» The impulse in software technology and computational power of personal computers has recently offered the possibility to perform fully-3D finite element analyses of complex engineering projects. In particular, in the field of civil engineering it is nowadays feasible to perform the analysis of a soil-structure interaction problem by a unique model, accounting at the same time for both geotechnical and structural issues.

The three-dimensional version of the finite element code PLAXIS includes a wider choice of structural elements (such as beams, plates and node-to-node anchors), enhancing its modelling capability at the cost of a deeper structural competence required to the user. This paper provides a contribution on this specific topic, illustrating a number of structural models, where the different structural elements were employed, to investigate and clarify their response under different loading conditions. These models range from simple single-bay spatial frame to multistorey frame with cross-bracings simulating the presence of infilled panels. All the models are assumed fixed at base, ie no foundation systems were considered, in order to focus the attention on the structural response only.