Steel-concrete composite bridges are an important alternative to concrete bridges due to considerable
advantages regarding the design, construction time, durability and costs. Therefore, they are largely used in highspeed lines of the European railway networks. The recently launched EC research project "DETAILS" aims to
remove actual uncertainties on dynamic effects and interaction phenomena, fatigue loadings, structural modelling,
fatigue life and damage assessment of these types of bridges. As part of the experimental work in the project, the Sesia Viaduct was extensively tested.
The viaduct is located on the new Italian high-speed line between Torino and Milano. Based on the results of an initial detailed vibration measurement campaign, a permanent monitoring system will be designed and installed. This paper focuses on this initial measurement campaign, involving the use of many accelerometer locations in order to obtain detailed mode shape information for correlation with and updating of Finite Element models. The paper discusses the acquired data under ambient and train excitation conditions and presents the Operational Modal Analysis results.
