摘要 本研究針對24根以H型鋼與RC所組成之鋼骨鋼筋混凝土實尺寸構材，探討其在軸力與雙向彎矩作用下之耐震行為，研究主要參數為斷面之不同鋼骨與全斷面之強度比及雙向彎矩大小。研究發現，由於弱軸方向受壓側由混凝土提供大部分的壓應力，弱軸方向的鋼骨貢獻較小，所以在RC部分之強度固定下，提高鋼骨與全斷面之強度比，構材受壓側混凝土壓應力將因之提高，使得混凝土提早碎裂，強度衰減越快。再者，因斷面弱軸之影響，導致構材在軸力與強弱軸雙向彎矩作用時，若增加鋼骨與全斷面之強度比，其變形能力與能量消散能力反因之降低。由試驗結果亦發現，為求得較佳之構材耐震行為，斷面強弱軸之強度比需適度調整，本研究建議其值為2.2至2.5。 ABSTRACT This study investigated the seismic performance of 24 composite columns composed of H-steel and reinforced concrete. Major parameters studied included the sectional strength ratios and the magnitudes of biaxial bending. It was found from test results that member performance was governed by the strength of reinforced concrete when they were loaded in the section’s weak axis. It was also observed that the performance of member with weak axis bending decreased when the section’s steel strength increased. Test results suggested that the strength ratio between the section’s strong and weak directions be adequately adjusted so that high member performance could be achieved. It is proposed in this study that the ratio be set to 2.2 and 2.5.