採托架支承配置挫屈束制支撐之新建RC構架設計、試驗與抗震性能分析

Seismic Design and Tests of the Beam-column Joint in a Buckling-Restrained RC Braced Frame

林庭立(Ting-Li Lin) ； 吳安傑(An-Chien Wu) ； 王孔君(Kung-Juin Wang) ； 蔡克銓(Keh-Chyuan Tsai)

《結構工程》 33卷1期 (2018/03) Pp. 84-102

https://doi.org/10.6849/SE.201803_33(1).0004

摘要

本文針對採Z字形（zigzag）配置挫屈束制支撐（buckling-restrained brace, BRB）於新建鋼筋混凝土（reinforced concrete, RC）構架中的接合介面進行探討，依據現行耐震設計規範提出一棟含BRB之12層樓RC結構設計例。為了解所提接合方式之施工性與耐震性能，擷取設計例中位於10樓的RC梁柱接頭處進行細部設計，並製作含接合板基座及托架之實尺寸梁與柱節點子結構試體進行反覆載重試驗。試驗結果顯示，接頭處之接合板基座及托架未發生明顯損壞，可有效傳遞BRB與RC構架間的力量，並證實所提接合方式之設計與施工方法可供工程實務應用。為更進一步探討整體結構系統受震反應，本研究採用三種地震危害度（SLE, DBE and MCE）共240組含近斷層之地震加速度歷時進行非線性動力歷時分析。分析結果顯示，整體結構系統高模態振動反應並不顯著，三種危害度地震下BRB最大抗層間側力比例平均值分別為23%（SLE）、21%（DBE）及19%（MCE）；DBE及MCE等級地震下，最大層間側位移角則分別為0.0182及0.0232弧度。此外，接合板基座之最大水平向拉力需求可採相鄰兩組BRB可能發展之最大拉力強度水平向合力之70%進行設計。

關鍵字

挫屈束制支撐 ； 鋼筋混凝土結構 ； 托架 ； 梁柱接頭 ； 非線性動力歷時分析

並列摘要

In this study, the brace connection performance in the new reinforced concrete (RC) frame buildings with buckling-restrained braces (BRBs) arranged in a zigzag configuration is investigated. A 12-story buckling-restrained braced RC building is proposed following the model building codes as a prototype. In order to verify the constructability and the seismic performance of the proposed connection, the beam-column joint at the tenth floor selected as the sub-assemblage specimen was designed and fabricated. The full-scale sub-assemblage, including the BRB gusset bracket and a pair of RC corbels, in the proposed BRB-RCF structural system was tested using cyclic loading procedure. Test results demonstrate that the proposed BRB-to-RC connection details performed very well without failure in the steel gusset bracket or the RC corbels. The design and construction of the sub-assemblage specimen show the feasibility of the proposed system for practical applications. In order to further gain insights into the seismic performance of the BRB-RCF system, nonlinear response history analyses were conducted using a total of 240 (SLE, DBE and MCE) ground accelerations. Analysis results indicate that the mean maximum total BRB shear to base story shear ratios are about 23%, 21% and 19% for SLE, DBE and MCE, respectively. The maximum inter-story drift ratios under the DBE and MCE events are 1.82% and 2.32%, respectively. Analysis results also suggest that the high mode effect is moderate. It is found that the peak demand of the horizontal tension force on the gusset bracket can be estimated by considering 70% of the sum of the horizontal force components computed from the maximum tension strengths of two adjacent BRBs.

並列關鍵字

buckling-restrained brace ； reinforced concrete structure ； corbel ； beam-column joint ； nonlinear response history analysis