Human-induced vibrations of a curved cable-stayed footbridge

This paper investigates and compares the performances of two simulation models to predict the footbridge response to vertical pedestrian dynamic actions. For this purpose, a rational procedure based on experimental tests, identification, model-updating and simulation is addressed. The object of study is the Pasternak footbridge, a curved cable-stayed footbridge prone to human-induced vibrations. The footbridge dynamic behaviour is investigated thanks to an experimental campaign. Accelerations due to ambient vibrations are recorded and the modal parameters of the structure are identified. The dynamic response to pedestrian actions is investigated performing several experimental tests with different-sized groups of pedestrians. To simulate the dynamic response to pedestrian actions, a Finite Element (FE) model of the footbridge is developed and calibrated so that the numerical dynamic properties match the experimental ones. The structural response to human loads is evaluated through two advanced simulation methods. The first one is based on a periodic walking force and is employed to perform dynamic analyses with the FE model. In the second one, a multi-harmonic force model, which considers the variability of the walking force, is adopted and the dynamic response is evaluated via modal decomposition. Finally, numerical and experimental results are compared with each other.