ABSTRACT
The behavior of concrete filled double skin steel tubular (CFDST) stub columns was experimentally investigated. Both outer and inner tubes were rectangular hollow sections (RHS). The main experimental parameter was depth-to-thickness ratio of the outer tube. Test results were also compared with those of concrete filled steel tubular (CFT) and empty SHS stub columns. Existing design codes were used to predict the load-carrying capacities of the composite sections, reasonable results were achieved. The proposed design formula considers the concrete confinement effect and steel local buckling effect.
