AISC LRFD 1.pdf

1CHAPTER AGENERAL PROVISIONSA1. SCOPEThe Load and Resistance Factor Design Specification for Structural Steel Buildingsshall govern the design, fabrication, and erection of steel-framed buildings. Asan alternative, the AISC Specification for Structural Steel Buildings, AllowableStress Design and Plastic Design is permitted.This Specification includes the list of symbols, the glossary, and the appendices.The tables of numerical values are provided for design convenience.Seismic design of buildings shall comply with the AISC Seismic Provisions forStructural Steel Buildings, Seismic Provisions Supplement No. 1, and with thisSpecification.Single angle members shall comply with the Specification for Load and ResistanceFactor Design of Single-Angle Members and with this Specification.Hollow structural sections (HSS) shall comply with the Specification for theDesign of Steel Hollow Structural Sections and with this Specification.Design of nuclear structures shall comply with the Specification for the Design,Fabrication and Erection of Steel Safety Related Structures for Nuclear Facilitiesand with this Specification.As used in this Specification, the term structural steel refers to the steel elements ofthe structural steel frame essential to the support of the required loads. Such elementsare enumerated in Section 2.1 of the AISC Code of Standard Practice forSteel Buildings and Bridges. For the design of cold-formed steel structural members,whose profiles contain rounded corners and slender flat elements, the provisionsof the American Iron and Steel Institute Specification for the Design ofCold-Formed Steel Structural Members are recommended.A2. TYPES OF CONSTRUCTIONTwo basic types of construction and associated design assumptions shall be permittedunder the conditions stated herein, and each will govern in a specific manner thestrength of members and the types and strength of their connections.Type FR (fully restrained), commonly designated as “rigid-frame” (continuousframe), assumes that connections have sufficient stiffness to maintain the anglesbetween intersecting members.Type PR (partially restrained) assumes that connections have insufficient stiffnessto maintain the angles between intersecting members. When connection restraint isconsidered, use of Type PR construction under this Specification requires that theLRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTION