The total energy input exerted by an earthquake is a very stable amount which is mainly influenced by the total mass and the fundamental natural period of structure. On the other hand, the damage distribution is very sensitive to the strength distribution of structure. When the top story of the multi-story frame is sufficiently weaker than the other stories, the total damage can be concentrated in the top story, leaving the other stories undamaged. To realize such a structure, the top story must be equipped with flexible slender columns supporting vertical loads and the relatively stiff elements which can absorb almost all of energy input. This paper investigates experimentally the ultimate load-carrying capacity of flexible slender columns under large amplitude of translational deflections. As a result, a high possibility of.such a type of structure is demonstrated.
