PSI - Issue 62

88 Alberto Contardi et al. / Procedia Structural Integrity 62 (2024) 81–88 Contardi A., La Fortezza F./ Structural Integrity Procedia 00 (2019) 000–000 For   , in this study we will use 30 years, as indicated in chapter 3.6 from the aforementioned Italian guidelines, but it would also be possible to make a different choice. Due to lack of space, it is not possible to illustrate all the mathematical passages of the calculus. In the following tables the main results are shown. 8

Table 7. Main failure costs in €

Type of damage

Cost

Cost of replacing the collapsed structural part

1'080'000 45'720'000 8'780'000 29'000'000 84'580'000

Cost of infrastructure disruption (highway tolls and alternative path for 284 days)

Social consequences (costs of 2.7 fatalities) Psychological effects (loss of reputation)

Total cost

Table 8. Strategy costs in €

Strategy

Intervention cost

Total cost 7'660'000 2'870'000

1. No interventions

0

2. Remaking of concrete surfaces every 10 years 3. Repairing and reinforcing beams after 10 years

3 x 300'000

750'000

900'000

4. Complete rebuilding of the deck

1'080'000

2'130'000

In this example, repairing and reinforcing the beams is the best strategy, as the costs of the complete rebuilding are increased by the road disruption during the works, while the repairing works are supposed to be conducted always operating from under the bridge. Incidentally, this result is compliant with both the requirements of the Italian current standards and Bulletin FIB 80.

5. Remarks

It is important to notice that some failure costs are borne only by the managing company and other costs are external and borne only by the community. That’s why the methodology proposed in this paper cannot be adopted on its own initiative by a single managing company, public or private, but it should be used to complete the current standards. Another parameter, the reference time period, is also crucial and should be defined by law. The more the time span increases, the more demanding interventions will appear necessary. The analysis shown in the previous chapters is quite simple, but to obtain reliable results, it is necessary to carefully evaluate the condition of the bridge and the geographic and economic context. The next step of the research will be how to evaluate the real effects of restoration works on the durability of the structure.

References

Contardi, A., Pasqualato, G., 2023. Assessment as to the best strategies for the maintenance of existing bridges . Life-Cycle of Structures and Infrastructure Systems, p. 2295–2302. Bulletin FIB 80, Partial factor methods for existing concrete structures. Huib van Essen, Lisanne van Wijngaarden, Arno Schroten (CE Delft), Daniel Sutter, Cuno Bieler (INFRAS), Silvia Maffii, Marco Brambilla, Davide Fiorello, Francesca Fermi, Riccardo Parolin (TRT), Kareen El Beyrouty (Ricardo), Handbook on the external costs of transport , version 2019, European Commission, Directorate-General for Mobility and Transport Ministerial Decree 16/06/2017, n. 300, Linee guida per la valutazione degli investimenti in opere pubbliche nei settori di competenza del Ministero delle infrastrutture e dei trasporti . Università, Camera di commercio e Confindustria di Genova, Effetti economici indotti dal crollo del viadotto Morandi - stime preliminari Galvagni, L., Atlantia: chiusa l’epoca Autostrade, venduta a Cassa per 8,1 miliardi. - Il Sole 24 Ore - Finanza e Mercati (06/05/22) PIARC ITALY National Committee – Technical Committee 4.2 – Bridges – 2019-2023 cycle, Bridge safety monitoring and classification – State of the art and operational recommendations .