Behaviour of a simple column base connection

Abstract

This paper presents the results of an experimental investigation on the behaviour of steel column base connections. The connection is effected by means of a steel base plate welded to the lower end of the column and attached to the concrete footing with two or four anchor bolts. The testing program comprised 15 specimens. The measured moment–rotation curves were used to determine the fixity factors of the base connections, taking into account the presence of an axial compression load.The results indicate that the compression force in the column significantly increases the flexural stiffness of the base connection and that the rotational restraint offered by the column base is sufficient to be considered in design. The results also show that the method of analysis used to determine the ultimate moment capacity of the base connection is conservative. Key words: steel column, column base connection, moment–rotation curve, anchor bolt, flexibility factor, fixity factor.