PSI - Issue 78

Marco Gaetani d’Aragona et al. / Procedia Structural Integrity 78 (2026) 968–975

974

3.5E+06

uncorroded 10% corrosion 20% corrosion

3.0E+06

2.5E+06

2.0E+06

1.5E+06

1.0E+06

Base Shear (N)

5.0E+05

0.0E+00

0.00

0.05

0.10

0.15

0.20

0.25

0.30

Top Displacement (m)

Fig. 4. Pushover curve for the multi-column bents considering increasing levels of corrosion

4. Conclusions This paper presents a refined finite element model to simulate the behavior of reinforced concrete multi-column exhibiting flexure and flexure-shear critical behavior subjected to corrosion phenomena. The model is developed using the OpenSees software and incorporates a mixed lumped-distributed modeling strategy to simulate the behavior of flexure-shear critical piers. The effect of corrosion is considered to affect only the flexural behavior of the piers since localized to the bottom of these members since the more aggressive environment that can be found at the base of the columns. It is considered that given the prismoid shape of the bent columns the shear failure will occur at the column top where the shear strength capacity is not affected by the corrosion that only affects the column part near the footings. Two corrosion scenarios expressed in terms of steel mass loss are considered, namely 10% and 20%. For these scenarios, the stress-strain relationship for both the concrete and steel fibers affected by corrosion have been suitably modified according to the formulations proposed in the scientific literature. The lateral performance of the multi column bridge bent has been analyzed via nonlinear static analysis. Based on the outcomings of these analyses, the following conclusions can be drawn: • The explicit simulation of brittle shear failure leads to a reduction in the lateral strength of the bent compared to the case of pure flexural behavior. While shear failure in cap beams tends to increase lateral deformability, the flexure-shear failure of the bents does not significantly reduce strength but results in an approximate 21% decrease in ultimate lateral displacement capacity compared to the flexure-dominated case. • When corrosion effects are considered, corresponding to 10% and 20% loss of longitudinal reinforcement mass, the flexure-shear hierarchy helps prevent brittle failure in the columns, resulting in pure flexural failure in both cases. For a 10% mass loss, the lateral strength is reduced by 9%, and the displacement capacity decreases by 7.4% compared to the uncorroded flexure-shear case. For a 20% mass loss, the strength reduction reaches 18%, with a corresponding 28.4% drop in displacement capacity. Although the presented results are not of general applicability, they highlight how non-uniform corrosion can influence not only the strength and ductility of RC members but also the governing failure mechanism. While this study focuses on corrosion in bridge piers, future research should investigate the global seismic performance of existing RC bridges affected by corrosion. Acknowledgements This study was carried out as part of the activities envisaged by the RETURN Extended Partnership funded by the European Union Next-GenerationEU (National Recovery and Resilience Plan – NRRP, Mission 4, Component 2,