Dynamic Response of Marzocco by Donatello to Seismic Excitation

The protection of masterpieces from natural hazards is one of the most important goals regarding heritage conservation. This work studies the seismic response of “Marzocco” by Donatello, which is the heraldic symbol of Florence, currently exposed at the National Museum of Bargello (Florence, Italy). The sculpture stands over a marble base and a magnificent marble pedestal by Benedetto da Maiano, which is part of the piece of art. The artwork is placed on the first floor of the museum, and it is subjected to seismic accelerations, eventually amplified by the seismic response of the building itself. The dynamic response of Marzocco is checked with reference to the overturning and sliding collapse mechanisms. Three overturning models have been considered, involving respectively the statue only, the statue and the base, and the statue with base and pedestal. The seismic input has been assumed through an ensemble of seven ground motions, which is spectrum-compatible with the Code’s one. Both the acceleration histories at the ground and at the floor have been considered. The seismic response has been found by performing a time-history analysis on a finite element model. The analysis showed a satisfactory seismic performance of the case study, pointing out the role of the single modeling assumptions.