Experimental Research On Seismic Behavior Of Steel Reinforced Concrete Columns With Special-Shaped Section

The stress of reinforced concrete special-shaped column is very complex because of its special section.The application of RC structures with special-shaped columns is restricted in high-rise building and high intensity zones considering that weak section results in low bearing capacity.Adding steel to special-shaped column is a solution.In this paper,“T-shaped steel and square steel tube” column is proposed to solve the problem that constructing traditional solid-webbed column is complicated,and its seismic behavior is studied by using both experiment and finite element method.In this paper,low cyclic loading tests are carried out on 14 special-shaped columns.The results show that bending and shear failure occur on steel reinforced concrete columns with special-shaped section,and the crushing at the bottom web is more serious.Adding steel to special-shaped column makes plastic fully developed,and energy dissipation capacity is greatly improved.Compared with the solid-webbed column,the displacement ductility factor of the “T-shaped steel and square steel tube” column can be increased by 12% ~30.8%.When the axial compression ratio increases from 0.19 to 0.39,the bearing capacity of the steel reinforced concrete columns with special-shaped section increases greatly,but the ductility increases first and then decreases.The ductility is the best when the axial compression ratio is 0.34.The finite element model is established with ANSYS,the calculation results and experimental results fit well,and the parameters were analyzed by using this model.The results show that improving concrete strength or reinforcement strength can make the bearing capacity of cross-shaped column and T-shaped column increase slightly.Improving the strength of concrete can relieve the damage of the web,but the higher the reinforcement strength,the more serious the concrete will be.The stress of steel reinforced concrete special-shaped column base is higher.The steel section in web makes more contribution,while the steel section in flange makes less contribution.Under reverse loading,the stress of section steel in web has the greatest stress in larger area,and the T-shaped section steel in web flange makes much contribution.