This study deal with the elastic and inelastic structural responses of building frames under the influence of soil–structure interaction. Three give the types of moment-resisting building frames, including 5 storey, 10-storey and 15-storey buildings are selected. In addition, three soil types with the shear wave velocities less than 600m/s, representing soil classes Ce, De and Ee according to IBC-2006(3) , having three bedrock depths of 10m, 20m and 30m are adopted.
The structural sections are designed after conducting nonlinear time history analysis, on the basis of both elastic method and inelastic procedure considering elastic-perfectly plastic behavior of structural elements. The frame sections are modeled and analyzed, employing finite difference method adopting ANSYS software under two different boundary conditions: (a) fixed base (no soil–structure interaction) and (b) considering soil–structure interaction. Fully nonlinear dynamic analyses under the influence of different earthquake records are conducted. The results in terms of the maximum lateral displacements and base shears for the above mentioned boundary conditions for both elastic and inelastic behaviors of the structural models are obtained and compared, with the results. A comprehensive empirical relationship is proposed to determine the lateral displacements of the moment-resisting building frames under earthquake and the influence of soil– structure interaction.