Abstract
External post-tensioning tendons (EPTTs) are commonly used in concrete box girder bridges constructed using the balanced cantilever methods. Bridge managers and operators are increasingly interested in novel means of determining the health of these important structural components as traditional visual inspections provide little to no information on their state. Due to inferior grouting, corrosion of prestressing strands within some existing bridges have required replacement of EPTTs. Monitoring the structural vibration responses of EPTTs can provide a means to determine the remaining tension which provides crucial information on their state. The basic equations to determine the stress from the vibration responses are based on vibrating string theory. Many of the important parameters in the classical equations are difficult to precisely determine in the field (stiffness, length, support conditions, etc.) due to construction variability. The basic equations have been the foundation for the development of more complex equations that attempt to account for these variabilities. These theoretical equations have rarely been tested under uncontrolled conditions, such as for the evaluation of existing in-operation EPTTs. This paper will present the practical application of three theoretical equations presented in literature that have been developed for determining the tension in EPTTs. The equations make use of modal frequencies from eight different EPTTs of varying lengths in an existing concrete box girder bridge (the Confederation Bridge in eastern Canada). The aim of this study is to develop a testing methodology based on vibration monitoring that provides reliable results and that is more efficient than the static deflection technique currently used by bridge managers/operators. Results show that the monitoring of structural vibration responses is an efficient and reliable way of determining the tension in external post-tensioning tendons.
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References
Allemang RJ (2003) The modal assurance criterion—twenty years of use and abuse. SOUND Vib. 8
Chen C-C, Wu W-H, Leu M-R, Lai G (2016) Tension determination of stay cable or external tendon with complicated constraints using multiple vibration measurements. Measurement 86:182–195. https://doi.org/10.1016/j.measurement.2016.02.053
Cheung MS, Tadros GS, Brown T, Dilger WH et al (1997) Field monitoring and research on performance of the confederation bridge. Can J Civ Eng 24:951–962
Desjardins SL, Londoño NA, Lau DT, Khoo H (2006) Real-time data processing, analysis and visualization for structural monitoring of the confederation bridge. Adv Struct Eng 9:141–157. https://doi.org/10.1260/136943306776232864
Desjardins SL, Lau DT (2022) Advances in intelligent long-term vibration-based structural health-monitoring systems for bridges. Adv Struct Eng 15. https://doi.org/10.1177/13694332221081186
Dinh NDTT, Hung NH (2020) Evaluating the cable tension results by lift-off and vibration method in Viet Nam. IOP conference series materials science engineering, vol 869, p 052062. https://doi.org/10.1088/1757-899X/869/5/052062
Fang Z, Wang J (2012) Practical formula for cable tension estimation by vibration method. J Bridge Eng 17:161–164. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000200
Lee JK, Kang JW (2019) Experimental evaluation of vibration response of external post-tensioned tendons with corrosion. KSCE J Civ Eng 23:2561–2572. https://doi.org/10.1007/s12205-019-0735-5
Liu HB, Wang LL, Tan GJ, Cheng YC (2013) Effective prestressing force testing method of external prestressed bridge based on frequency method. Appl Mech Mater 303–306:363–366. https://doi.org/10.4028/www.scientific.net/AMM.303-306.363
Stevenson J, McGinn DJ (2018) External post-tensioning evaluation after 20 years. In: IABSE conference 2018. Presented at the engineering the past, to meet the needs of the future, Copenhagen, Denmark, p 7
Wen-Hwa W, Chien-Chou C, Gwolong L, Min-Ray L (2012) Determination of stay cable force based on multiple vibration measurements to consider the effects of unsymmetrical boundary constraints. 6th Eur. Workshop Struct. Health Monit. EWSHM 2012 8
Wu W-H, Chen C-C, Chen Y-C, Lai G, Huang C-M (2018) Tension determination for suspenders of arch bridge based on multiple vibration measurements concentrated at one end. Measurement 123:254–269. https://doi.org/10.1016/j.measurement.2018.03.077
Yan B, Li D, Chen W, Deng L, Jiang X (2020) Mode shape–aided cable force determination using digital image correlation. Struct Health Monit 16. https://doi.org/10.1177/1475921720952163
Yu C-P (2020) Tension prediction for straight cables based on effective vibration length with a two-frequency approach. Eng Struct 222:13. https://doi.org/10.1016/j.engstruct.2020.111121
Acknowledgements
The authors would like to acknowledge the contributions from Strait Crossing Bridge Limited in providing access to the Confederation Bridge to develop this test, and for the equipment and documentation provided to support the study.
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© 2023 Canadian Society for Civil Engineering
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Pellerin, E., Desjardins, S., McGinn, D. (2023). External Post Tensioning Evaluation Using Vibration Response Measurements. In: Gupta, R., et al. Proceedings of the Canadian Society of Civil Engineering Annual Conference 2022. CSCE 2022. Lecture Notes in Civil Engineering, vol 348. Springer, Cham. https://doi.org/10.1007/978-3-031-34159-5_63
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DOI: https://doi.org/10.1007/978-3-031-34159-5_63
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