PSI - Issue 44

Riccardo Martini et al. / Procedia Structural Integrity 44 (2023) 657–664 Riccardo Martini et al. / Structu al Integrity Procedia 00 (2022) 00–000

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Fig. 5. Frequency contents of the experimental results (a) and FE models (b).

4. Conclusions The dynamic tests on bridges, during the static load proof tests, can be affected by bridge-interaction phenomena that may lead some misinterpretations of the tests. In this paper, the bridge-truck interaction phenomena are investigated from both an analytical and experimental point of view. Firstly, a simple 2-DoF system is used to analyze the phenomena for the most common load test configurations and bridge types, and a graphical tool to estimate bridge-truck interaction phenomena is presented. In details, the graph allows a preliminary assessment of the intensity of the bridge-truck interaction phenomena (for a specific type of bridge and load configuration) and, in addition, an estimation of the expected frequencies of the first bending vibration mode of the loaded bridge (during the static proof load test), supporting the interpretation of the dynamic tests. Finally, an investigation of the BTI phenomena on a real case study, during the static proof load test, is presented and analyzed. The experimental results are compared with the analytical ones obtained from two FE models and the significance of the bridge-truck interaction is addressed for the case at hand. As result of the investigation, the proposed graph is shown to be an effective tool to preliminarily assess the influence of the BTI phenomena and it can be used to evaluate the expected bending mode frequencies of the loaded bridge with a reasonable degree of approximation. References Mitoulis, S. A., Domaneschi, M., Cimellaro, G. P., Casas, J. R., 2021. Bridge and transport network resilience – a perspective. Proceedings of the Institution of Civil Engineers - Bridge Engineering, 1–12. https://doi.org/10.1680/jbren.21.00055 AASHTO, 2018. The Manual for Bridge Evaluation. American Association of State Highway and Transportation Officials and Subcommittee on Bridges and Structures. SIA, 2011. Existing structures - Bases. SIA 505 269:2011, SIA Schweizerischer Ingenieur und Architecktenverein. Zurich. D.M.17.01.2018, Aggiornamento delle « Norme Tecniche per le Costruzioni » , Ministero delle Infrastrutture e dei Trasporti, G.U. n.42, 20.02.2018. Ribeiro, D., Calçada, R., Brehm, M., Zabel, V., 2021. Calibration of the Numerical Model of a Track Section over a Railway Bridge Based on Dynamic Tests. Structures 34 (December 2021): 4124–4141. https://doi.org/10.1016/j.istruc.2021.09.109. Cachot, E., Vayssade, T.; Virlogeux, M.; Lancon, H.; Hajar, Z.; Servant, C., 2015. The Millau Viaduct: Ten years of structural monitoring. Struct. Eng. Int. 2015, 25, 375–380. https://doi.org/10.2749/101686615X14355644770776. Innocenzi, R. D., Nicoletti, V., Arezzo, D., Carbonari, S., Gara, F., Dezi, L., 2022. A Good Practice for the Proof Testing of Cable-Stayed Bridges. Applied Sciences 12, no. 7 (March 31, 2022): 3547. Accessed June 22, 2022. https://www.mdpi.com/2076-3417/12/7/3547. Chen, G.-W., Omenzetter, P., Beskhyroun, S., 2022. Modal Systems Identification of an Eleven-Span Concrete Motorway off-Ramp Bridge Using Various Excitations. Engineering Structures 229 (February 2021): 111604. https://doi.org/10.1016/j.engstruct.2020.111604.