PSI - Issue 84

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ScienceDirect

Procedia Structural Integrity 84 (2026) 591–598

© 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 present paper deals with the numerical modelling and calibration of the “Ponte delle Grazie”, a concrete Gerber-type bridge located in Faenza (Italy) spanning the Lamone River. The bridge has a total length of 72 meters, a width of 13 meters, and consists of three spans, including a suspended deck segment supported by Gerber saddles. Built in 1950, the bridge was found to be in critical condition during 2017 inspections, with significant damage to the rocker bearings, Gerber saddles, and lateral girders, leading to urgent repairs. A follow-up evaluation according to Italian guidelines confirmed serious structural issues, prompting additional repairs in 2024. Consequently, a permanent monitoring system was installed that year as part of the DIGI-BRIDGE research project . To support an in-depth evaluation of the structural behavior, a finite element model of the superstructure has been developed based on the available design documents and a laser scanner survey. The model is calibrated against the modal properties identified through ambient vibration testing to ensure the numerical predictions closely match the experimental results. The calibration procedure is performed adopting an improved surrogate-assisted evolutionary algorithm, which combines the robustness of the Differential Evolution algorithm with the computational efficiency of a second-order surrogate approximation and of an effective infill sampling strategy. Results confirm the effectiveness of the calibration strategy in producing a numerical model that accurately represents the bridge actual dynamic behavior and serves as a valuable tool for further structural assessment. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Dynamic identification and finite element model calibration of a Gerber-type bridge Laura Dieci a , Giorgia Ghirelli a , Daniele Scocciolini b , Federico Ponsi a , Ghita Eslami Varzaneh a , Elisa Bassoli a * , Nicola Buratti b Loris Vincenzi a a Department of Engineering “Enzo Ferrari”, Via P. Vivarelli 10, Modena 41125, Italy , Bologna 40126, Italy

Peer-review under responsibility of the scientific committee of the Conference Keywords: Bridge monitoring; Gerber-type bridge; Finite Element model calibration

* Corresponding author. Tel.: +39-059-205-6213 E-mail address: elisa.bassoli@unimore.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.2026.06.076