한국구조물진단유지관리공학회 논문집 (Journal of the Korea institute for structural maintenance and inspection)

  • 제26권4호
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  • Pages.20-29
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  • 2022
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  • 2234-6937(pISSN)
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  • 2287-6979(eISSN)
한국구조물진단유지관리공학회 (Korea Institute for Structural Maintenance Inspection)
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운용모드해석에 기반한 사장교의 장단기 동특성 평가

Evaluation of Short and Long-Term Modal Parameters of a Cable-Stayed Bridge Based on Operational Modal Analysis

  • 박종칠 (한국도로공사 도로교통연구원)
  • 투고 : 2022.06.07
  • 심사 : 2022.07.15
  • 발행 : 2022.08.30
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초록

상시진동을 이용하여 구조계의 동특성을 추출하는 운용모드해석 기법은 케이블교량 구조건전성모니터링의 한 분야로써 다양한 연구와 실험적 검증이 수행되어왔다. 본 연구에서는 두 번에 걸친 상시진동실험과 함께 3년간의 장기 계측을 통해 수집된 가속도 데이터를 이용하여 공용 중인 사장교의 장단기 동특성을 평가하였다. 교량 준공 이후 6년과 19년이 경과한 시기에 실시한 고해상도 상시진동실험으로부터 0.1 ~ 2.5 Hz 대역에서 27개 수직모드(휨, 비틈)와 1개 수평모드를 추출하였다. 운용모드해석에 기반한 동특성 추출은 PP기법, ERADC기법, FDD기법, TDD기법을 적용하였으며, 적용한 기법들 간에 유의미한 차이가 없는 것을 확인하였다. 장기 계측 고유진동수와 환경 요인(온도, 바람)에 대한 상관성 분석으로부터 온도 변화가 고유진동수 변동에 지배적인 영향인자임을 확인하였다. 대상교량의 고유진동수 감소 경향은 구조성능과 일체성이 변한 것이 아니라 두 번의 상시진동실험 간 온도 차이에 의한 환경영향이 컸음을 밝혔다. 또한 TDD기법 적용 시, 지연이 0에서 자기상관이 1이 되도록 시퀀스를 정규화하는 알고리즘을 추가하여 모드형상 추출의 정확도를 개선하였다.

The operational modal analysis (OMA) technique, which extracts the modal parameters of a structural system using ambient vibrations, has been actively developed as a field of structural health monitoring of cable-supported bridges. In this paper, the short and long-term modal parameters of a cable-stayed bridge were evaluated using the acceleration data obtained from the two ambient vibration tests (AVTs) and three years of continuous measurements. A total of 27 vertical modes and 1 lateral mode in the range 0.1 ~ 2.5 Hz were extracted from the high-resolution AVTs which were conducted in the 6th and 19th years after its completion. Existing OMA methods such as Peak-Picking (PP), Eigensystem Realization Algorithm with Data Correlation (ERADC), Frequency Domain Decomposition (FDD) and Time Domain Decomposition (TDD) were applied for modal parameters extraction, and it was confirmed that there was no significant difference between the applied methods. From the correlation analysis between long-term natural frequencies and environmental factors, it was confirmed that temperature change is the dominant factor influencing natural frequency fluctuations. It was revealed that the decreased natural frequencies of the bridge were not due to changes in structural performance and integrity, but to the environmental effects caused by the temperature difference between the two AVTs. In addition, when the TDD technique is applied, the accuracy of extracted mode shapes is improved by adding a proposed algorithm that normalizes the sequence so that the autocorrelations at zero lag equal 1.

