EXPERIMENTAL STUDY OF CONCRETE-FILLED DOUBLE SKIN STEEL TUBULAR COLUMNS WITH OCTAGON SECTION UNDER ECCENTRIC LOADS

The main parameters varied in the study are the slenderness ratio and eccentricity of load.Four concrete-filled double skin steel tubular(CFDSST) columns under eccentric loads and two columns under axial compression are studied. Based on the analysis of the experimental phenomenon in detail, some mechanic characteristics are put forward. Through the comparison with other two kinds of CFDSST (one with circular section, and the other with square section), the bearing capacity of the members is larger than that of the former and lesser than that of the latter. Finally, a simplified formula is proposed in the paper, and the calculated results are in good agreement with the test results or the mathematic results. The results are valuable for engineering designers