PSI - Issue 78

Riccardo Vetturini et al. / Procedia Structural Integrity 78 (2026) 734–744

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1. Generalities Seismic isolation is now a well-established seismic protection technique that has progressively spread, initially to bridges and viaducts, then to new buildings and more recently to existing ones. Its use for protecting artistic heritage has been sporadic until now, although interventions on individual works of art are continuously increasing. Some examples include Bronzes of Riace, the Bust of Francesco I d’Este sculpted by Gian Lorenzo Bernini, statue of San Michele Arcangelo by Matteo di Ugolino, Pietà Rodanini by Michelangelo Buonarroti, the pinnacles of the Prospettiva in Corso Giovecca in Ferrara, the columns of the Forum of Peace in Rome, and some works of art displayed in the National Museum of Abruzzo in L’Aquila and in the National Roman Museum at the Baths of Diocletian ( Research Report “Safety of Cultural Heritage” - Fondazione Scuola Beni Attività Culturali ). The present intervention on the Ciborium of the High Altar of the Church of Santa Maggiore in Spello stands out in this context; its main peculiarities and unique features will be highlighted in the following. 2. Description The Ciborium of the high altar in the Church of Santa Maria Maggiore in Spello, conceived by Rocco di Tommaso da Vicenza in the early 1500s, is considered one of the “masterpieces of Renaissance sculpture in Umbria.” Built entirely in caciolfa stone (Focaoaru et al., 1994), the construction rests on four finely decorated quadrangular pedestals, from which rise four Corinthian-style columns, also richly decorated with friezes and ornaments. These columns support a hemispherical dome through four elegant circular arches, anchored by a tie-rod system at the springing, consisting of rectangular-section iron bars presumably dating back to the construction phase, as well as a recently installed temporary system of additional tie rods, consisting of two thin-section steel cables placed alongside each iron bar.

Fig. 1. Section along the diagonal of the Ciborium and hypothesized construction section