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참고문헌

  1. Cho, S., Jo, H., Jang, S., Park, J., Jung, H. J., Yun, C. B., Spencer, B. F., and Seo, J. W. (2010), Structural Health Monitoring of a Cable-Stayed Bridge Using Wireless Smart Sensor Technology: Data Analysis, Smart Structures and Systems, 6(5-6), 461-480. https://doi.org/10.12989/SSS.2010.6.5_6.461
  2. Conte, J. P., He, X., Moaveni, B., and Masri, S. F. (2008), Dynamic Testing of Alfred Zampa Memorial Bridge, Journal of Structural Engineering, ASCE, 134(6), 1006-1015. https://doi.org/10.1061/(ASCE)0733-9445(2008)134:6(1006)
  3. Cross, E. J., Koo, K. Y., Brownjohn, J. M. W., and Worden, K. (2013), Long-Term Monitoring and Data Analysis of the Tamar Bridge, Mechanical Systems and Signal Processing, 35(1-2), 16-34. https://doi.org/10.1016/j.ymssp.2012.08.026
  4. Cunha, A., Caetano, E., Magalhaes, F., and Moutinho, C. (2013), Recent Perspectives in Dynamic Testing and Monitoring of Bridges, Structural Control and Heath Monitoring, 20(6), 853-877. https://doi.org/10.1002/stc.1516
  5. Cunha, A., Caetano, E., Magalhaes, F., Moutinho, C., and Pereira, S. (2021), Dynamic Testing and Continuous Dynamic Monitoring of Transportation, Stadia and Energy Infrastructures, International Workshop on Civil Structural Health Monitoring, CSHM 2021, 156, 15-55.
  6. Ding, Y. L., Li, A. Q., and Geng, F. F. (2010), Variability of Measured Modal Frequencies of a Suspension Bridge under Actual Environmental Effects, Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management, IABMAS, 1380-1387.
  7. Han, Q., Ma, Q., Xu, J., and Liu, M. (2021), Structural Health Monitoring Research under Varying Temperature Condition: a Review, Journal of Civil Structural Health Monitoring, 11, 149-173. https://doi.org/10.1007/s13349-020-00444-x
  8. Hernandez, W., Viviescas, A., and Riveros-Jerez, C. A. (2022), Water-Structure Interaction Analysis of a Segmental Bridge Using Ambient Vibration Testing at Different Water Levels, Proceedings of the 1st Conference of the European Association on Quality Control of Bridges and Structures, EUROSTRUCT 2021, Padua, Italy, 200, 1226-1233.
  9. Hong, D. S. and Kim, J. T. (2010), Structural Health Monitoring of Full-Scale Concrete Girder Bridge Using Acceleration Response, Journal of the Korea Institute for Structural Maintenance and Inspection, KSMI, 14(1), 165-174 (in Korean). https://doi.org/10.11112/JKSMI.2010.14.1.165
  10. Jung, D. S., Kim, C. Y., Kim, N. S., and Yoon, J. G. (2002), Estimation of Dynamic Characteristics of Namhae Suspension Bridge Using Ambient Vibration Test, Journal of the Korean Society of Civil Engineers, KSCE, 22(6A), 1501-1514 (in Korean).
  11. Kim, B. H., Park, M. S., and Lee, I. K. (2008), Modal Parameter Extraction of Seohae Cable-Stayed Bridge: I. Mode Shape, Journal of the Korean Society of Civil Engineers, KSCE, 28(5A), 631-639 (in Korean).
  12. Kim, B. H., Park, T., and Stubbs, N. (2005), A New Method to Extract Modal Parameters Using Output-Only Responses, Journal of Sound and Vibration, 282(1-2), 215-230. https://doi.org/10.1016/j.jsv.2004.02.026
  13. McDonald, S. (2016), Operational Modal Analysis, Model Updating, and Seismic Analysis of a Cable-Stayed Bridge, Master's Thesis, The University of British Columbia, Vancouver, Canada.
  14. Magalhaes, F., Caetano, E., Cunha, A, Flamand, O., and Grillaud, G. (2012), Ambient and Free Vibration Tests of the Millau Viaduct: Evaluation of Alternative Processing Strategies, Engineering Structures, 45, 372-384. https://doi.org/10.1016/j.engstruct.2012.06.038
  15. Magalhaes, F., Cunha, A., and Caetano, E. (2014), Five Years of Continuous Dynamic Monitoring of Infante D. Henrique Bridge, Proceedings of the 9th International Conference on Structural Dynamics, EURODYN 2014, Porto, Portugal, 2263-2270.
  16. Park, J. C., Gil, H. B., Kang, S. G., and Lim, C. W. (2010), Dynamic Characteristics of a Cable-Stayed Bridge Using Global Navigation Satellite System, Journal of the Korean Society of Civil Engineers, KSCE, 30(4A), 375-382 (in Korean).
  17. Park, W., Kim, H. K,, and Park, J. (2012), Finite Element Model Updating for a Cable-Stayed Bridge Using Manual Tuning and Sensitivity-Based Optimization, Structural Engineering International, 22(1), 14-19. https://doi.org/10.2749/101686612X13216060212870
  18. Rainieri, C. and Fabbrocino, G. (2014), Operational Modal Analysis of Civil Engineering Structures, Springer, New York, 1-210.
  19. Wang, H., Mao, J. X., and Xu, Z. D. (2020), Investigation of Dynamic Properties of a Long-Span Cable-Stayed Bridge During Typhoon Events Based on Structural Health Monitoring, Journal of Wind Engineering and Industrial Aerodynamics, 201, 104172. https://doi.org/10.1016/j.jweia.2020.104172
  20. Westgate, R. J. (2012), Environmental Effects on a Suspension Bridges's Performance, Ph.D. Dissertation, The University of Sheffield, Sheffield, UK.