PSI - Issue 84

Beatrice Baldan et al. / Procedia Structural Integrity 84 (2026) 569–574

573

Figure 3 Analytical vs experimental results expressede as ratio between the loads

5. Conclusions This study evaluated the reliability of strut-and-tie models for assessing the ultimate capacity of Gerber half-joints in existing bridges. A comparative analysis between analytical predictions and experimental data revealed a systematic trend: the elastic model provides safe-sided but significantly conservative estimates, underpredicting experimental capacity by up to 78%. The results underscore that conventional design-oriented elastic models fail to capture the nonlinear load transfer and plastic redistribution occurring at ultimate conditions. In contrast, a simplified plastic rotational analysis demonstrated closer alignment with experimental failure loads, suggesting that limit analysis approaches are more appropriate for structural assessment. In summary, this work highlights the need to move beyond purely elastic design models toward simplified, plastic based assessment tools. Adopting such approaches would enable more realistic and economically sustainable evaluations of existing critical details, supporting better-informed maintenance and retrofit decisions for aging infrastructure.

References

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