PSI - Issue 84

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 84 (2026) 1063–1070

© 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 The structural assessment of historical masonry tunnels represents a critical challenge for infrastructure managers, primarily due to significant uncertainties regarding original construction phases and material properties. Current safety guidelines require detailed quantitative verifications, yet standard numerical approaches often prove to be computationally prohibitive or unreliable without extensive datasets. To address this issue, this paper proposes a streamlined verification procedure based on a historical graphical method, suitably calibrated through in-situ diagnostic campaigns. The methodology was applied to the Giovi Tunnel (Italy), a representative case study characterized by heterogeneous masonry types and adaptive geometry. To validate the simplified approach, a comprehensive 2D non-linear Finite Element Model was developed, simulating the excavation process and adopting non-linear constitutive laws. The numerical results, benchmarked against in-situ flat-jack stress measurements, confirmed that the tunnel operates in a partially deconfined state (approx. 10% of the theoretical rock load). The comparative analysis demonstrates that the calibrated simplified method yields conservative stress estimates compared to the more rigorous FEM simulation. Consequently, the proposed workflow offers a reliable and efficient two-tiered framework for the safety assessment of large tunnel stocks, serving as a robust screening tool to prioritize deeper analyses. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Two-tiered approach for the structural assessment of old masonry tunnel linings Marialorenza Vescovi a , Gerardo Sorrentino b , Lapo Baccolini c , Manlio Culotta c , Stefano Gazzola c , Bernardino Chiaia b , Daniele Ferretti a , Erica Lenticchia b, * a University of Parma, Department of Engineering and Architecture, Parco Area delle Scienze, 181/A, Parma, 43124, Italy b Polytechnic University of Turin, Department of Structural, Geotechnical and Building Engineering (DISEG), Corso Duca degli Abruzzi 24, Torino, 10124, Italy c Tecne Gruppo Autostrade per l’Italia S.p.A., Viale Fulvio Testi 280, Milano, Italy)

* Corresponding author. Tel.: +39 0110904863. E-mail address: erica.lenticchia@polito.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.2026.06.136