PSI - Issue 84

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2026) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 84 (2026) 25–32

III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Application of seismic isolation in the retrofit of bridges in Italy Federico Scafati a *, Chiara Ormando b , Paolo Clemente c , Giacomo Buffarini b

a University of L’Aquila, Piazzale Ernesto Pontieri, 67100 L’Aquila, Italy b ENEA Casaccia Research Centre, Via Anguillarese 301, 00123 Rome, Italy c Formerly ENEA Casaccia Research Centre, Via Anguillarese 301, 00123 Rome, Italy

© 2026 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 the scientific committee of the Conference Abstract Seismic isolation is a suitable and consolidated technique to protect bridges against earthquakes, allowing to achieve a level of safety not possible with traditional systems. Seismic retrofitting can often be obtained by just replacing existing bearings with anti seismic devices. In some cases, retrofitting of the vertical structures, piers, and abutments is also necessary, while deck replacement is often linked to concrete deterioration and the need to upgrade the roadway to new standards. This paper traces the development of seismic isolation in Italian bridges alongside the evolution of seismic hazard classification. Furthermore, it describes three bridges that represent typical cases in which isolation devices are installed in place of existing bearings. In the first case study high damping rubber bearings were inserted to seismically isolate a simple reinforced concrete deck. Contemporarily, a kinematic chain is realized between supported girders to improve the response to horizontal loads but keeping the static scheme unchanged for vertical loads. In the second one, double curved surface sliders were used for prestressed reinforced concrete girders and shock transmitters were introduced between adjacent spans in correspondence of the piers to connect them in seismic conditions. In the third example, new lead rubber bearings support a new continuous mixed steel-concrete deck. All bridges belong to the Italian highway network and are in high seismic areas characterized by significant peak ground accelerations. The interventions allow the structures to be conformed to current Italian standards. These are just a few examples to serve as a guide for future applications. © 2026 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 the scientific committee of the Conference

Keywords: Seismic isolation, Energy dissipation, Bridges, Seismic retrofit.

* Corresponding author. E-mail address: federico.scafati@guest.univaq.it

2452-3216 © 2026 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 the scientific committee of the Conference

2452-3216 © 2026 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 the scientific committee of the Conference 10.1016/j.prostr.2026.06.004