ABSTRACT
The use of the so-called direct approach, which simulates the complete dynamic soil–structure interaction, requires a lot of expertise that is far beyond the current engineering knowledge. Dynamic tests with environmental excitation are performed through identification techniques that do not require a knowledge of the input, the results can be continuously recorded, and it is possible to perform an unlimited number of tests without impairing the integrity of the structure, an aspect of paramount importance when dealing with built heritage. The analysis of the seismic response of the Ghirlandina tower, measured during the earthquake of 3 October 2012 proves the capability of the previously introduced spectral analysis to detect the dynamic parameters of the structure. Soil and masonry deformability both contribute to the dynamic response of the structure, so an optimization analysis was performed by considering both bending and axial modes.
