臺灣博碩士論文加值系統

　　在本研究團隊先前證明利用高屏溪斜張橋之微振量測驗證可有效進行沖刷評估的研究基礎上，本論文根據不同環境條件下的較長時間橋墩微振量測，進一步釐清高屏溪斜張橋振態頻率變化與各項環境因素間的關係，並且評估了橋墩沖刷的現況。選定梅雨季節、夏日無雨時期以及颱風期間等不同環境條件下，首先前往高屏溪斜張橋進行多次較長時間的現場橋墩微振量測，由此獲得足供後續比對分析的寶貴訊號。接著採用新近開發的隨機子空間識別技巧，經由改良式穩定圖與分階段篩分程序，根據橋墩訊號精準識別出各振態參數。然後在求出各振態參數隨時間之變化數值後，進一步應用具備系統化停止標準並能有效處理邊界修正的經驗模態分解法，從而系統化決定各振態頻率的基線變化。最後則將各次量測的振態參數變化與車流活載、氣溫及水位等環境因素交叉分析並深入討論。
　　經由這些量測之分析結果，我們首先發現車流活載對各振態頻率的影響明顯超過溫度。考量高屏溪斜張橋主跨為鋼箱型梁且位於高交通量的國道高速公路，其由車流活載所引致之橋體較大振動扮演舉足輕重的角色並不令人意外。更具體地說，白天時龐大的車流活載會增加主梁有效質量，從而降低主梁振態的頻率；反之夜間稀疏的車流活載則讓主梁振態的頻率增加。橋墩振態的頻率也能看得出受到車流活載的影響，只是不如主梁振態頻率密切相關。其次環境溫度隨時間變化的趨勢常與車流活載類似，所以較難區隔兩者各自的影響效果。不過在高屏溪斜張橋，環境溫度對主梁或橋墩振態頻率的影響可確認明顯不及車流活載重要。另外在長期且不規則變動的環境因素方面，確可明確觀察到水位對橋墩振態頻率的影響。由梅雨季及颱風季兩次水位產生變化的量測案例，足以推論在實際基礎沖刷尚未產生但水位因嚴重降雨而明顯上升時，橋墩振態頻率反而可能增大。最後，選取基本上不受水位變化影響的量測案例進行現況沖刷評估，其所推得之橋墩可能沖刷深度仍維持在3.5m左右，反映出四年來應無惡化趨勢。

　　With the recent work by this research group to demonstrate a successful scour evaluation for Kao-Ping-Hsi Cable-Stayed Bridge simply based on ambient vibration measurements, the current thesis further attempts to clarify the variation in the modal frequencies of this bridge induced by several possible environmental factors. Different sets of pier vibration measurements were taken for a longer duration under various environmental conditions including the season of plum rains, regular summer days without rain, and the typhoon period. These signals are first analyzed with an improved stochastic subspace identification techniques where the alternative stabilization diagram and the hierarchical sifting process are newly proposed by this group to more conveniently identify reliable modal parameters. After obtaining the time variation of each identified modal frequency from the continuous pier measurements of several days, a modified empirical mode decomposition algorithm also developed by this group is utilized for systematically extracting the time-varying baselines of different modal frequencies. Finally, the variations of modal parameters identified from each measurement are extensively compared with those of the corresponding traffic load, air temperature, and water level to investigate the environmental effects on the vibration-based approach for scour monitoring.
　　Comparison of the analyzed results in this study elucidates a few important environmental effects on the modal frequencies of Kao-Ping-Hsi Cable-Stayed Bridge. First, it is found that the traffic load is a more dominant factor to alternate the modal frequencies of the bridge than the environmental temperature. Considering that Kao-Ping-Hsi Bridge locates in a super highway and its main span is made by steel box girders, it is not surprising that the high passing traffic would cause substantial bridge vibrations and become the most crucial environmental factor. More specifically, the heavy passing traffic in the day time would increase the effective mass of the bridge deck and consequently decrease its modal frequencies. On the other hand, the light passing traffic around midnight clearly has the reverse effect. It can be further noted that the pier modes are also affected by the passing traffic on the bridge deck, but with a milder correspondence. In addition, the variation of environmental temperature follows a similar trend as that of the traffic, but its effect on changing the frequencies of bridge deck or pier is obviously not as significant for the case of Kao-Ping-Hsi Bridge. As for the effect from the alternation of water level typically associated with the occurrence of bridge scour, it is observed in this study that the modal frequency baselines of the pier modes are very likely to increase with the increasing water level during the season of plum rains and the typhoon period. In contrast, the modal frequency baselines of the pier modes are basically kept constant during summer days without any change in the water level. This observation leads to a possible deduction that the pier frequencies would increase with the increasing water level under heavy rainfalls before serious scour is induced to reduce the height of soil surrounding the foundation. Finally, the evaluation for the current scour status of this bridge is also conducted with the measurement not affected by the fluctuation of water level. The most probable scour depth estimated is the same as that obtained four years ago to indicate that the scour situation does not deteriorate in such a length of time.

