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  • 學位論文

輸電鐵塔極限能力分析與安全評估之研究

An Investigation on Ultimate Capacity Analysis and Safety Assessment for Transmission Steel Tower

指導教授 : 陳清泉

摘要


我國輸電線路絕大部份為架空形式,而鐵塔為輸電線路中不可或缺之重要支持結構。當鐵塔受災害損壞或倒塌時,小區域破壞往往引發大區域範圍斷電連鎖反應。因此,鐵塔安全與否,大大關係著輸電線路的供電系統是否正常運作。本研究特針對台電公司常使用於345kV輸電線路之懸垂型鐵塔(B5型)與耐張型鐵塔(E5型),當受風時其結構動力行為、非線性行為與極限能力等作深入研究與探討。 首先依弛度分析來建置纜索模型,透過纜索動力分析理論,探討纜索受風擾動之動力行為。參考台電公司「輸電鐵塔新設計標準」決定鐵塔之橫向、縱向及垂直載重,以SAP程式進行結構分析,得到各構件之內力,然後逐步放大側向外力。當結構進入非線性反應,假設儲存於結構內之總體應變能不變,依能量守恆原理進行擬彈性結構分析,求取鐵塔之極限基底側向力與頂層側移值,作為能快速評估鐵塔極限能力之重要參考。其次,應用非線性側推分析法所得之容量曲線與擬彈性結構分析法之評估結果作一比較,並於鐵塔耐震能力評估時採用容量震譜法,以功能績效來表示鐵塔之最大位移及所能承受的地震強度,藉以求出鐵塔之耐震能力指標。另外,利用希伯特-黃轉換(HHT)理論新發展的整體技術理論,如統驗模態分解(EEMD)、統驗希伯特頻譜(EHSP)等技術,及應用雙站頻譜比法的HHT改良識別法,將實際量測鐵塔在架線與非架線狀態時所得之速度歷時資料訊號進行處理,進而識別結構系統之動力特性及頻率之變化來探討鐵塔結構安全、穩定或受損情形。 本文研究成果顯示,應用HHT改良識別法及擬彈性結構分析法,加上非線性側推分析法之結合應用,可以準確的綜合研判及評估輸電鐵塔之動力特性及極限承載能力,進而檢定鐵塔結構之受損程度、穩定性及結構安全。本研究之成果可提供日後對輸電鐵塔安全評估、極限能力分析及結構安全健檢之進階研究開發,具有良好之參考。

並列摘要


Almost all transmission installations are designed for overhead transmission, and transmission lines are linked by steel towers as their supports. Once a tower on the line is damaged or becomes unstable, a large-scale power failure will occur, and consequently huge economic losses may occur. Therefore the safety of steel towers strongly influences the reliability of power supply in transmission lines. In this paper, two different types of tower in Taiwan Power Company (TPC) will be studied and discussed, those are composed of suspension towers (Type B5), and strain towers (Type E5). Their dynamic characteristics, non-linear behavior, and ultimate capacity under wind force will be well studied. The firstly, cable models based on loading and sag condition analysis will be established, and the dynamic characteristics and reactions for cables under wind disturbance will be investigated. According to the specifications of TPC Standard Code, the applied loads on tower in the transverse, longitudinal, and vertical directions will be determined. The secondary, the towers will be analyzed linearly and nonlinearly by using Pseudo-elastic method and nonlinear static pushover analysis associated with SAP program. Finally, the ultimate lateral force, and ultimate drift can be determined. The results presented in this paper for the ultimate capacity of the towers with acceptable accuracy. In addition, our approach is based on the new techniques of Hilbert-Huang Transform (HHT), such as the Ensemble Empirical Mode Decomposition (EEMD), the Ensemble Hilbert Spectrum (EHSP), and the two-station HHT spectral ratio approach. This study is intended to identify the dynamic characteristics from the measured ambient vibration data for the tower, and from which the tower can be assessed to be sound, damaged or unstable from the spectrum appearance after analysis. The new techniques of HHT and nonlinear analysis method associated with pseudo-elastic approach and nonlinear static pushover analysis could be applied to carry out the dynamic characteristics and the ultimate capacity of the towers with acceptable accuracy. The results of this study would be valuable references for the advanced studies in improving design, safety assessment and health monitoring of the transmission towers in Taiwan.

參考文獻


[39] 何象鏞,“含牆鋼筋混凝土結構側推分析之研究”,國立中央大學土木工程學研究所博士論文,王仲宇教授指導,民國96年1月。
[21] 李佳諭、陳清泉,“混合式剛構架耐震能力擬彈性法評估”,結構工程第二十二卷第三期第109-118頁,民國96年。
[78] 李佳諭,“混合式多層構架耐震能力之擬彈性法評估研究”,國立臺灣大學土木工程學研究所碩士論文,陳清泉教授指導,民國88年6月。
[59] Huang, N. E., C. C. Chern, K. Huang, L. Salvino, R. Long, and K. L. Fan, (2001) , “Spectral analysis of the Chi-Chi earthquake data, ” Station TUC129, Taiwan, September 21, Bulletin Seismological Society America, 91, 1310-1338.
[7] Applied Technology Council (ATC),”Seismic Evaluation and Retrofit of Concrete Buildings”, Report No.ATC-40, California, USA, 1996.

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