TYPES AND LAYOUTS OF BRACING AND THEIR EFFECTS ON LATERAL STIFFNESS OF STEEL-FRAME STRUCTURES

This paper researched the influence of bracing kinds on lateral stiffness of multi-storey and high-rise braced steel-frames through calculating the biggest sidesway of the top-storey of a steel-frame braced by different types and layouts of bracing. The results show that, for different kind of bracings, the lateral stiffness of a steel frame with bracing in central spans is higher than that in side spans or other spans; for the same layout of bracing, either centrically or eccentrically braced, the herringbone bracing is better than one-way diagonal bracing in lateral stiffness and economy of the braced steel-frames. The paper suggests that, for multi-storey and high-rise braced steel-frames, the herringbone bracing should be selected and be set on middle spans as possible. The paper also points out that the centrically herringbone bracing should be preferably employed in a small and middle seismic design intensity region but the eccentrically herringbone bracing should be firstly used in a macro-seismic design intensity region.