CKAW)” are adopted to reduce riverbed girdle scouring in this paper. Experiments were carried out in a circular flume to study the effect of protection against scouring with CKAW. We selected a 3% of the initial bed slope with movable sand. Protection efficiency of CKAW (PE) was defined as (The equation is abbreviated) to express the degree of protection; where 8.3 is the maximum scour depth without CKAW, and d(subscript sc) is the maximum scour depth with CKAW. The PE varied with the length of CKAW (L). From the results of the experiments, the PE was more notable as the CKAW's length became longer. The PE in the outer bank is higher than that in the inner bank in the circular channel. The PE is quickly increased while the length of CKAW is over the region of the scour hole, and it reaches as high as 94% in l=4L(subscript d), where L(subscript d) is the distance from the position of the maximum scour to the riverbed girdle. It shows that CKAW may provide excellent protection against riverbed girdle scouring.

並列關鍵字

riverbed girdle ； scouring ； Cheng Kung Artificial Waterweeds ； channel bend