目錄
中文摘要　 　　 　 　i
Abstract 　　 　iii
目錄 　　　　　　 　　v
圖目錄 vii
表目錄 xi
第一章 緒論 　　　　 1
　1.1 研究背景及動機 1
　1.2 研究目的與範圍 1
　1.3 文獻回顧 3
　1.4 研究方法與內容 4
　1.5 論文架構 4
第二章 高屏溪斜張橋概述 6
　2.1 橋塔 6
　2.2 主梁 7
　2.3 斜張鋼纜系統 7
　2.4 主梁支承系統 8
　2.5 P2橋墩 9
第三章 高屏溪斜張橋之沖刷評估回顧 10
　3.1 高屏溪斜張橋之主要振態頻率 10
　3.2 有限元素分析模型 11
　3.3 P2橋墩之沖刷評估 12
　3.4 P2橋墩沖刷驗證 13
第四章 隨機子空間識別法 15
　4.1 協方差型隨機子空間識別法 15
　4.2 傳統穩定圖與改良式穩定圖 18
　4.3 分段篩分法之應用 19
　4.3.1 第一階段篩選 20
　4.3.2 第二階段篩選 20
第五章 經驗模態分解法 21
　5.1 篩分程序 21
　5.2 停止標準 23
　5.3 邊界處理 24
第六章 橋墩振態參數識別與環境因素影響評估 28
　6.1 使用儀器及量測配置 28
　6.2 各次現場微振量測說明及結果 29
　6.3 各次橋墩量測之振態頻率與阻尼比識別 30
　　6.3.1 隨機子空間識別法分析流程 30
　　6.3.2 四次量測之各振態頻率與阻尼比識別結果 32
第七章 結論與建議 　　　　　　　　　　　　　　　　　37
　7.1 結論 　　　　　　　　　　　　　　　　　37
　7.2 建議 　　　　　　　　　　　　　　　　　38
參考文獻 　　　　　　　　　　　　　　　　　 　　　　39

[1]石峰，應用現地微振量測進行斜張橋之沖刷評估，國立雲林科技大學營建工程研究所碩士論文，吳文華與陳建州教授指導，2011。
[2]吳文華、陳建州、石峰，應用現地微振量測進行高屏溪斜張橋之沖刷評估與監測，土木水利，第38卷，第3期，第42-51頁，2011。
[3]W.-H. Wu, C.-C. Chen, F. Shih, and S.-W. Wang, Scour evaluation of cable - stayed bridges based on ambient vibration measurements, Proceedings of International Workshop on Structural Health Monitoring and Damage Assessment, Taipei, Taiwan, pp. XI 1-20, 2011.
[4]W.-H. Wu, C.-C. Chen, F. Shih, and S.-W. Wang, Scour evaluation for foundation of a cable-stay bridge based on ambient vibration measurements of superstructure, NDT&E International, Vol. 66, pp. 16-27, 2014.
[5]R.-R. Zhang, R. King, L. Olson, and Y.-L. Xu, Dynamic response of the Trinity River Relief Bridge to controlled pile damage modeling and experimental data analysis comparing Fourier and Hilbert-Huang techniques, Journal of Sound and Vibration, Vol. 285, No.4-5, pp. 1049-1070, 2005.
[6]S. Dey and A.K. Barbhuiya, Velocity and turbulence in a scour hole at a vertical-wall abutment, Flow Measurement and Instrumentation, Vol. 17, No.1, pp. 13-21, 2006.
[7]R. Uzuoka, M. Cubrinovski, H. Sugita, M. Sato, K. Tokimatsu, N. Sento, M. Kazama, F. Zhang, A. Yashima, and F. Oka, Prediction of pile response to lateral spreading by 3-D soil-water coupled dynamics analysis: sharking in the direction perpendicular to ground flow, Soil Dynamics and Earthquake Engineering, Vol. 28, No. 6, pp. 436-452, 2008.
