Column bases in shear and normal force

Connections of steel columns to concrete foundations may be loaded by combinations of normal force, bending moment and shear force. Shear force will primarily be transmitted by friction between the base plate and the grout layer to the concrete foundation. If the compression force is small, or if tension force is present, as may occur in slender high rise structures like towers and masts, the friction will be small or absent. Then, the anchor bolts will be loaded by shear force and bending moment. At the Stevin Laboratory of Delft University of Technology, experimental and theoretical research has been carried out on column bases loaded by combinations of shear force and tension force. In the paper, the main results of this research programme are summarised. The test results and the analytical model that was developed to describe the load deformation behaviour are presented. A comparison is made with the design rules as given by the Comite Euro-International du Beton (CEB, 1994 and 1996). Based on the research, design rules for this load case were proposed to the drafting panel for the revision of Eurocode 3 from ENV to EN status (Part 1.8: Design of Joints).