PSI - Issue 62

Vincenzo Simeone et al. / Procedia Structural Integrity 62 (2024) 561–568 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Figure 5 A) The deformed bridge B) Geomorphological maps of the area (both after Guerricchio e Ronconi, 1997, mod.)

EGMS shows several PSs both on the bridge and in the surrounding area, with good coherence and well-defined trend. On the bridge there are two areas, one on the north abutment with a velocity of 4,9 mm/years consistent with the deformation observed on the bridge and with the result of the geomorphological survey (Fig. 6). The other on the middle of the bridge, that shows movements toward west and down with a velocity of 2,5 mm/year, also in this case consistent with the result of the geomorphological survey.

Figure 6 A) and B ) PSs in ascending and descending geometry C) Movement measured by PS

3.5 Lagonegro(PZ) railway bridge – Serra Viaduct One of the most famous nutcracker deformations of a bridge is surely the Lagonegro railway bridge, also known as Serra Viaduct or Student bridge. Il was built between 1916 and 1929, at the beginning of the age of reinforced concrete. It was inaugurated on October 1929 and immediately showed problems with the first pile rising of about 40 cm in less than 10 years. Deformations were so severe that the bridge was closed after 26 years. In fig. 7 there are pictures taken in 1990 and in 2020 showing the continuous deformation affecting the bridge. An interpretation of this phenomena was presented by Guerricchio and Melidoro (1981), as the consequence of the sliding of the large limestone block, on which Lagonegro town is located, on the Black Shale formation. It is an apparently stony flysch that has a plastic behavior with respect to limestone. On EGMS there are no PSs available on the bridge and in the surrounding area useful to give information on the