Page 221 - Structural Steel Designers Handbook AISC, AASHTO, AISI, ASTM, and ASCE-07 Design Standards

Brockenbrough_Ch05.qxd 9/29/05 5:12 PM Page 5.1

Source: STRUCTURAL STEEL DESIGNER'S HANDBOOK

CHAPTER 5

CRITERIA FOR BUILDING DESIGN

Roger L. Brockenbrough, P.E.
President
R. L. Brockenbrough & Associates, Inc.
Pittsburgh, Pennsylvania

Buildings should be designed to meet the requirements of state or local building codes. For the design
of the structural steel framework, most codes refer to the specifications of the American Institute of Steel
Construction (AISC), One East Wacker Drive, Suite 700, Chicago, IL 60601-1802 (www.aisc.org).
In 2005 the AISC published a new document, “Specification for Structural Steel Buildings.”
Referred to herein as the AISC Specification, it is known as a unified specification because it com-
bines allowable strength design (ASD) and load and resistance factor design (LRFD) in a single
specification. This chapter provides a summary of the main provisions of the AISC Specification and
insight for design application.
The AISC Specification now provides common requirements for nominal strength, such that the
ASD and LRFD design methods now differ mainly in the alternative use of safety factors or load and
resistance factors. Also included are design requirements for certain members that were previously
addressed in separate documents, such as angle members and hollow structural sections (HSS). The
AISC Specification applies to the design, fabrication, and erection of structural steel for buildings,
as well as for other structures designed, fabricated, and erected in a manner similar to buildings, i.e.,
with building-like vertical and lateral load-resisting systems.
The design of structural steel in seismic zones should also comply with the AISC’s “Seismic
Provisions for Structural Steel Buildings” (2005). The seismic provisions apply when the seismic
response modification coefficient R, as specified in the applicable building code, is greater than 3.0.
The design of nuclear structures should comply with the requirements for ASD given in the
“Specification for the Design, Fabrication, and Erection of Steel Safety-Related Structures in Nuclear
Facilities,” including Supplement No. 2 (ANSI/AISC N690-94), or with the “Load and Resistance
Factor Design of Safety-Related Steel Structures for Nuclear Facilities” (ANSI/AISC N690L-03).
The design of structural members other than HSS that are cold-formed to shape from steel not
more than 1 in (25 mm) thick should be based on the “North American Specification for the Design
of Cold-Formed Steel Structural Members” (2001), and “Supplement” (2004), published by the
American Iron and Steel Institute (AISI), Washington, D.C., as discussed in Chap. 9.

5.1 MATERIALS, DESIGN METHODS, AND
OTHER CONSIDERATIONS

5.1.1 Materials
The AISC Specification recognizes the following structural steel materials as designated by ASTM
Standards. Information on most of these is given in Chap. 1.

5.1
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