A Practical Method for Determining Dynamic Characteristics of Buildings Under the Effect of Foundation Rotations

Abstract

In multi-storey buildings, unforeseen foundation rotations can change the building’s behavior. Therefore, these effects should be taken into account in the analysis. In the studies conducted in the literature, the impact of the rotation of the foundation on the building behavior under static loads has been investigated. In this study, an approach is proposed to determine the dynamic behavior of buildings under the effect of foundation rotation, regardless of the type of bearing system. The multi-storey building was modeled as an equivalent flexural-shear beam in the study. In the study, the axial displacements of the columns, which are neglected in the flexural-shear beam model, are also considered, which is different from the literature. The equation of motion representing the dynamic analysis of the equivalent flexural-shear beam was solved with the help of the Differential Transform Method. The period coefficients, effective mass ratio and peak displacement coefficient for five cases were determined and plotted. A code was prepared using Matlab for the analysis with the Differential Transform Method. As a result of the study, the dynamic characteristics obtained depending on the dimensionless building behavior coefficient have been graphed. Using the given graphs, the dynamic characteristics of the buildings under the effect of foundation rotation can be determined quickly and practically. The method presented in this study can be used for Response spectrum analysis of all systems with pure shear beam, pure bending beam and bending-shear beam behavior. In addition, an approach has been proposed to consider [Formula: see text] effects within the scope of the study. The results obtained in the study were interpreted, and the impact of rotation on dynamic characteristics was discussed. At the end of the study, for the convenience of the presented method, two examples, one for wall-frame and the other for frame systems, were solved with the proposed method, and the results were compared with the SAP2000 program.