PSI - Issue 84

Antonio Fiorentino et al. / Procedia Structural Integrity 84 (2026) 749–756

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Fig. 3 – (a) Evidence of the viaduct deck translation relative to its bearing plane. (b) Direct impact of the earthflow, with debris accumulation against the viaduct deck. (c) Evidence of the viaduct deck displacements

In Fig. 4 is highlights the phenomenon using a comparison between the 2014 LIDAR survey developed by the Basilicata Region and the LIDAR survey carried out by the authors (august 2024) as part of this study. It is clearly visible that only the portion of the flow upstream of the viaduct, which blocked the flow itself, has been reactivated. In fact, in the longitudinal cross section of the earthflow (Fig. 4a) the surveys coincide perfectly in the section downstream of the viaduct, while upstream of the viaduct the accumulation of the latest remobilizations can be observed. Two transects of the earthflow (Figs 4b and 4c) upstream and downstream of the viaduct were used to compare the LIDAR surveys of 2014 and those of 2024. The section downstream of the viaduct is almost unchanged, demonstrating that there was no flow of material under the viaduct, while on the other hand it is visible that upstream a large accumulation has developed on the right flank of the flow, which is what pushed the viaduct beams, resulting in the displacement detectable on the surface.