PSI - Issue 78

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 78 (2026) 734–744

© 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of XX ANIDIS Conference organizers Keywords: seismic isolation; isolators; sliding; Ciborium; church; seismic protection; seismic vulnerability; seismic risk; cultural heritage Abstract This work concerns the seismic isolation of one of the masterpieces of Renaissance sculpture in Umbria: the ciborium of the main altar in the Church of Santa Maria Maggiore in Spello, Italy. The intervention strategy was defined following a critical evaluation of the base isolation solution, supported by experimental tests aimed at the dynamic characterization of the sculpture. An in-depth understanding of the original construction techniques, materials, structural details, and their state of conservation was crucially important. The studies and analyses conducted revealed that seismic isolation is probably the only viable solution capable of both drastically reducing seismic risk and avoiding invasive interventions. In fact, by concentrating the intervention mainly at the foundation level—right beneath the monument itself—the sculpture remained unaffected by significant alterations. The execution of the work presented considerable challenges and was conducted with a “zero tolerance” policy for any even minimal movement or deformation of the sculptural group. Thanks to careful planning and the high level of technical expertise of the contractor, the desired result was successfully achieved: throughout all stages, no movement or deformation occurred in the ciborium or the altar. Both elements were kept in place during the excavation and construction of the isolation layer, with dismantling limited exclusively to the flooring. XX ANIDIS Conference Seismic base isolation of the ciborium of the high altar in the church of Santa Maria Maggiore in Spello, Italy Riccardo Vetturini a, *, Walter Cecchini a , Maria Gabriella Castellano b , Florian Castiglione c a INGENIUM srl, Corso Cavour 84, Foligno PG, Italy b FIP MEC srl, via Scapacchiò 41, Selvazzano Dentro PD, Italy c SABAP Umbria, Piazzetta della Sinagoga 2, Perugia PG, Italy

* Riccardo Vetturini. Tel.: +39.0742.350701. E-mail address: ing.vetturini@gmail.com

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of XX ANIDIS Conference organizers 10.1016/j.prostr.2025.12.094