Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/88386
標題: Pier Scour Prevention with Ring Columns Protection Worksunder Unsteady Flows
變量流流況下環圈柱保護工於橋墩沖刷防治之研究
作者: 王傳益
陳雍讓
楊敏宏
林長葵
何璟浩
Chuan I Wang
Yong Rang Chen
Min Hong Yang
Chang Kuwi Lin
Ching Hao He
關鍵字: 環圈柱保護工;變量流;沖刷減緩率;Ring column protection works;Unsteady flow;Scour depth reduction rate
Project: 水土保持學報, Volume 47, Issue 3, Page(s) 1433-1448.
摘要: 
台灣每年六月至十月之洪水期間,因颱風及滯留鋒面影響往往造成大豪雨,加上台灣溪流坡度陡峭、造成洪水時流速湍急,因此豪雨形成之高洪峰流量常引發橋梁劇烈沖刷,造成橋梁周邊土砂流失,進而危害橋梁安全。近年因颱風造成災害,如2008年卡玫基颱風造成大甲溪后豐大橋落橋事件、2009年莫拉克颱風造成高屏溪雙園大橋落橋等事件。因此本研究基於橋梁基礎安全考量,針對環圈柱橋墩保護工進行相關研究,期能提出減緩橋墩沖刷之新工法,以提供相關單位於工程設計之參考。

本研究利用水工試驗模擬均勻泥砂河床質於中峰型變量清水流流況下,不同配置環圈柱保護工之橋墩沖刷保護效果。針對環圈柱設置之距離(L/b=2、3、4)及環圈柱之高度(h=∆y、y、2y)不同參數條件下,探討環圈柱消除水流動力及降低橋墩之沖刷深度影響,以獲致較佳橋墩保護工之配置模式。研究結果顯示,設置環圈柱保護工均較未設置保護工之橋墩墩前最大沖刷深度為小,顯見環圈柱具減緩橋墩沖刷之功能。而保護工之最佳設置高度為h/b=3.6;最佳設置距離以2倍墩徑為最佳,其橋墩沖刷減緩率為34.3%。

Heavy rainfall frequently occurs during the period of June to October in the summer in Taiwan due to the effects of typhoons and stagnation front. High flowsand typhoon-induced floods frequently result in severe bridge scours and pier foundation damages. For example, typhoon Kalmaegi(2008) and Morakot(2009) caused heavy damages on Ho-Fonbridge in the Da-jiariver and Shuang-Yuan bridge in theKao-Ping river, respectively.To protect the bridge foundation, the use of ring column as a pier scour countermeasure is reported. In this study, hydraulic model experiments with ring column protection works are carried out to search for the ideal arrangements to reduce the bridge scour. It can be served as a reference of design for relevant agencies.

A series of experiments were conducted with uniform sediment under the clear-water advanced unsteady flow conditions to evaluate the effectiveness of different ring column protection arrangements for protecting the bridge. Various parameters,including diameter(L/b=2、3、4), height(h=∆y、y、2y), ring columns protection works were considered in the experiments. Laboratory data are used to assess the influence of each parameter on reducing the kinetic energy of the flow and to propose optimal allocations. Research results show that the maximum scour depth in front of the pier with ring column protection work is less than that without protection work,indicating the ring column protection work obviously has the function of reducing pier scour. It is found that the best pier scour protection results can be obtained when the ring column protection works are set at a height of 3.6 times of the pier diameter, and a distance of 2 times of the pier diameter flow conditions.The corresponding scour depth reduction rate is 34.3%.
URI: http://hdl.handle.net/11455/88386
Appears in Collections:第47卷 第03期

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