長跨徑橋梁之受風影響甚劇,而風洞實驗為目前認為可靠的研究方法,但最終仍然需要以實場量測來驗證其準確性。本文以目前國內最長之斜張橋-高屏溪橋為標的,於其主跨二分之一處裝置三維風速計與速度計,主跨三分之一處裝設速度計,以風速計量測颱風經過時週遭之風場特性,同時以速度計量測橋梁速度反應,藉此研究橋梁受風之效應。本文利用2007 年柯羅莎颱風經過時所紀錄到的資料進行研究。風場特性分析包括分析其平均風向、平均風速、紊流強度、紊流長度尺度及風速頻譜,結構反應則使用FDD 法分析其結構動力特性,包括自然頻率、阻尼比與模態。結果顯示紊流強度隨著風速提高而減小,而順風向紊流長度尺度有隨風速增加有變大的趨勢,風速頻譜則和Karman 的經驗公式吻合。最後將分析得到之風場特性與結構動力特性代入數值方法中,配合抖振理論模擬橋梁反應,並與實場量測及風洞實驗的結果作比較。 The effect of wind excitation on long-span bridges is extremely significant. Such effect is usually studied and analyzed through wind tunnel test which is one of the most reliable methods. However, the predicted results should be verified by field measurements. This study chose the longest cable-stayed bridge in Taiwan--- Kao-Ping-Hsi Bridge as the target for field measurements. Two 3D anemometers were installed at the middle point of the longer span to measure the wind characteristics. Two sets of velocity censors were respectively installed at the middle point and the one third point of the longer span to measure the dynamic responses of the bridge.
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中華民國第九屆結構工程研討會論文集=Proceedings of The 9th National Conference on Structure Engineering,11頁