Avaliação do conforto humano de passarelas de pedestres com base no desenvolvimento de uma metodologia de análise probabilística

Abstract

Currently, the pedestrian footbridges structural projects have become increasingly bold, modern, light and slender. However, slender pedestrian footbridges are more sensitive to dynamic excitations and may undergo changes in serviceability limit states related to excessive vibrations. Design standards and technical guides recommend the use of deterministic mathematical models to assess the footbridges dynamic structural behaviour. However, the human walking is a stochastic phenomenon and the dynamic force generated in each step depends on the weight, step frequency and step length of each individual. Therefore, this research work aims to contribute to the structural designers based on the development of an analysis methodology with a probabilistic approach for assessing the pedestrian footbridges dynamic behaviour, based on the generation of design response spectra, considering the stochastic nature of the human walking, aiming to analyse the structural response in relation to excessive vibrations that may cause human discomfort. This way, throughout the study, the dynamic structural behaviour of three existing pedestrian footbridges located at the city of Rio de Janeiro/RJ is investigated. Based on the use of the developed probabilistic analysis methodology, it becomes possible to determine the probability of the footbridge’s peak acceleration values exceeding or not the recommended criteria for human comfort assessment. The results obtained in this research work reveal that the peak accelerations determined using deterministic methods can be overestimated in design situations.