Study On Seismic Behaviors Of High Strength Concrete-filled Rectangular Steel Tube Columns

The concrete-filled square steel tubular columns attracts more and more attention in engineering field due to high bearing capacity,the better flexural rigidity,convenient construction and other advantages. Up to now, there are a large number of experimental researches on earthquake resistant properties of concrete-filled square steel tubular column, but the experimental researches focus on common concrete. There are a few experimental researches on earthquake resistant properties of high concrete-filled square steel tubular columns. Base on the investigation of research and application on concrete-filled square steel tubular column in China and abroad. The test is conducted about eight high concrete-filled rectangular steel tubular columns under low frequency cyclic load. The parameters include ratio of axial compression force,steel ratio and slenderness ratio. The hysteretic features,degradation of stiffness,failure mechanism and characteristics are researched. The effects of different parameters are compared.The experimental results showed that the concrete-filled square steel tubular columns have the plump hysteretic curve,good deformation ability after the specimens reach ultimate loads under high ratio of axial compression force,The ductility coefficient are between 3.05and 4.07, the columns can meet the requirement of ductile specimens. The rigidity degradation of columns is low. The specimens have good energy dissipation capacity. The results indicate that high concrete-filled rectangular steel tubular column has excellent earthquake resistant properties. The ratio of axial compression force is most important, so the limited values of axial compression of ratio of high concrete filled square steel tubular columns are brought forward on the basis of the deduced result and experimental data.The finite element model of high concrete-filled rectangular steel tubular columns is proposed by finite element software ABAQUS. The numerical simulation of hysteretic curve is conduct under cyclic loads. The finite element results agree well with the experimental data. Base on the full-range analysis of high concrete-filled rectangular steel tubular columns, and the change of stress distribution on typical section is research. The parametric study of load to displacement curves of high concrete-filled rectangular steel tubular column were carried out based on the finite element model in this paper. The steel ratio of the column, concrete strength, steel strength, axial load level of column, slenderness ratio, stiffness ratio of beam to column, were all considered as analysis parameters. They may be referred for design of high concrete-filled square steel tubular column. The research fruits can be used to direct the engineering practice of concrete filled steel tube structure.