DEFORMATION CONCENTRATION PHENOMENA IN LOWER PART OF FRAMES ON COLLAPSE BY SEISMIC ANALYSIS WITH FISHBONE-SHAPED FRAMES

Abstract

This paper presents deformation concentration phenomena in lower part of frames. Steel high-rise buildings subject to extreme earthquake ground motions collapse at only lower part of frame by plastification of columns in middle story of frame. The effect of column overdesign factor to deformation concentration region is verified. Furthermore the effect of skeleton curve of members and input ground motions are also investigated. In the case of small column over design factor and the plastification occurred in columns, the collapse is observed in further lower part of a frame compared with the case of strong columns.