Dynamic Tests on a Large Cable-Stayed Bridge

Abstract

This paper describes the dynamic tests performed on a large cable-stayed bridge, Vasco da Gama Bridge, on the basis of a non-conventional testing system, comprehending several independent accelerographs conveniently synchronised by a laptop, as well as a laser interferometry system for non-contact dynamic measurements in stay cables. This system showed to be rather portable, efficient and accurate, leading to the creation of a very large high quality data base concerning the dynamic behaviour of the bridge. Subsequent processing of the data permitted to identify accurately all the significant modal parameters of interest from the aerodynamic and seismic point of view, which present a very good correlation with the corresponding values provided by the 3-D numerical finite element model previously developed at the design stage