Aspects of Column Design in Tall Steel Buildings

Present design procedures (1971) for steel columns imply that each column in a story is capable of resisting a lateral force including that produced by the axial force as the structure sways under the action of the applied loads. A more economical solution may result if selected columns are designed to resist the lateral forces in a complete story; the remaining columns are then supported by these elements. This paper analyzes the techniques used to assess the stability of a 57-story steel structure designed so that rigidly connected exterior frames resist the applied lateral loads and also provide support for less stiff interior frames. The difficulties in the preliminary design are described briefly and the final solution, which includes the secondary or sway forces directly, is described in detail. In addition, the technique used for a story-by-story assessment of the ultimate strength is reported.