The paper shows the different dynamic tests performed in two-cable-stayed bridges: the Alamillo in Spain and the General Belgrano (Chaco-Corrientes) in Argentina The first is a newly constructed bridge and the dynamic tests performed just after completion of the construction were justified to update the mathematical and scaled models used in the wind tunnel tests. The second corresponds to an existing cable-stayed bridge where a repair and strengthening work had to be undertaken. In this case, the model updating and correlation was mandatory to know some of the mst important parameters involved in the design of the most effective repair (deck properties, cable forces,...). It is shown how with a minimum instrumentation and recording set-up, and with very simple excitation techniques, it is possible to perform reliable and helpful dynamic field tests.
