Design Philosophy for Steel Structures in Moderate Seismic Regions

The authors propose a design philosophy for steel buildings in moderate seismic regions that draws on familiar concepts of ductility and capacity design, but also integrates the concepts of reserve capacity, elastic flexibility and strength to broaden the field of design possibilities. The paper discusses structural systems representing each of these concepts: Moderate-Ductility Concentrically-Braced Frame Dual Systems—reserve capacity; Moment Frames—elastic flexibility; and Eccentrically-Braced Frames—ductility and capacity design. The paper discusses the role that strength plays in each of these concepts and its relationship to design for wind loads. In conclusion, the paper outlines the need for future research related to the continued development and validation of this philosophy.