26

RC柱S梁混合構造における柱梁偏心接合部の構造性能

佐藤 英佑*1・安田 聡*1・成原 弘之*1・征矢 克彦*2・小室 努*2・西本 信哉*2

当社では,自由度の高い無柱空間や透明度の高いファサードを実現し,設備システムの変更・更新が容易で,幅広い要望に柔軟な対応が可能な独自の架構システム「TASMO」を開発,実用化している。TASMOは,剛性の高い壁柱とこれをつなぐ境界梁および壁柱脚部のオイルダンパーにより構成される制震システムで,地震時のエネルギーを集中的に制震装置に吸収させ,それ以外の架構の損傷を防ぐことで建物の長寿命化を可能としている。
建物外周に壁柱を配置した TASMOでは,外装材との納まりにより壁柱と境界梁が偏心して接合される。本研究では,鉄筋コンクリート造の壁柱に対し鉄骨梁が偏心して接合される柱梁接合部の構造実験を行い,破壊性状および接合部耐力,変形性能を明らかにした。また,最大耐力は,接合部内に発生するねじり耐力より評価できることを示した。

キーワード:  混合構造,柱梁接合部,偏心接合,構造実験,ねじり

*1 技術センター 建築技術研究所 建築構工法研究室
*2 設計本部 構造グループ

Structural Performance of Eccentric Beam-Column Joints Composed of Reinforced Concrete Columns and Steel Beams

Eisuke SATO*1, Satoshi YASUDA*1, Hiroyuki NARIHARA*1, Katsuhiko SOYA*2, Tsutomu KOMURO*2 and Shinya NISHIMOTO*2

At our company, a new and unique frame system called "TASMO" has been developed and put in practical use. "TASMO" has tremendous potential in architectural applications. It can provide larger building spaces and more transparent facades. Moreover, equipment systems selected using the "TASMO" system can be easily changed or refurbished in the future. The "TASMO" system consists of seismic control devices and members that remain essentially elastic throughout an earthquake and absorb most of earthquake energy applied to the building so as to avoid damage to the other members. Therefore, TASMO can secure the longer life of the building than usual.
The key to the structural design of the "TASMO" system, which has wall columns at periphery of the building, is that beams and wall columns must be connected eccentrically in order to make exterior materials fit on the walls.
Structural experiments were carried out to clarify the structural performance, such as the fracture behavior, joint strength, and deformation capacity of the eccentric beam-column joints between reinforced concrete columns and steel beams under seismic loading. The current paper is intended to provide a summary of the findings obtained from the test program. It was confirmed from the test results that the strength of the beam-to-column joint specimens under seismic loading could be evaluated by considering the torsional strength generated in the joint specimens.

Keywords:  mixed structure, beam-column joints, eccentric joints, structural experiment, torsion

*1 Building System and Material Research Section, Building Engineering Research Institute, Technology Center
*2 Structural Engineering Group, Design and Proposal Division