有鑒於台灣地理位置之影響，易受到颱風、地震等環境災害影響，近年來發生多起豪雨引起之洪水災情，強勁水流沖襲橋墩與基礎，進而導致基礎裸露及墩柱傾斜倒榻，最嚴重的情況甚至是造成上部結構斷裂而產生傷亡，為盡力避免傷亡再次產生，因此對現行橋梁的安全性分析即為本文之研究目的，以位於高雄市甲仙區之甲仙大橋為研究對象，進行橋梁結構的模擬分析，透過工作模態分析實驗，在環境振動作用之下，使用加速度規量測各跨橋梁之微振反應，並以峰值挑選法、頻率域分解法以及協方差型隨機子空間識別法進行橋梁結構模態參數的識別，以識別結果之模態頻率及振形為校正依據，與依照工程設計圖面建置之初始有限元模型進行比對，初始模型一般受到模型精細度與實際結構的複雜化和劣化等因素，使得有限元模擬與實際量測結果之動態特徵存在誤差，文中透過模型更新的方式，對於節點剛性與構件尺寸和材料參數等項目進行調整，以期達到降低有限元模型與現地量測結果間之誤差，進而提升模型之有效性及代表性，使其能夠可信地模擬出實際橋梁結構之動態與靜態力學行為與反應，並於研究中考慮不同情況下之情境與載重模擬。

Because of Taiwan's geographical location, there cause environmental disasters as typhoons, earthquakes, etc. In recent years, floods disaster occurred by the heavy rain. Floods rushed piers and foundations, and led to them tilt down. It even caused the upper structure fractured resulting in casualties. To try to avoid casualties happen again, so the research purpose is the safety analysis of Jia-Sian Bridge which located in Taiwan, Kaohsiung, Jia-Sian district. Through the operational modal analysis method, under the ambient vibration, uses acceleration sensors to measure micro-vibration response of bridge. Then there use peak picking method, frequency domain decomposition method and covariance-driven stochastic subspace identification method to identify modal parameters of bridge. According to the experiment result, there compare with initial finite element model which built on the basis of engineering drawings to verification model. But initial model exists deviation because of model accuracy and complex structural factors, there cause model parameters error with the finite element simulation and the actual measurement result. This research through the model update, it adjust the stiffness of joints, component dimensions, and material parameters to achieve lower error between the actual results and the model. Thus, it will enhance the effectiveness and representative of the finite element model, so that the updating model can credibly simulate dynamic and static behavior of the actual structure, and also can simulate the different environmental situations or load combination.

1.Ewins D. J. (1984), Modal testing: Theory and practice, New York: John Wiley & Sons, Inc.
2.Van Overschee P. and De Moor B (1996). Subspace Identification for Linear Systems: Theory-Implementation-Applications, Netherlands: Kluwer Academic Publishers.
3.Bendat J. S., Piersol A. G. (1993), Engineering Applications of Correlation and Spectral Analysis, New York: John Wiley & Sons, Inc.
4.Peeters B. (2000), System Identification and Damage Detection in Civil Engineering, Ph.D Thesis, Katholieke University, Leuven, Belgium.
5.Bendat J. S., Piersol A. G. (1999), Random data: Analysis and measurement procedures, New York: John Wiley & Sons, Inc.
6.Van Overschee P., De Moor B (1991). “Subspace Algorithm for the Stochastic Identification Problem”, Proceedings of the 30th IEEE Conference on Decision and Control, pp. 1321-1326.
7.Lauzon, R. G., & DeWolf, J. T. (2006). Ambient Vibration Monitoring of a Highway Bridge Undergoing a Destructive Test. Journal of Bridge Engineering, 11(5), 602-610.
8.Abdel‐Ghaffar, A. M., & Scanlan, R. H. (1985). Ambient Vibration Studies of Golden Gate Bridge: I. Suspended Structure. Journal of Engineering Mechanics, 111(4), 463-482.
9.Felber, A., & Cantieni, R. (1996). Advances in Ambient Vibration Testing: Ganter Bridge, Switzerland. Structural Engineering International, 6(3), 187-190.
10.Farrar, C. R., & James Iii, G. H. (1997). System Identification from Ambient Vibration Measurements on a Bridge. Journal of Sound and Vibration, 205(1), 1-18.
11.Bayraktar, A., Türker, T., & Altunişik, A. C. (2015). Experimental frequencies and damping ratios for historical masonry arch bridges. Construction and Building Materials, 75, 234-241.
12.Whelan, M. J., Gangone, M. V., Janoyan, K. D., & Jha, R. (2009). Real-time wireless vibration monitoring for operational modal analysis of an integral abutment highway bridge. Engineering Structures, 31(10), 2224-2235.
13.Magalhães, F., Caetano, E., & Cunha, Á. (2008). Operational modal analysis and finite element model correlation of the Braga Stadium suspended roof. Engineering Structures, 30(6), 1688-1698.
14.Brownjohn, J. M. W., Magalhaes, F., Caetano, E., & Cunha, A. (2010). Ambient vibration re-testing and operational modal analysis of the Humber Bridge. Engineering Structures, 32(8), 2003-2018.
15.江哲豪(2006)，「頻率域分解方法在結構模態參數分析之應用」，國立中央大學土木工程研究所碩士論文。
16.陳明徹(2012)，「應用隨機子空間系統識別方法探討橋梁結構健康診斷」，國立台灣大學土木工程研究所碩士論文。
17.Altunişik, A. C., Bayraktar, A., Sevim, B., & Özdemir, H. (2011). Experimental and analytical system identification of Eynel arch type steel highway bridge. Journal of Constructional Steel Research, 67(12), 1912-1921.