[8]L. Deng and C.-S. Cai, Bridge scour: prediction, modeling, monitoring, and countermeasures-review, Practice Periodical on Structural Design and Construction, Vol. 15, No. 2, pp. 125-134 , 2010.
[9]S. Foti and D. Sabia, Influence of foundation scour on the dynamic response of an existing bridge, Journal of Bridge Engineering, ASCE, Vol. 16, No. 2, pp. 295-304, 2011.
[10]T.-K. Lin, Y.-P. Wang, M.-C. Huang, and C.-A.Tsai, Bridge scour evaluation based on ambient vibration,Journal of Vibroengineering, Vol. 14, No. 3, pp. 1113-1121, 2012.
[11]T.-K. Lin, R.-T. Wu, K.-C. Chang, and S.-C. Yu,Evaluation of bridge instability caused by dynamic scour based on fractal theory, Smart Materials and Structures, Vol. 22, No. 7, 075003, 2013.
[12]X. Kong, C.-S. Cai, and S. Hou, Scour effect on a single pile and development of corresponding scourmonitoring methods, Smart Materials and Structures, Vol. 22, No. 5, 055011, 2013.
[13]L.J. Prendergast, D. Hester, K. Gavin, and J.J. O'Sullivan, An investigation of the changes in the natural frequency of a pile affected by scour, Journal of Sound and Vibration, Vol. 332, No. 25, pp. 6685-6702, 2013.
[14]A. Elsaid and R. Seracino, Rapid assessment of foundation scour using the dynamic features of bridge superstructure, Construction and Building Materials, Vol. 50, No. 1, pp. 42-49, 2014.
[15]Q.-W. Zhang, L.-C. Fan, and W.-C. Yuan, Traffic-induced variability in dynamic properties of cable-stayed bridge, Earthquake Engineering and Structural Dynamics, Vol. 31, No. 11, pp. 2015-2021, 2002.
[16]Y.-Q. Ni, X.-G. Hua, K.-Q. Fan, and J.-M. Ko, Correlating modal properties with temperature using long-term monitoring data and support vector machine technique, Engineering Structures, Vol. 27, No. 12, pp. 1762-1773, 2005.
[17]J.H.G. Macdonald and W.E. Daniell, Variation of modal parameters of a cable-stayed bridge identified from ambient vibration measurements and FE modelling, Engineering Structures, Vol. 27, No. 13, pp. 1916-1930, 2005.
[18]X.-G. Hua, Y.-Q. Ni, J.-M. Ko, and K.-Y. Wong, Modeling of temperature-frequency correlation using combined principal component analysis and support vector regression technique, Journal of Computing in Civil Engineering, Vol. 21, No. 2, pp. 122-135, 2007.
[19]Y.-Q. Ni, J.-M. Ko, X.-G. Hua and H.-F. Zhou, Variability of measured modal frequencies of a cable-stayed bridge under different wind conditions, Smart Structures and Systems, Vol. 3, No. 3, pp. 341-356, 2007.
[20]李愛群、丁幼亮、費慶國、繆長青，潤揚大橋斜張橋模態頻率識別的環境變異性，東南大學學報(自然科學版)，第2期，第245-250頁，2007。
[21]閔志準，孫利民，淡丹輝，影響斜拉橋模態參數變化的環境因素分析，振動與沖刷，第28卷，第10期，第99-105頁，2009。
[22]C.-H. Chen, Y.-Y. Lin, and S.-C. Yang, Variability of dynamic characteristics of a cable-stayed bridge subject to traffic-induced vibrations, Journal of Chung Cheng Institute of Technology, Vol. 39, No. 2, pp. 47-56, 2010.
[23]孫利民、周毅、謝大圻、大跨度斜張橋模態頻率的環境影響因素研究，重慶交通大學學報(自然科學版)，第32卷，第6期，第1106-1110頁，2013。
[24]L. Sun, Y. Zhou, and D. Xie, Temperature effects on modal frequencies of long-span cable-stayed bridges, Proceedings of 4th International Symposium on Life-Cycle Civil Engineering, Tokyo, Japan, pp. 1091-1097, 2014.
[25]孫利民、周毅，謝大圻，環境因素對斜拉橋模態頻率影響的周期特性，同濟大學學報(自然科學版)，第43卷，第10期，第1454-1462頁，2015。
[26]E. Cross, K. Worden, K.Y. Koo, and J.M.W. Brownjohn, Modelling environmental effects on the dynamic characteristics of the Tamar suspension bridge, Proceedings of the 28th IMAC, Jacksonville, USA, Vol. 5, pp. 21-32, 2010.
