Some issues in the numerical modelling and analysis of bridges: evidence from case studies

Finite Element Modeling (FEM) plays a crucial role in accurately simulating the structural response of bridges when subjected to design actions such as traffic loads, seismic forces, wind, thermal effects, etc. In modern engineering practice, advanced numerical modelling techniques are available, offering a wide range of options depending on the type of verification required and the expected results. Sometimes, engineers may adopt either an excessive level of simplification or an unnecessary degree of detail, depending on their confidence in numerical analyses, without fully appreciating the effects and implications that the chosen modelling criteria have on the results. This study explores the role of different modelling criteria in the safety assessment of girder bridge decks subjected to non-seismic actions (such as. traffic and wind actions). The study is performed considering two case studies characterised by different span length, deck width and slab thickness. Effects of modelling criteria in terms of stress resultants on beams and transverse load distribution are presented and discussed, demonstrating the importance of a suitable modelling of the slab with significant thickness.