PSI - Issue 78

Manuel Capogna et al. / Procedia Structural Integrity 78 (2026) 1064–1070

1068

These spreadsheets simulate various scenarios, allowing for the input of segment-specific data related to structural conditions, material properties, and exposure to different hazards. Microsoft Excel provides a flexible way to calculate attention classes at a granular level, based on the methodology outlined in the Italian Guidelines for the classification and risk management, safety assessment, and monitoring of existing bridges (Italy, 2022). This includes the determination of a "seismic attention class" considering peak ground acceleration, topographic category, subsoil category, and the bridge's structural scheme, span, and materials. Furthermore, it allows for the estimation of "hydraulic and landslide attention classes" and their combination into a comprehensive multi-hazard attention class for each segment (See Fig.4a). The model can also generate a diffusion index table to represent the spatial distribution of risk levels along the bridge (See Fig.4b). This granular output provides a clearer picture of localized vulnerabilities, enabling bridge managers to identify specific sections requiring immediate attention or specialized monitoring. The second simulation was carried out on the Zárate and Brazo Largo bridges. These are two almost identical cable-stayed road and rail bridges that cross two branches of the Paraná River delta: the Paraná Guazú and the Paraná de las Palmas. These branches are about 30 kilometers apart, located between the cities of Zárate (Buenos Aires Province) and Brazo Largo (Entre Ríos Province) in Argentina. The bridge over the Paraná de las Palmas River was named after General Bartolomé Mitre, while the one over the Paraná Guazú was named after General Justo José de Urquiza. Both bridges are part of the General Urquiza railway system.

Fig. 5. Road and railway bridges over the Paraná del las Palmas and Paraná Guazú rivers – Longitudinal section and plan

Attention Class

Total sections

37

1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637

Structural and Foundational Seismic

5 0 0 0 0

4 2 0 0 0

3 4 0 4 0

2 6

Partial Attention Class (Sections)

1

Structural and Foundational

25

Hydraulics Landlslides

Seismic

37

0

Hydraulics Landlslides

4 0

29 37

Attention Class

1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637

Overall

5

4

3

2

Partial Attention Class (%) Structural and Foundational

1

0.00% 5.41% 10.81% 16.22% 67.57% 0.00% 0.00% 0.00% 100.00% 0.00% 0.00% 0.00% 10.81% 10.81% 78.38% 0.00% 0.00% 0.00% 0.00% 100.00%

Seismic

Attention Class

1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637

Hydraulics Landlslides

Structural and Foundational Seismic Overall Hydraulics and Landslides

SI

Total sections

37

Attention Class

1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637

5 0

4 2

3 6

2 4

1

Hydraulics Landlslides Overall Hydraulics and Landslides

Overal Attention Class (Sections)

25

Overal Attention Class (%)

0.00% 5.41% 16.22% 10.81% 67.57%

(a)

(b)

Fig. 6. Road and railway bridges over the Paraná del las Palmas and Paraná Guazú rivers – Attention classes for each individual segment (a) and diffusion indexes (b)