GNGTS 2019 - Atti del 38° Convegno Nazionale

GNGTS 2019 S essione 3.2 679 Fig. 3 - Mode 1 (f = 3.36 Hz). (a) Finite element model; (b) Axonometric view; (c) Top view. for a rapid experimental dynamic characterization of the structure and of the investigated site. These results are useful to detect, at a preliminary phase, some critic situations, like a soil- structure resonance phenomenon. The investigated structure does not seems interested by soil-structure resonance phenomena, given the substantial difference between the resonance frequencies of the site and the ones of the tower. The experimental data allow a comparison with the numerical model of the bell tower. This comparison showed a correspondence in terms of resonance frequencies but have also stressed the need for more realistic considerations for the interaction of the tower with the church and for the modelling of the masonry. Indeed, the tower has undergone numerous restoration works over the years, so that more careful characterization of the masonry is necessary.