STUDY ON BEHAVIOR OF CONCRETE FILLED ELLIPTICAL STEEL TUBE MEMBERS PART I: SHORT AND LONG COLUMNS UNDER AXIAL COMPRESSION

摘要

This paper presents theoretical analysis of concrete filled elliptical steel tube (CFEST) members under axial compression. The theoretical analysis presents the distribution rule of interaction between steel tube and core concrete for CFEST column, which is verified and compared with both experimental tests and finite element (FE) simulations. The assumption of effective confined zone distribution of core concrete is proposed and the influence of cross-section shape on the confinement effect is analyzed. A unified axial compressive strength formula and stability factor are obtained for CFEST columns based on existing formulas for concrete filled circular steel tube (CFCST) columns.