十字形截面方钢管混凝土组合异形柱轴压承载力试验

在钢筋混凝土异形柱和异形钢管混凝土柱的基础上，提出了一种异形柱形式——十字形截面方钢管混凝土组合异形柱，通过理论计算和有限元分析得到了异形柱的破坏形态及极限承载力，并采用叠加理论推导了其换算长细比计算公式．通过轴压试验得到了计算模型的荷载位移曲线、单肢挠度曲线以及单肢荷载应变曲线．分析结果可知，叠加理论计算、有限元分析以及轴压试验的结果一致表明异形柱的破坏形态为扭转屈曲，同时3种方法得到的屈服荷载吻合较好，验证了采用叠加理论计算异形柱承载力的可行性．

Experiment of Axial Compression Bearing Capacity for Crisscross Section Special-Shaped Column Composed of Concrete-Filled Square Steel Tubes

Based on the reinforced concrete-filled special-shaped column and the concrete-filled column composed of special-shaped steel tubes,a type of special-shaped column,crisscross section column composed of concrete-filled square steel tubes,is proposed.Study on calculation method and mechanical property of crisscross section column composed of concrete-filled square steel tubes is done by three methods:superposition theory,finite element analysis and axial compression experiment.The failure mode and ultimate bearing capacity are achieved by theoretical calculation and finite element analysis.And the formula for conversion slenderness ratio is derived by superposition theory.By axial compression experiment,the curves of load-displacement for the whole member,the curves of deflection and load-strain for mono column are got.The results of theoretical calculation,finite element analysis and axial compression experiment all show that the column has a twist failure mode.Also the yielding loads attained by the three methods accord with each other well,and the feasibility of calculating the bearing capacity of the special-shaped column by superposition theory is proved.