PSI - Issue 84

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ScienceDirect

Procedia Structural Integrity 84 (2026) 749–756

© 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: Earth flow; viaduct and landslide; rainfall and landslide; infrastructure and landslide. This paper presents a singular case of an earthflow activated in highly tectonized clay shales of the red Flysch in Southern Italy. This earthflow is subject to continuous remobilizations in consequence of quite abundant rainfall, even if not always exceptional. The earthflow in its lower part is overtaken by a viaduct of an important national road. However, over time the toe of the earthflow had a regressive evolution and the active accumulation zone moved upward, filling the space between the intrados of the viaduct and the ground. Following the latest remobilizations, the clay shales of the earthflow have accumulated material on the upper side of the viaduct beams. Consequently, the beams drifted from the abutments due to the pushing effect of the ground accumulated upstream. Although the phenomenon does not yet compromise the viaduct’s functionality, it may cause a complete collapse of the viaduct if no interventions were implemented. This is an interesting case of direct interaction between landslides and viaducts. Interaction that involves not the foundations or abutments of the viaduct, but directly the beams of the viaduct itself. It highlights how in risk assessments related to the interaction between flows and viaducts it is necessary to pay close attention to the different morphological situations that may occur. Earth-flow landslides are widespread in all areas made up of flyschoid lithotype, as in the case of the orogenetic area of Southern Italian Apennine and they can have a significantly impact on infrastructures like roads, bridges, tunnels and viaducts. This type of landslide area is often characterized by intermittent movements, in which, phases of apparent stasis are followed by phases of significant activity, especially as consequence of particularly abundant rainfall. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications The impact of a slow active earth-flow on a viaduct of a national road in Southern Italy Antonio Fiorentino a , Lorenzo Di Taranto a *, Angelo Doglioni a , Vincenzo Simeone a a Department of Civil, Environmental and Architectural Engineering, Politecnico di Bari, Via Edoardo Orabona 4, Bari 70125, Italy Abstract

* Corresponding author. E-mail address: l.ditaranto@phd.poliba.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.2026.06.096