マスダンパー効果を利用した既存中層SRC造建物の頂部減増築による制振改修設計法

摘要

耐震性の不足する中層鉄骨鉄筋コンクリート造の既存不適格建築物を対象として、減築と増築を組み合わせた新たな耐震改修工法を提案した。非線形時刻歴応答解析をとおして、本改修工法による地震応答抑制効果を検討した。%This paper presents seismic retrofitting technique of existing SRC buildings with newly added stories. A number of the stories are reduced from the top of the building. A lightweight super structure of steel moment resisting frames is newly built on the rooftop through a mid-isolation system with lead rubber bearings. Design formulae of the optimum strength and stiffness are presented through computed response surface method in terms of the maximum drift angle of the existing part. A performance curve diagram is formulated. Finally, examples of the retrofit are shown for buildings having seven or ten stories.