Effects of Soil Simulation on the Interaction Analyses of Framed Structures Under 2-D and 3-D Conditions

The effects of some important factors on the development of differential settlements and flexural moments were investigated in the context of interaction analyses for two hypothetical building structures founded on a grid of strip footings. Geometrical simulations included 2-D and 3-D building models in order to identify possible differences when applying the simple 2-D simulation as against the more difficult 3-D one. Furthermore, in order to investigate the applicability of the simple linearly elastic soil model, comparisons were attempted between results obtained on the basis of linearly elastic and elastoplastic according to Mohr-Coulomb's failure criterion interactive analyses. The variation of differential settlements (or rotations), bending moments and axial loads of the superstructure and foundation were studied versus the elastic modulus E or versus the global safety factor. Detailed conclusions were deduced based on representative diagrams. The comparisons between corresponding results obtained by 2-D and 3-D simulations indicated significant differences especially in cases of high relative rigidity, influenced by the thickness of the compressible soil layer. The comparisons between linearly elastic and elastoplastic soil simulation showed the important role of the relative rigidity in the interaction problem, especially for low values of the global safety factor.