This study evaluates the movement of a frame built on soft soil under seismic excitation taking into account soil-structure interaction. First, the study was evaluated using the finite element method, then, by using a substructure method which modelled the soil using springs and dampers in a linear and nonlinear study. Rheological models were determined using impedance functions, calculated using a numerical program CONAN. These dynamic impedances are shown in the displacement vector of a three-degrees-of-freedom frame, which was calculated on the basis of lateral forces distributed over the structure height using the equivalent static method. In this regard, two different calculation norms were chosen; RPA2003 and UBC97. Finally, a paramet...