本文主要在探討橋墩於彎道中產生局部沖刷現象，使用「成功人工水草」佈置於橋墩正前方以保護橋墩之局部沖刷坑，並討論配置「成功人工水草」後對彎道外岸沖刷坑的影響。

　　在本實驗中，主要是要探討橋墩置於外岸處的局部沖刷坑，首先，變動橋墩與彎道外岸最大沖刷深度位置之間的相對位置，發現當橋墩置於外岸最大沖刷深度位置之上游方，為彎道外岸處最佳之橋墩設置地點。接下來將「成功人工水草」佈置於橋墩正前方來保護橋墩之局部沖刷坑，變動「成功人工水草」的長度及擺設偏角來觀察對橋墩沖刷坑的保護效果；最後再探討「成功人工水草」擺設地點與橋墩之間距離遠近的關係。

　　由實驗結果得知， 60°為「成功人工水草」最佳之擺設偏角，當左右擺設兩組擺設偏角為60°之「成功人工水草」於橋墩前方時，其保護效率高達69%，並且有調整流場之效果，使外岸沖刷坑沖刷深度降低。而「成功人工水草」距離橋墩最佳之擺設地點為1~1.5倍橋墩直徑D之間的距離，太近或太遠都會減低「成功人工水草」對橋墩沖刷坑的保護效果。

　This paper is to explore the local scour of the pier in a curve channel, and setting CKAW in front of the pier to reduce the scour depth. Then dicussing the influence of the scour hole at outer bank after using CKAW.

　We explore the local scour of the pier at outer bank in the experiment. First, Changing the opposite position from the pier to the maximum scour site, discovered that the best pier position is in front of the maximum scour site. Then setting CKAW in front of the pier to reduce the scour depth, to observe the protection result by changing the length of CKAW and the set angle of CKAW. Finally researching the relationship of the distance between CKAW place site and the pier.

　From the results of my experiment, the best CKAW setting angle is 60°. When we set a pair of CKAW with 60°in front of the pier, the protect efficiency is 69%, and this way of setting CKAW can smooth the
field of fluid, then reduce the scour depth of the scour hole at outer bank. And the best distance between CKAW place site and the pier is 1~1.5 times of the pier diameter.

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