PSI - Issue 78

Anna Brunetti et al. / Procedia Structural Integrity 78 (2026) 1729–1736

1736

5. Conclusions A study on the vibration serviceability assessment of a newly built steel arch footbridge in Central Italy (Marche Region) has been presented in this work. A numerical assessment of the effects induced by pedestrian loads is conducted according to the Sétra guidelines. Firstly, a detailed dynamic characterization of the structure was performed in order to calibrate the numerical model adopted in the bridge design, obtaining a reliable tool for investigating vibration serviceability issues. Then, steady state analyses were conducted for each critical frequency, which determined the maximum acceleration under resonance conditions. The bridge revealed to suffer of serviceability comfort issues since vertical accelerations exceed the mean comfort thresholds for the bridge class. Consequently, tuned mass dampers were designed in order to reduce vibrations under the pedestrian traffic; the design of the tuned mass dampers was performed by condensing the vertical dynamic problem of the bridge-tuned mass system into a 2-DOFs system, according to consolidated approaches available in the literature. The vibration serviceability analyses are finally carried out on the whole structure using the refined finite element model. Results of the numerical applications demonstrate a reduction in maximum accelerations by a factor of about four, compared to the initial acceleration, thus ensuring optimal comfort for users. Acknowledgements The authors would like to express their gratitude to Engineer Diego Coltrinari who has provided a valuable contribution to the development of the MATLAB script for the analyses. References Dall’Asta, A., Ragni, L., Zona, A., Nardini, L., Salvatore, W., 2016. Design and Experimental Analysis of an Externally Prestressed Steel and Concrete Footbridge Equipped with Vibration Mitigation Devices. Journal of Bridge Engineering, 21(8):C5015001. doi: 10.1061/(ASCE)BE.1943-5592.0000842. Den Hartog, J. P., 1985. Mechanical vibrations. Dover Publications, New York. Drygala, I.J., Polak, M.A., Dulinska, J.M, 2019. Vibration serviceability assessment of GFRP pedestrian bridges. Engineering Structures, 184, pp 176-185. doi: 10.1016/j.engstruct.2019.01.072. Ferreira, F., Simoes, L., 2019. Optimum design of a cable-stayed steel footbridge with three dimensional modelling and control devices. Engineering Structures, 180, pp 510 – 523. doi: 10.1016/j.engstruct.2018.11.038. Gong, M., Shen, R., Li, Y., Wang, H., Chen, W., & Wei, X., 2022. Practical Suggestions for Specifications for the Vibration Serviceability of Footbridges Based on Two Recent Long-Span Footbridges. Structural Engineering International, 33(4), 659 – 676. doi: 10.1080/10168664.2022.2149376. Li, J., Liu, X., 2023. Human-Induced Vibration Analysis and Reduction Design for Super Long Span Pedestrian Arch Bridges with Tuned Mass Dampers. Applied Sciences, 13(14), 8263. doi: 10.3390/app13148263. Nicoletti, V., Quarchioni, S., Tentella, L., Martini, R., Gara, F., 2023. Experimental Tests and Numerical Analyses for the Dynamic Characterization of a Steel and Wooden Cable-Stayed Footbridge. Infrastructures, 8(6), 100. doi: 10.3390/infrastructures8060100. Parloo, E., 2003. Application of Frequency-domain System Identification Techniques in the Field of Operational Modal Analysis, PhD Thesis, Vrije Universiteit Brussel. SÈTRA/AFGC, March 2006. Footbridges – Assessment of dynamic behaviour under the action of pedestrians. Guidelines, Sètra. Tophøj, L., Grathwol, N., Hansen, S. O., 2018. Effective Mass of Tuned Mass Dampers. Vibration, 1(1), 192-206. doi: 10.3390/vibration1010014. Van Nimmen, K., Van den Broeck, P., Verbeke, P., Schauvliege, C., Malliè, M., Ney, L., De Roeck, G., 2017. Numerical and experimental analysis of the vibration serviceability of the Bears’ Cage footbridge. Structure and Infrastructure Engineering, 13(3), pp. 390-400. doi: 10.1080/15732479.2016.1160133. Brincker, R., 2014. Some Elements of Operational Modal Analysis. Shock and Vibration, vol. 2014, no. 1, p. 325839. doi: 10.1155/2014/325839. Connor, J.J., 2003. Introduction to Structural Motion Control. Prentice Hall Pearson Education, Incorporated.