Study On Biaxial Bending Seismic Behavior Of Steel Reinforced High-strength Concrete Columns Under High Axial Compression Ratio

With the rapid development of high-rise buildings, steel reinforced high-strength concrete columns are widely used as vertical load-bearing member. This new member has the advantages of concrete and steel, which has good axial bearing capacity and seismic performance. However, researchs on SRC columns are so limited, especially the seismic performance of steel reinforced high-strength concrete columns in high axial compression. SRC columns are often in biaxial bending because of wind load, horizontal earthquake, floor layout and unequal load distribution of vertical force factors. There are few studys on seismic performance of SRC column in biaxial bending and axial compression. Besides, the size effect as well as resulting difference caused by structural changes is lack of verification due to capacity constraints of the loading equipment and cross-sectional of specimen is so small.2CFST columns,1SRC column and1RC column were tested under cyclic load. Failure mechanism, failure modes and hysteretic of specimens were discussed. The influence of hysteresis curve, skeleton curve, energy dissipation, deformation capacity and stiffness degradation due to the factors of axial compression ratio, cross-section form of steel bone and steel ratio were analysed. Theoretical analysis of axial force shared by concrete filled tubular were made. The tests results show that high-strength concrete and steel reinforce can work together well. It can saticfy flat section assumption and The columns wi th high-strength concrete and steel can effectively improve the bearing capacity and deformation. They have good seismic performance. The section type of SRC has little effect on seismic performance. But, axial compression ratio is an important factor to the ductility of SRC columns. Higher axial compression ratio, lower ductility of columns. Researches above provide reference value to further understand the seismic performance of this new column.A nonlinear analysis were used the finite element software ABAQUS6.10. Steps from the way of building finite model to calculation results were introduced The finite element analysis results were compared with experimental results.