Progressive collapse resistance of a composite steel and concrete structural frame

Abstract

During the past decade, numerous research studies have been conducted on building structures to resist progressive collapse. In the study reported in this paper, a new type of octagonal partially encased composite column was tested and analysed under compressive loads. A comprehensive finite-element analysis was then conducted to estimate the structural behaviour of composite steel and concrete frames under the loss of a column. Push-down and non-linear dynamic analyses were conducted to investigate the resistance of frames against progressive collapse, including collapse-resistance force, hinge-development mechanism, flexural stiffness and displacement ductility. The analysis showed that making use of partially encased composite columns can provide alternative paths for transferring loads originally only supported by the beams, thus improving the collapse-resistance capacity of the steel frame. The partially encased column, however, may reduce the ductility of the steel frame and may change the failure mode of the frame. Also, none of the beam–column connections can meet plastic rotation criteria.