ABSTRACT
The repetition of strong seismic actions during a seismic sequence has been observed in many parts of the world and requires new assessments of the effects on structures. In this paper, the responses of five types of single degrees of freedom structural systems and a 3-storey, 2-bay moment resistant steel frame have been analysed when subjected to repeated seismic events of medium-strong intensity. Obtained results show that for SDOF and steel frame seismic responses there is a significant increase in the required ductility or strength, particularly for structures with a period less than about 1.5s with an elastic-perfectly plastic behaviour.
