PSI - Issue 84

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ScienceDirect

Procedia Structural Integrity 84 (2026) 931–936

© 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) Abstract The San Donnino viaduct in upper Garfagnana is a prestressed concrete box structure with a static scheme characterized by a large central span and two small lateral ones with significant lifting reactions. Following the breakage of the constraint cables, the viaduct was the subject of attention to the point of its demolition. The replacement of the constraint cables has restored the initial situation which was followed by monitoring of the structure. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Repair of San Donnino viaduct M. Viviani a ,P. Saletti b, *, A. Gioeli b , R. Mencarini b , M. Silvestri b , R. Guidi b a Maffeis Engineering Spa (VI), Italy b Provincia di Lucca, Italy 1. Introduction Repair of San Donnino viaduct, in upper Garfagnana (LU, Italy), is an example of fixing of a prestressed concrete structure, carried out thanks to the original static scheme and the analysis of technology that have been used at the time of construction. In June 2022 the viaduct abutments towards Piazza al Serchio suddenly lift in his joint, so the transit was impossible. Lucca Province’s administration closed immediately the viaduct and commissioned an engineering company to study the actions to be taken. After a first phase consisting in the positioning of concrete block counterweights, which proved insufficient to ensure safety, projects and hypothesis were drawn up [1]. These involved either a lengthy closure period or, Peer-review under responsibility of the scientific committee of the Conference Keywords: existing structure repair; lifting reaction; prestressed concrete viaduct.

* Corresponding author. E-mail address: pierluigi.saletti@provincia.lucca.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 10.1016/j.prostr.2026.06.119