[27]鄭揚、丁幼亮、李愛群，環境條件影響下懸索橋模態頻率變異性的定量評價，振態與衝擊，第30卷，第8期，第230-236頁，2011。
[28]R. Westgate, Environmental Effects on a Suspension Bridge’s Performance, PhD Thesis, University of Sheffield, UK, 2012.
[29]N.M. Apaydin, Y. Kaya, E. Safak, and H. Alcik, Vibration characteristics of a suspension bridge under traffic and no traffic conditions, Earthquake Engineering and Structural Dynamics, Vol. 41, No. 12, pp. 1717-1723, 2012.
[30]I. Laory, T.N. Trinh, I.F.C. Smith, and J.M.W. Brownjohn, Methodologies for predicting natural frequency variation of a suspension bridge, Engineering Structures, Vol. 80, pp. 211-221, 2014.
[31]R. Westgate, K.Y. Koo, and J.M.W. Brownjohn, Effect of vehicular loading on suspension bridge dynamic properties, Structure and Infrastructure Engineering, Vol. 11, No. 2, pp. 129-144, 2015.
[32]陳明徹，應用隨機子空間系統識別方法探討橋梁結構健康診斷，台灣大學土木工程學研究所碩士論文，羅俊雄教授指導，2012。
[33]J.A. Lopez and M.A. Astiz, An experimental analysis of the evolution of dynamic parameters of a long-span metal arch bridge, Structural Engineering International, Vol. 24, No. 1, pp. 8-19, 2014.
[34]焦志欽、胡利平、韓大建，溫度對橋梁動力特性的影響研究，科學技術與工程，第10卷，第31期，第7685-7689頁，2010。
[35]L. Wang, J. Hou, and J. Ou, Temperature effect on modal frequencies for a rigid continuous bridge based on long term monitoring, Proceedings of SPIE - The International Society for Optical Engineering, San Diego, USA, Vol. 7983, 2011.
[36]王蕾，大跨鋼構-連續梁橋結構性能的運營環境影響與規律分析，哈爾濱工業大學博士論文，歐進萍教授指導，2013。
[37]李嘉维、夏樟華、余印根、林友勤，基於長期動力特性監測數據的大跨度橋梁安全性能評估，福州大學學報，第42卷，第4期，第596-605頁，2014。
[38]余印根，環境溫度對連續剛構橋模態頻率的影響，振動、測試與診斷，第34卷，第1期，第69-76頁，2014。
[39]N.A. Londono, D.T. Lau, and M. Rahman, Characteristics of dynamic monitoring data and observed behaviour of the Confederation Bridge due to operational load variations, Canadian Journal of Civil Engineering, Vol. 40, No. 5, pp. 393-409, 2013.
[40]厲開紋，運用現地監測與結構模擬評估橋梁基礎之沖刷程度與健康狀態，台灣大學土木工程學研究所碩士論文，陳正興教授指導，2012。
[41]林奉廷，橋梁基礎受沖刷之動態行為研究-以新發大橋為例，成功大學土木工程學系碩士論文，陳景文教授指導，2013。
[42]王勝威、吳文華、陳建州、賴國龍，以隨機子空間識別法進行斜張鋼纜之各振態參數識別，第四屆海峽兩岸四地高校師生土木工程監測與控制研討會論文集，呼和浩特，中國，2013。
[43]W.-H. Wu, C.-C. Chen, S.-W. Wang, and G. Lai, Modal parameter determination of stay cable with an improved algorithm based on stochastic subspace identification, Proceedings of 7th European Workshop on Structural Health Monitoring, Nantes, France, pp. 2036-2043, 2014.
[44]W.-H.Wu, S.-W. Wang, C.-C. Chen, and G. Lai, Application of stochastic subspace identification for stay cables with an alternative stabilization diagram and hierarchical sifting process, Structural Control and Health Monitoring, in press.
[45]W.-H. Wu, S.-W. Wang, C.-C. Chen, and G. Lai, Mode identifiability of a cable-stayed bridge under different excitation conditions assessed with an improved algorithm based on stochastic subspace identification, Smart Structures and Systems, in press.
[46]W.-H. Wu, S.-W. Wang, C.-C. Chen, and G. Lai, Appropriate selection of time lag parameter in applications of stochastic subspace identification for several types of civil structures, Mechanical Systems and Signal Processing, in review.