18.Altunişik, A. C., Bayraktar, A., & Sevim, B. (2011). Output-Only System Identification of Posttensioned Segmental Concrete Highway Bridges. Journal of Bridge Engineering, 16(2), 259-266.
19.Peeters, B., & De Roeck, G. (2001). One-year monitoring of the Z24-Bridge: environmental effects versus damage events. Earthquake Engineering & Structural Dynamics, 30(2), 149-171.
20.Sikorsky, C. S., Stubbs, N., Bolton, R., Choi, S., Karbhari, V. M., & Seible, F. (2001). Measuring bridge performance using a structural health monitoring system, Smart Structures and Materials 2001: Smart Systems for Bridges, Structures, and Highways, July, Newport Beach, CA, USA, Proc. SPIE 4330, pp.179-190.
21.Costa, B. J. A., Magalhães, F., Cunha, Á., & Figueiras, J. (2014). Modal Analysis for the Rehabilitation Assessment of the Luiz I Bridge. Journal of Bridge Engineering, 19(12), 05014006.
22.Zanardo, G., Hao, H., Xia, Y., & Deeks, A. J. (2006). Stiffness Assessment through Modal Analysis of an RC Slab Bridge before and after Strengthening. Journal of Bridge Engineering, 11(5), 590-601.
23.Calçada, R., Cunha, A., & Delgado, R. (2002). Dynamic Analysis of Metallic Arch Railway Bridge. Journal of Bridge Engineering, 7(4), 214-222.
24.Benedettini, F., & Gentile, C. (2011). Operational modal testing and FE model tuning of a cable-stayed bridge. Engineering Structures, 33(6), 2063-2073.
25.Bayraktar, A., Birinci, F., Altunışık, A. C., Türker, T., & Sevim, B. (2009). Finite Element Model Updating of Senyuva Historical Arch Bridge Using Ambient Vibration Tests. The Baltic Journal of Road and Bridge Engineering, 4(4), 177-185.
26.Ren, W.-X., & Peng, X.-L. (2005). Baseline finite element modeling of a large span cable-stayed bridge through field ambient vibration tests. Computers & Structures, 83(8-9), 536-550.
27.Hasançebi, O., & Dumlupınar, T. (2013). Linear and nonlinear model updating of reinforced concrete T-beam bridges using artificial neural networks. Computers & Structures, 119, 1-11.
28.Feng, M. Q., Kim, D. K., Yi, J.-H., & Chen, Y. (2004). Baseline Models for Bridge Performance Monitoring. Journal of Engineering Mechanics, 130(5), 562-569.
29.Hu, W.-H., Caetano, E., & Cunha, Á. (2013). Structural health monitoring of a stress-ribbon footbridge. Engineering Structures, 57, 578-593.
30.Cunha, A., Caetano, E., & Delgado, R. (2001). Dynamic Tests on Large Cable-Stayed Bridge. Journal of Bridge Engineering, 6(1), 54-62.
31.Morassi, A., & Tonon, S. (2008). Dynamic Testing for Structural Identification of a Bridge. Journal of Bridge Engineering, 13(6), 573-585.
32.Türker, T., & Bayraktar, A. (2014). Structural safety assessment of bowstring type RC arch bridges using ambient vibration testing and finite element model calibration. Measurement, 58, 33-45.
33.Huang, M., Guo, W., Zhu, H., & Li, L. (2008). Dynamic test and finite element model updating of bridge structures based on ambient vibration. Frontiers of Architecture and Civil Engineering in China, 2(2), 139-144.
34.Costa, B. J. A., Magalhães, F., Cunha, Á., & Figueiras, J. (2013). Rehabilitation assessment of a centenary steel bridge based on modal analysis. Engineering Structures, 56, 260-272.
35. Wang, H., Li, A.-q., & Li, J. (2010). Progressive finite element model calibration of a long-span suspension bridge based on ambient vibration and static measurements. Engineering Structures, 32(9), 2546-2556.
36.Sanayei, M., Phelps, J. E., Sipple, J. D., Bell, E. S., & Brenner, B. R. (2012). Instrumentation, Nondestructive Testing, and Finite-Element Model Updating for Bridge Evaluation Using Strain Measurements. Journal of Bridge Engineering, 17(1), 130-138.
37.Liu, M., Frangopol, D. M., & Kim, S. (2009). Bridge Safety Evaluation Based on Monitored Live Load Effects. Journal of Bridge Engineering, 14(4), 257-269.
38.Frangopol, D. M., Strauss, A., & Kim, S. (2008). Bridge Reliability Assessment Based on Monitoring. Journal of Bridge Engineering, 13(3), 258-270.
39.Xu, Y. L., Zhang, X. H., Zhan, S., Hong, X. J., Zhu, L. D., Xia, Y., & Zhu, S. (2012). Testbed for Structural Health Monitoring of Long-Span Suspension Bridges. Journal of Bridge Engineering, 17(6), 896-906.
40.Jang, S., Li, J., & Spencer, B. F. (2013). Corrosion Estimation of a Historic Truss Bridge Using Model Updating. Journal of Bridge Engineering, 18(7), 678-689.
41.MIDAS civil 2010, MIDAS Information Technology Co., Ltd, http://www.midasuser.com.tw/index.aspx