Structural health status assessment of a cable-stayed bridge by means of experimental vibration analysis

The results of an experimental dynamic analysis and structural modelling of the Indiano Cable-Stayed Bridge in Florence, Italy, are presented in this paper. Ambient and traffic-induced vibration tests were first carried out. These allowed extracting the dynamic characteristics of the structure in terms of resonance frequencies, modal shapes and damping. The experimental results were used to set up a finite element model. The geometrical characteristics and the mechanical properties of the materials used in the structural design of the bridge were assumed. The model was then used to evaluate the effects of the static and seismic loads according to the present Italian Technical Code. The results pointed out the good performance of the bridge, even though it had been designed without accounting for the seismic actions.