PSI - Issue 62

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Giuseppe Colombo et al. / Procedia Structural Integrity 62 (2024) 377–384 Colombo, Mariani, Lambrugo, Giardina/ Structural Integrity Procedia 00 (2023) 000 – 000

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Fig. 2. (a) longitudinal section of the buffer beam and the cantilevers; (b) cross sections.

1.2. The rehabilitation works of 1992 Towards the end of the 80s of the twentieth century, the carrying out of a series of checks on the work was entrusted to Prof. Ing. Francesco Martinez y Cabrera who performed a close inspection of the entire side of the deck and verified the resistance of the viaduct by applying the regulations in force at the time. The conclusions of the study were: • At the time of drafting the original project, the Italian regulations in force, regarding loads on road bridges, consisted of the circulars issued by the Ministry of Public Works no. 6018 of 9 June 1945 and no. 772 of 12 June 1946. These circulars did not provide for the presence of military loads as required from 1962 with circular no. 384. However, since the original calculation report was not available, it was not possible to determine the loads effectively considered by the designer. • From the static calculations carried out according to the Ministerial Decree of 2 August 1980, with reference to the shore spans and the outermost beams, the stress in the concrete of the span axes section was equal to 10 Mpa, therefore " high but acceptable ", while the maximum tension in the tensioned steel reached 230 Mpa, higher than that permissible for the steel used in 1959, similar to a FeB32K, which was 160 Mpa. In the areas of maximum shear, the shear sliding absorbed by the brackets was equal to only 35%, being therefore for the remaining part carried by the bent irons F = 40 mm, anchored, as mentioned, in an ineffective way and excessively concentrated. The rebars of the Gerber saddles were even stressed up to 250 Mpa, therefore far above the permissible limits.