復旧時の死荷重支持機構を埋め込んだRC単柱に対する実験的検討

Abstract

橋梁構造の危機耐性実現に向けて, 地震被害後の復旧性向上につながる構造技術が求められている. そこで本研究では, 死荷重支持機能を有する鋼管拘束コンクリート柱を埋め込んだRC単柱を提案し, 正負交番載荷実験により, その性能を検証した. その結果, 鋼管底面とフーチング上面が一致するよう鋼管拘束コンクリート柱を配置することで, 鋼管拘束コンクリート柱へ引張力が伝達されず, RC柱変形時の鋼管拘束コンクリート柱の損傷が軽減されることがわかった. また提案構造は, 通常のRC柱と類似した復元力特性および終局モードを示すことがわかった. そして実験終了後, RC柱の軸方向鉄筋および鋼管周囲のコンクリートを撤去した結果, 鋼管拘束コンクリ―ト柱のみで作用軸力を支持できることが確認でき, 復旧性の高い構造であることがわかった.

In order to realize anti-catastrophe of bridge structures, the structural technology to secure human life and improve the recoverability is required. In this study, a RC column with an embedded concrete filled steel tube with dead weight support capacity was proposed, and its performance was evaluated by cyclic loading tests. In the proposed structure, the embedded concrete filled steel tube was placed so that the bottom of the steel tube and the top of the footing were aligned. As a result, it was possible to prevent the tensile force from being transmitted to the embedded concrete filled steel tube and reduce damage to it. It was also found that the proposed structure exhibits restoring force characteristics and ultimate modes similar to those of ordinary RC columns. After the experiment, the longitudinal bars and the concrete surrounding the embedded concrete filled steel tube were removed. From the results, it was confirmed that the acting axial load could be supported only by the remaining concrete filled steel tube.