Modeling of a cable-stayed pedestrian bridge using geometric and vibration data to update cable tensioning

The paper describes a procedure to determine cable re-tensioning and its effect in a cable-stayed pedestrian bridge, located in Beinasco, Italy. Different data acquisition systems were used to collect information about the as-built structure: terrestrial laser scanner to obtain a 3D geometrical model; uniaxial and triaxial accelerometers to record the vibration of the deck; accelerometers, and a highspeed camera to record the cable vibrations. Deck vibration data were used to identify its natural frequencies and mode shapes, cable vibration data were used to evaluate their natural frequencies and their axial forces. Geometric and vibration measurements permit to describe the cable-deck dynamics of the pedestrian bridge with high accuracy. The information was used to determine a reliable numerical model to simulate cable re-tensioning and its effect in the stayed structure of the walkway.