Analysis of Multi Story Frames Subjected to Multiple Support Excitation by Using Displacement Loading

Abstract

In seismic analysis of structures, generally it is assumed that all supports are subjected to identical ground motions. This approach is assumed to be realistic when the foundation of the structure is formed as a rigid plate, but it cannot consider the dynamic effects of the earthquake wave propagation if the supports are able to move independently. In this study, the multi-support excitation analysis of multi-story, multi bay frames is performed by using displacement loading which defines the seismic load depending on the ground displacement. The modal analysis procedure of the structures subjected to multi-support excitations is given in detail and the effect of pseudo-static displacement on the dynamic response of the structure is highlighted. A static correction approach is implemented with a numerical example to reflect the higher mode effects which are a natural result of displacement loading.