PSI - Issue 62

381 5

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

Fig. 4. Determination of global attention class based on “Bridge Guidelines”

2. Rehabilitation works of 2023 2.1. Prestressing

The investigations carried out on the structure in question have shown a state of execution and conservation of the structural reinforcement interventions carried out in the 90s far from the project indications, more precisely: • numerous prestressing cables were found to be completely ineffective due to the breakage of the strands (or their failure to install) or at an extremely low level of tension in them and in any case significantly lower than that assumed at final time in the verifications of the original project of the intervention. • The cable anchoring systems were connected to the structure through a system of prestressing bars that have not been tensioned and that in almost all cases were made in a way that differs from the project: the connection system had bars embedded directly in the cast of the blocks, therefore not stretchable and often without a complete anchoring system in the terminal sections (contrast plate, nut and protection bell). • The entire pre-stressing and anchoring system was only protected with inadequate and inadequately injected or sufficiently protected sheaths.