Condition assessment and dynamic system identification of a historic suspension footbridge

The Morca footbridge is a historic suspension bridge, originally constructed in 1928. The bridge is characterized by the timber deck supported by two pairs of cables that were recently replaced. After the strengthening, an extensive program of non-destructive global tests was carried out; the field tests included complete geometric survey of the deformed configuration due to dead loads, static load tests and ambient vibration measurements. The experimental investigation was complemented by the development of a 3D finite element model and the correlation between theoretical and experimental results suggested a satisfactory state of preservation of the deck timber elements but also the potential weakness of some nodes. Hence, the dynamic tests were repeated in order to evaluate any changes in the modal parameters and the correlation with structural modifications or damage.