Effect of column flexural characteristic on seismic behavior of braced frame with fixed column base

The presence of continuous stiff columns over height can limit the possibility of a large story drifts in concentrically braced frame (CBF) buildings. Previous studies of CBF buildings with pinned-base columns show that concentration of drift in a story may be quantified in terms of the structural ductility and the column flexural stiffness. In real braced frames, columns are not pinned at their bases, but they have some moment resistance. By fixing the bases of the columns to the foundations the period of the structure changes and the both the columns themselves, as well as the CBF, resist load making a type of "dual system" with increased redundancy. This paper investigates the behavior of CBF structures with fixed base continuous columns.