Resumen de Evaluating vibrations on a small-scale model of a timber footbridge
P.G.A. Segundinho, Antonio Alves Dias, Marcelo Rodrigo Carreira
In Brazil, the study of pedestrian-induced vibration on footbridges has been undertaken since theearly 1990s, for concrete and steel footbridges. However, there are no recorded studies of this kind fortimber footbridges. Brazilian code ABNT NBR 7190 (1997) gives design requirements only for staticloads in the case of timber footbridges, without considering the serviceability limit state from pedestrianinducedvibrations. The aim of this work is to perform a theoretical dynamic, numerical and experimentalanalysis on simply-supported timber footbridges, by using a small-scale model developed from a 24 mspan and 2 m width timber footbridge, with two main timber beams. Span and width were scaled down(1:4) to 6 m e 0.5 m, respectively. Among the conclusions reached herein, it is emphasized that theEuler-Bernoulli beam theory is suitable for calculating the vertical and lateral first natural frequenciesin simply-supported timber footbridges; however, special attention should be given to the evaluation oflateral bending stiffness, as it leads to conservative values.
