Earthquake resistance is one of the most important factors for designing a building in the seismic prone area in order to reduce the earthquake damage on buildings. After earthquake events, the number of damage on buildings with setback is increases, which exhibit inadequate behaviour though they were designed according to the current state of knowledge existing in seismic codes. Most analysis will be carried out based on single earthquake as recommended by codes of practices. In reality, this is not the case, in which earthquake can occur repeatedly in the life span of the buildings. This paper studies three storeys 2D frames with regular three storeys 2D (RC) frames and irregular in elevation (setback) (RC) frame, under repeated earthquakes. Non-linear time history (dynamic) seismic analyses of buildings were employed in this paper. The seismic performance is based on the estimation of important structural parameters such as displacements and inter-storey drifts. Results of single ground motion were compared with repeated earthquakes while the regular frame was compared with irregular frame in terms of maximum lateral displacement and inter-storey drift ratio. This paper shows that regular and irregular structures which were subjected to repeated earthquakes produce higher responds than single ground motions in term of displacement demand.
Reinforced concrete; Irregular structure; Dynamic analysis; time history analysis; inter-storey drift ratio