Application of optimized spring-mass-damper pedestrian load models for vibration assessment of footbridges: numerical and experimental investigation of a cable-stayed system

This article explores the potential and accuracy of spring-mass-damper (SMD) pedestrian load modelling strategies for assessing human-induced vibrations of in-service footbridges. To this aim, a recent SMD modelling proposal based on uncoupled single-body measures (SMD-0, in the following) is specifically used for the calibration of key input parameters. Finite element numerical assumptions and findings are robustly supported by original experimental tests carried out on a case-study footbridge in Poland, proving that the proposed approach can serve as an effective tool for analysing vibrations in pedestrian systems. The research study, most importantly, integrates theoretical modelling with empirical and experimental validations, to enhance the credibility of the obtained results, as well as to support the general applicability of the presented methodology. Complex in-field tests are in fact conducted on the selected footbridge, aiming to assess the effects of pedestrians on its dynamic response. Numerical analyses, which are successively performed in ABAQUS/Standard, for a set of examined walking configurations, confirm the high sensitivity of the footbridge to resonance, which was also observed during the in-field tests. The presently used SMD-0 approach is further assessed towards past SMD literature proposals. As shown, the comparison of standard structural performance indicators (such as the peak acceleration value, root mean square and CREST factor) reveals a significant sensitivity of the footbridge response to the input parameters for the analyzed SMD models. Besides, the presently addressed SMD-0 model has the advantage of being based on single-body sensor measurements and its calibration is not affected by structural features. As such, potential applications of present findings could include the improvement of design standards and safety measures for similar structures.