PSI - Issue 84

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ScienceDirect

Procedia Structural Integrity 84 (2026) 1318–1325

© 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: post-tensioned bridges; tendon defectiveness; special inspections; imperfect detection; predicted information value. Abstract The estimation of the number of defective tendons in post-tensioned concrete bridges is a key input for the reliability assessment of prestressed girders. However, special inspection methods for detecting voids and assessing tendon condition are intrusive, time consuming, and costly, and the quantitative definition of an inspection sample size that meaningfully reduces epistemic uncertainty while keeping operational effort manageable is still rarely addressed in research and practice. This paper proposes a Value of Information approach, based on Bayesian methods to quantify and reduce uncertainty in tendon defectiveness by explicitly accounting for (i) the finite tendon population, (ii) prior information from past inspection campaigns, and (iii) imperfect detection through inspection sensitivity and specificity. The updated defectiveness model is coupled with a probabilistic flexural capacity assessment via Monte Carlo simulation and embedded in a Bayesian decision-theoretic formulation. The inspection sample size is selected by maximizing the predicted information value including inspection costs, balancing the expected reduction in decision risk (expected loss, including failure consequences) and the inspection effort. Results show a sharp increase in information value for small sample sizes followed by saturation, enabling identification of an optimal number of tendons to inspect and supporting cost-effective planning consistent with structural reliability requirements. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Value-of-Information-Based Inspection Planning for Post Tensioned Bridges Affected by Tendon Degradation Vittorio Palma a *, Simone Celati a , Agnese Natali a , Francesca Mattei a , Isabella Mazzatura a , Walter Salvatore a , Sebastian Thöns b a Dipartimento University of Pisa, Department of Civil and Industrial Engineering, Pisa Tuscany, Italy b Lund University, Division of Structural Engineering, Lund Skåne, Sweden

* Corresponding author. Tel.: 050 221 8240 E-mail address: vittorio.palma@phd.unipi.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.2026.06.168