Ultimate Bearing Capacity Research On The Steel Tube Composite Column Filled With Steel Reinforced Concrete

The steel concrete composite structure is extensively used in high-rise and super high-rise buildings due to its high performance, ease of construction, architecture features and other economical reseasons, Many investigations have been carried out on concrete filled steel tube. However, the behaviour of composite columns filled with reinforced concrete has not been widely studied.In this paper, the bearing capacity of the steel tube composite columns filled with steel reinforced concrete is analyzed based on thick-walled cylinder elastic-plastic limit analysis, A reasonable match was reached by comparing the theoretical analysis with the test results. The principal results are as follows.Using the thick-walled cylinder elastic-plastic limit analysis (TCELA), the solution of the steel tube composite column filled with steel reinforced concrete under axial compressive is obtained. Parametric studies was performed to investigate, and the influcing factors. The theory results calculated with the TCELA and the united strength theory (UST) are in good agreement with the literature.data and it shows that the Yu-Maohong UST and the TCELA is feasible for the steel tube composite column filled with steel reinforced concrete. The tension-compression ratio,the intermediate principal stress and the steel-reinforced rate have an important effect on the bearing capacity of the steel tube composite column filled with steel reinforced concrete. The ultimate load is increasing with the increasing of these three important factors. Based on the analysis of SRC columns with steel circle pipe, the optimized reinforcement ratio,optimized stirrup ratio and the optimized steel-reinforced rate are obtained. The stress-strain curve and stress contour of square steel tube short columns filled with steel-reinforced self-consolidating high-strength concrete are analyzed based on the commercial finite element analysis software ANSYS. The perfect bond between steel tube and concrete, reinforced steel and core concrete are assumed. Compared the theory value with numerical simulation value, it can be found that the results are in reasonable agreement. The difference of failure mode can be obtained by the post-processing of the ANSYS. Through the stress contour of the steel tube and the steel reinforced, it can be found that the steel tube and steel reinforced have reached yield strength in an ultimate limit state. It shows that the bearing capacity is considerably improved due to the core concrete suffering from three-directional pressure.