Comparison of the effect of foundation analysis methods on structural analysis results of tall buildings

In structural analysis, there are serious interactions between soil-foundation and structure. The fixed base analysis method ignores this interaction but many analysis methods have been developed that take into account the soil-structure interaction (SSI). This paper revealed the effects of SSI analysis methods on tall buildings analysis results on soft soil sites. 6 different structural models with 20 story buildings and two different coefficients of subgrade reactions were analyzed with three different analysis methods which are fixed base method, Winkler method and pseudo-coupled method. As a result of all the analysis, 6 different structural models compared and discussed in terms of structural period, displacements, lateral loads, column, shear wall and foundation reactions and structural economy. It has been observed that the structure may remain on the unsafe side in the analysis made with the fixed base analysis method.