Design method of concrete filled thin-walled steel tube column-foundation connections

•Parametric analyses are conducted to investigate the performance of CFST column-foundation connections.•Sectional strength models are proposed for CFST column-foundation connections.•Elastic stiffness models are proposed for CFST column-foundation connections. The anchor rebar column-foundation connection (SAC) has been proposed for the concrete filled steel tube (CFST) column. To enhance the load transfer between the steel tube and concrete, shear hoop rings or perfobond strips (PBLs) could be used, forming the SAC-H and SAC-P, respectively. Anchor rebars could be directly welded onto the surface of steel tube (SAC-W) to transfer the axial load. To date, experimental studies have been conducted to investigate the seismic performance of the four novel types of column-foundation connections. To facilitate the application of the proposed connections, design methods are explored and proposed in this paper. A test database is assembled first, followed by the development of the finite element model (FEM). On the basis of a parametric study, design methods for the sectional strength and elastic stiffness are proposed.