PSI - Issue 84

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ScienceDirect

Procedia Structural Integrity 84 (2026) 805–812

© 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 identification and monitoring of landslide, as well as the estimation of key parameters remain complex tasks in landslide in the risk assessment of critical infrastructure, particularly bridges. These challenges are magnified during rapid field surveys, when time constraints and limited data availability can affect the completeness and reliability of the collected data. Conceptual and procedural biases within the LLG 2020 makes these difficulties even greater and contribute to compromising the assessment of the Landslide Class of Attention (CdA) for bridges. This study examines ambiguities in key terms and their influence on the reliability of the CdA assessment, and proposes a coherent, literature-grounded clarification that resolves these ambiguities and enhances the reliability and the robustness, consistency, and effectiveness of CdA evaluation. Based on five years of periodic inspections of landslides affecting or threatening bridges—under the LLG 2020—the main ambiguities concern: (i) the distinction between, Susceptibility, Susceptibility Class and Factor of Susceptibility ; (ii) the use of the term potential landslide and its undefined related primary parameter criticality level ; and (iii) inconsistencies in two secondary parameters. In alignment with LLG 2020, the study proposes: (a) the adoption of Slope Instability Degree in place of Slope Instability and Slope Instability Class in place of Susceptibility Class ; (b) the redefinition of the secondary parameters Reliability of primary parameter estimation and Status of mitigation works ; and (c) the elimination of the term potential landslide and its related parameter. This work also clarifies the distinction between Susceptibility and Factor of Susceptibility , demonstrating improved logical coherence, operational clarity, and enhanced robustness and reproducibility of CdA assessment. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Enhancing Landslide Class of Attention Assessment in the Italian LLG 2020 Nicola Perilli a *, Nunziante Squeglia a , Stefano Stacul a , Angelo Doglioni b , Vincenzo Simeone b a Department of Civil and Industrial Engineering, University of Pisa, Largo L. Lazzarino 1, Pisa 56122, Italy b Department of Civil, Environmental and Architectural Engineering, Politecnico di Bari, Via Edoardo Orabona 4, Bari 70125, Italy

* Corresponding author. E-mail address: nicola.perilli@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.2026.06.103