Study Of The Method For Design And Calculation Of Hsc Columns Reinforced With Concrete Filled Steel Tube

The design and calculation method of high strength concrete columns reinforced with concrete filled steel tube, a new kind of structural member developed in construction practice, is presented based on experimental and theoretical analysis. Main researches are carried out as follows:Experiments of the short columns under axial compression are carried out to investigate the mechanical properties such as the failure feature, ductility and the coordinated working performance. Based on the test results, the formula for calculating the ultimate strength is established.On the basis of seismic behavior experiments of high strength concrete columns reinforced with concrete filled steel tube, there are two methods for calculating flexural strength of the column being discussed. One method is based upon the method in building code for calculating the flexural strength of reinforced concrete member, while the other is based upon the method of superposition. In the further research, the moment梐xial load relationship of the column under eccentric compression is analyzed using finite element method. The results are in good agreement with the experimental results.On the basis of shear resisting behavior experiments of the column, the formula model for calculating the shear strength of the column is presented, and the undetermined coefficient in the formula is regressed using the experimental data.According to the test results of seismic behavior experiments, the limited values of axial compression ratio and limited values of axial force for high strength concrete columns reinforced with concrete filled steel tube are proposed based upon the condition of displacement ductility needed for earthquake-resistance.The feasibility of applying neural networks to evaluate the performance of the columns is investigated. Two prediction models, one for earthquake-resistance property and the other for ultimate shear strength, are established. In the further research, the influence of various parameters on the earthquake-resistance property and ultimate shear strength are discussed.Application of the column in engineering is introduced on the background of the construction of Liaoning Product Large Building. Three kinds of beam-column node are recommended.