Structural identification via
modal analysis in structural mechanics is gaining popularity in
recent years, despite conceptual difficulties connected with its
use. This paper is devoted to illustrate advantages and also
indeterminacy characterizing structural identification problems
for bridge structures, even in rather simple instances. In
particular, an identification procedure based on modal analysis
and finite element model updating is presented for the
characterization of a concrete bridge which constructive typology
is quite diffuse in the area of Friuli Venezia Giulia (Italy).
Experience has suggested, so as to restrict the indeterminacy
frequently affecting identification issues, having resort to all
the a priori information on the system and mindfully selecting the
parameters to be identified. The analysis pointed out some
particularities of the modelling of the bridge typology under
study, otherwise not a priori detectable from the analytical
point of view.
