Seismic Behavior and Deterministic Design Procedures for Steel V-Braced Frames

Abstract

This paper presents an approach for designing low-rise steel framed buildings with inverted-V-bracing for severe earthquakes. A deterministic design philosophy is used with respect to earthquake-resisting ductile steel braced frames. Seismic behavior of steel frames with inverted-V-bracing is discussed. A series of dynamic analyses was performed on a two-story inverted-V-Braced frame, subjected to near-field ground motions. Ground shaking of this type may be expected in New Zealand, within 10 to 15 km from the Wellington fault, or in the United States in Seismic Zone 4. Post-elastic behavior of braces, beams, and columns is discussed. From the results of dynamic analyses, the interrelations between the seismic forces in frame members are identified. The expressions for the maximum expected seismic design actions in those elements are derived, following the capacity design method. It is believed that this approach will result in stronger and more ductile frames that are capable of resisting the near-field ground motions.