鋼筋混凝土柱為建築物傳遞重力載重及抵抗地震側向力之主要垂直承載構件，其於地震作用下除承受上部結構傳遞之軸向力外，亦須抵抗彎矩與剪力。特別對於低樓層柱構件而言，承受較高軸壓力，若無法於非線性變形後維持足夠之軸向承載能力與側向變形能力，可能導致結構嚴重受損、傾斜甚至倒塌。因此，受高軸壓力鋼筋混凝土柱之耐震變形能力，為確保建築物整體耐震安全的重要關鍵。 本研究共設計五組實尺寸鋼筋混凝土柱試體，試體斷面尺寸為 650 mm × 650 mm，柱淨高為2500mm，高寬比為3.85。試體之縱向主筋分別採用#11（D36）SD550W 與#10（D32）SD550W，橫向圍束鋼筋之設計強度f_yt分別採用420 MPa與550 MPa，混凝土設計抗壓強度為42MPa 及63MPa，以探討橫向圍束鋼筋設計強度與混凝土抗壓強度比值(n_c)之值介於8.7至13.1之耐震性能，並驗證n_c值小於12方能提供3% 弧度變形之可靠性，並進一步研究固定軸力及變動軸力之載重形式對受高軸壓力柱構件之耐震變形容量的影響，評估維持前版規範之縱向鋼筋隔根提供耐震橫向圍束鋼筋之可行性。;Reinforced concrete (RC) columns are the primary vertical load-carrying members responsible for transferring gravity loads and resisting earthquake-induced lateral forces in buildings. During earthquakes， columns are subjected not only to axial loads transferred from the superstructure but also to bending moments and shear forces. This is particularly critical for columns at lower stories， which are typically subjected to high axial loads. If these columns cannot maintain sufficient axial load-carrying capacity and lateral deformation capacity after undergoing nonlinear deformation， severe structural damage， excessive inclination， or even collapse may occur. Therefore， the seismic deformation capacity of RC columns subjected to high axial loads is essential to the overall seismic safety of buildings.
This study designs five full-scale RC column specimens with cross-sectional dimensions of 650 mm × 650 mm， a clear height of 2500 mm， and an aspect ratio of 3.85. The longitudinal reinforcement consists of #11 (D36) SD550W and #10 (D32) SD550W bars. The design strengths of the transverse confinement reinforcement， f_yt， are 420 MPa and 550 MPa， while the specified compressive strengths of concrete are 42 MPa and 63 MPa. The specimens are designed to investigate the seismic performance of RC columns with ratios of transverse reinforcement design strength to concrete compressive strength， n_c， ranging from 8.7 to 13.1. The study also examines the reliability of using an n_c value below 12 to provide a deformation capacity of 3% drift ratio.
Furthermore， the effects of constant and variable axial-load histories on the seismic deformation capacity of RC columns subjected to high axial loads are investigated. The feasibility of retaining the detailing requirement in the previous code edition， in which seismic transverse reinforcement provides lateral support to every other longitudinal bar， is also evaluated.
