Dynamic Performance of Controlled Composite Structure of Footbridge

Resumo

Footbridges are structures subject to dynamic loads caused by a single or a varied number of pedestrians.
The dynamic interaction between pedestrians and the structure may bring discomfort to the users. Based on this,
the design of this type of footbridges require the evaluation of the behavior and the verification of the structure
strength under the combined action of static and dynamic loadings. This article presents a footbridge to be
constructed in composite steel-concrete structure considering only static loadings. Based on this, a dynamic
analysis of the footbridge was carried out to investigate the performance of the structure subjected to the
pedestrians traffic, considering two loading conditions, established by the Sètra guide: (i) a single pedestrian; (ii)
a crowd of pedestrians. Based on the maximum vertical accelerations, it was verified that the footbridge does not
attend the user comfort criteria to vertical vibration established by Sètra guide and ISO 10137 standard. Thus, it
has been made a parametric study to choose the features and design details of the passive attenuator of the TMD
type (Tuned Mass Damper) that is more appropriate. The results for the controlled footbridge show that the
structure meet the required comfort criteria.