Recent advances in research on seismic performance of vertical irregular structures and applications to seismic codes

Verticalirregularities of buildings are the major factor which initiatesor aggravates the damage failure of structures. In order toimprove our understanding of the seismic conceptual design ofstructures with vertical irregularities, this paper presents thedefinition of the irregularities of buildings along verticaldirection, such as stiffness irregularity, strength irregularityand mass irregularity, the main contents and the damagecharacteristics under the earthquake actions. The recent researchprogress in seismic response demand of vertical irregularreinforced concrete structures are summarized, together withrelevant articles of limitations on vertical irregular structuresdescribed in the current building design codes. Finally, promisingdirections for future research in this area are suggested on thebasis of the current situations.