PSI - Issue 62

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

565

5

Figure 3 A) Repaired fissure in the keystone of the arch B) Circular and square dots refer respectively to PSs in ascending and descending geometry C) The slope gravitative deformation affecting the first arch on the right side of the valley

3.3 Mansory arch bridge on Grassano Irsina SP209 provincial road Also this ridge is located in the Bradanic trough where it Sub-Appenine clays outcrop, as in the previous case and the bridge cross a valley with really steep flanks. The arch is clearly subject to a nutcracker deformation (Fig. 4A). For this bridge there are no PS available close to the bridge abutments. Anyway on the right side of the valley there is a farm where, using the interferometric analysis of EGMS, it was identified a movement toward the valley with a velocity of 2.3 mm/years, consistent with the deformations observed on the bridge (Fig. 4B).

Figure 4 A) The deformed masonry arch bridge B) Movement measured by PS on the slope upward the right side of the abutment.

3.4 The masonry twelve arch former railway bridge between Paola and Cosenza Another interesting case of nutcracker deformation is that of the twelve-arches former railway bridge between Paola and Cosenza in Calabria. The bridge was built in masonry, 200 m long and 5 m large, with 12 arches, oriented along north-south direction. The north abutment shows horizontal deep fissures and cracks on the keystone of the first arch, whit an uplift of the above correspondent border. The area where the bridge was built is complex and interested by severe deep seated landslide deformations. The geology and the geomorphology of the area was detailed by Guericchio and Ronconi (1997), who identified in this area an ancient deep seated slope gravitational deformation, 2-3 km large, with E-W movement, toward the coast line, reactivated by the 1783 earthquake. The bridge is built to cross a depression of the higher scarp at 550 m asl; on the slope above the bridge there are further evident signs of landslide movement. Eluvial deposits cover the depression. All over there are lightly cemented conglomerates, with local sandy intercalation from the Upper Pleistocene containing blocks of sandstones and brownish sands with conglomerate lenses, from Middle-Upper Miocene and limestones and whitish and greyish calcarenites, from the Middle-Upper Miocene. The first arch is strongly compressed even several iron beams have been used to limit the compression due to slope gravitational deformations (Fig 5).