[47]周哲瑋，應用於斜張鋼纜索力受溫度影響分析之快速收斂經驗模態分解法，國立雲林科技大學營建工程研究所碩士論文，吳文華與陳建州教授指導，2015。
[48]周哲瑋、陳建州、吳文華，應用於斜拉索力受溫度影響分析之快速收斂經驗模態分解法，第四屆海峽兩岸四地高校師生土木工程監測與控制研討會論文集，廈門，中國，2015。
[49]W.-H. Wu, C.-C. Chen, J.-W. Jhou, and G. Lai, A rapidly convergent empirical mode decomposition method for applications in analyzing the environmental temperature effects on stay cable force, Digital Signal Processing, in review.
[50]交通部台灣區國道新建工程局，高屏溪橋，2001。
[51]中華民國交通部台灣區國道新建局第二高速公路後續計畫，燕巢至九如段高屏溪河川工程STA. 386+032.81 TO STA. 388+672.70，竣工圖，2000。
[52]B. Peeters, System Identification and Damage Detection in Civil Engineering, Ph.D. Thesis, Department of Civil Engineering, Katholieke Universiteit Leuven, Belgium, 2000.
[53]B. Peeters, G. De Roeck, T. Pollet, and L. Schueremans, Stochastic subspace techniques applied to parameter identification of civil engineering structure, Proceedings of the International Conference MV2 on New Advances in Modal Synthesis of Large Structures, Non-Linear, Damped and Non-Deterministic Cases, pp. 151-162, 1995.
[54]P. Frank Pai, Nonlinear Vibration Characterization by Signal Decomposition, Journal of Sound and Vibration, Vol. 307, No. 3-5, pp. 527-544, 2007.
[55]Y. Dong, Y. Li, M. Xiao, and M. Lai, Analysis of earthquake ground motions using an improved Hilbert-Huang transform, Soil Dynamics and Earthquake Engineering, Vol. 28, No. 1, pp. 7-19, 2008.
[56]G. Kerschen, A.F. Vakakis, Y.S. Lee, D.M. McFarland, and L.A. Bergman, Toward a fundamental understanding of the Hilbert-Huang transform in nonlinear structural dynamics, Journal of Vibration and Control, Vol. 14, No. 1-2, pp. 77-105, 2008.
[57]Q. Xie, B. Xuan, S. Peng, J. Li, W. Xu, and H. Han, Bandwidth empirical mode decomposition and its application, International Journal of Wavelets, Multiresolution and Information Processing, Vol. 6, No. 6, pp. 777-798, 2008.
[58]V. Vatchev and R. Sharpley, Decomposition of functions into pairs of intrinsic mode functions, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 464, No. 2097, pp. 2265-2280, 2008.
[59]J. Xun and S. Yan, A revised Hilbert-Huang transformation based on the neural networks and its application in vibration signal analysis of a deployable structure, Mechanical Systems and Signal Processing, Vol. 22, No. 7, pp. 1705-1723, 2008.
[60]N.-E. Huang, Z. Shen, S.-R. Long, M.-C. Wu, H.-H. Zheng, Q. Yeh, N.-C. Tung, and H.-H. Liu, The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis, Proceedings of the Royal Society of London, Series A: Mathematical, Physical and Engineering Sciences, Vol. 454, pp. 903-995, 1998.
[61]W. Huang, Z. Shen, N.-E. Huang, and Y.-C. Fung, Use of intrinsic modes in biology: examples of indicial response of pulmonary blood pressure to step hypoxia, Proceedings of the National Academy of Science USA, Vol. 95, pp. 12766-12771, 1999.
[62]N.-E. Huang, Z. Shen, and S.-R. Long, A new view of nonlinear water waves: the Hilbert spectrum, Annual Reviews of Fluid Mechanics, Vol. 31, pp. 417-457, 1999.
[63]W. Huang, Z. Shen, N.-E. Huang, and Y.-C. Fung, Nonlinear indicial response of complex nonstationary oscillations as pulmonary hypertension responding to step hypoxia, Proceedings of the National Academy of Science USA, Vol. 96, pp. 1834-1839, 1999.
[64]C.-C. Chen, W.-H. Wu, and C.-Y. Liu, Decomposed Components of the Effective Temperature History and Their Correlation with the Variation of Stay Cable Force, Proceedings of 7th European Workshop on Structural Health Monitoring, Nantes, France, 2014.
[65]http://tisvcloud.freeway.gov.tw/history/TDCS/