BRACING REQUIREMENTS OF PLANE FRAMES. IN: STRUCTURAL STABILITY RESEARCH COUNCIL. 1990 ANNUAL TECHNICAL SESSION, STABILITY OF BRIDGES, ST. LOUIS, MISSOURI, APRIL 10-11, 1990

From the point of view of limit load capacity of frames, the conventional equations for determining the required bracing size in a braced frame is generally too conservative. The semi-empirical formulas presented herein for rigid and semi-rigid frames based on a series of studies undertaken on the limit load capacity of one, two and three story frames enable the prediction of the required bracing area from strength consideration quite accurately. For a frame with relatively large horizontal loading, the drift index limit will control the design of the bracing system. When mu is greater than 2, the formulas presented here should be used carefully, because under such conditions, the lateral drift of the frame at working load level may control bracing design.