Torsional bracing of columns

Many column bracing details employed in steel construction do not prevent t wist, and subsequently, torsional buckling may control the column capacity. This mode of buckling is not adequately considered in design codes and is often overlooked. This paper documents a finite-element investigation of th e torsional buckling behavior of columns with lateral bracing located at di fferent points on the cross section. The location of the lateral bracing on the cross section has a significant effect on torsional buckling. Equation s are developed for the stiffness and strength requirements of bracing to c ontrol torsional buckling. Details for torsional bracing are discussed and presented. A connection detail must Ire provided between the column and the brace that controls cross-sectional distortion. A design example illustrat es the use of the bracing recommendations.