Identification of the modal properties of an instrumented building

Dynamical experimental tests for the structural identification of reinforced cyclopic concrete tower of the Provincial Administration building of Bari, Italy, have been performed for a long period in order to achieve a wide set of data. In this work new experimental data are shown and discussed. Different floors of the tower were simultaneously monitored in such a way to analyse the influence of the external excitation on the tower vibration amplitude. In particular, a very long acquisition (2 hours) during light fires explosions have been carried out Using the acceleration measurements, the modal parameters of the tower are identified consistently by two different output-only procedures: the first, based on the Enhanced Frequency Domain Decomposition, in the frequency domain; the second, based on the Stochastic Subspace Identification Method, works in the time domain. Considerations about the consistency of the results respect to the different methods and to the choice of the identification parameters are carried out.