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橋梁沖刷現地模擬與動力試驗 = Field Scour Simulati...
國立高雄大學土木與環境工程學系碩士班

 

  • 橋梁沖刷現地模擬與動力試驗 = Field Scour Simulation and Dynamic Test of a Bridge
  • 紀錄類型: 書目-語言資料,印刷品 : 單行本
    並列題名: Field Scour Simulation and Dynamic Test of a Bridge
    作者: 王鴻諺,
    其他團體作者: 國立高雄大學
    出版地: [高雄市]
    出版者: 撰者;
    出版年: 2011[民100]
    面頁冊數: 121面圖,表 : 30公分;
    標題: 預警
    標題: alarm index
    電子資源: http://handle.ncl.edu.tw/11296/ndltd/28435262316321108939
    附註: 參考書目:面38-43
    摘要註: 近年來因颱風豪雨造成橋梁的損壞,其原因主要是由於橋梁沖刷所引起的基礎裸露。這些橋梁多數未裝設橋梁監測系統,因而無法及時預警封橋。本研究主要是於現場以開挖基礎方式模擬橋梁基礎沖刷情形,再利用現地動力試驗中常用的微動試驗和自由振動試驗獲得橋體在沖刷前後之頻率變化情形,藉以探討沖刷深度與頻率變化之關係。另外,藉由有限元素分析模式,進一步以數值模擬方式探討橋梁沖刷之動力特性,並與現地試驗結果比對。研究結果發現,橋墩基礎的沖刷深度會改變橋梁的固有頻率,而且在不同的沖刷深度下,橋墩的縱向與橫向局部頻率變化最為明顯。因此,橋墩在此兩方向局部頻率變化率可作為橋梁沖刷監測之預警指標。然而,在有限元素模模擬分析方面,必須再進一步的探討邊界條件之正確性,方能更真實的模擬橋梁基礎沖刷的情形。 Recently during the typhoon season there were several bridges were collapse due to heavy storm in Taiwan. The major reason for these collapses of bridges is due to the bridge scoring which may induce the settlement of bridge piers and damaged the bridge foundation. Because lack of bridge monitoring system, it is impossible to send an early warning message to close the bridge.In this study, a field test technique adopted to simulate the scouring foundation of the bridge. The dynamic characteristics of scoring bridge were determined from two field vibration tests, the ambient vibration test and the free vibration test, respectively. The natural frequencies identified from the field vibration test can be compared with those used in finite element analysis. The results indicated that the scouring depth of foundation would significantly change the natural frequencies of the bridge. The variability of natural frequencies can be determined under different scouring depth conditions, which can be addressed in the transverse and longitudinal modes. Therefore, the frequency variation could be as alarm index for monitoring of the bridge scouring. However, the finding implies the finite element model using in designing the structure must be further refined by more realistically evaluating the boundary conditions.
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310002199357 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 541606 1030 2011 一般使用(Normal) 在架 0
310002199365 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 541606 1030 2011 c.2 一般使用(Normal) 在架 0
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