CALCULATION FOR BEARING CAPACITY OF CONCRETE-FILLED STEEL SQUARE TUBE COLUMN WITH BINDING BARS SUBJECTED TO AXIAL LOAD

The formulae for calculating bearing capacity of square concrete-filled steel tube (CFT) stub column with binding bars subjected to axial load are deduced based on the constitutive relationship of square concrete-filled steel tube, which are followed by a simplified method for the need of applying in practice conveniently. A calculation for the ultimate bearing capacity of square CFT stub columns with or without binding bars is conducted by the formulae put forward in this paper, the method of EC4(1996) and that of GJB(2000) respectively. The comparison between the results of calculation and those of experiments show that: 1) for the square CFT stub columns without binding bars, results got by all of the three methods are reasonable and close to each other; 2) for the square CFT stub columns with binding bars, results got by the method put forward in this paper are more reasonable because of considering the confining effect of binding bars.