Metalica

LOAD AND RESISTANCE
FACTOR DESIGN
SPECIFICATION

For Structural
Steel Buildings
December 27, 1999

Load and Resistance
Factor Design Specification
for Structural Steel Buildings
December 27, 1999

Supersedes the Load and Resistance Factor Design Specification
for Structural Steel Buildings dated
December 1, 1993 and all previous versions.
Prepared by the
American Institute ofSteel Construction, Inc.
Under the Direction of the
AISC Committee on Specifications and approved by
the AISC Board of Directors.

AMERICAN INSTITUTE OF STEEL CONSTRUCTION, INC.
One East Wacker Drive, Suite 3100
Chicago, Illinois 60601-2001

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Copyright © 2000
by
American Institute of Steel Construction, Inc.
All rights reserved. This book or any part thereof must not be reproducedin any
form without the written permission of the publisher.
The information presented in this publication has been prepared in accordance with
recognized engineering principles and is for general information only. While it is
believed to be accurate, this information should not be used or relied upon for any
specific application without competent professional examination and verification ofits accuracy, suitability, and applicability by a licensed engineer, architect or other
professional. The publication of the material contained herein is not intended as a
representation or warranty on the part of the American Institute of Steel Construction, Inc. or of any other person named herein, that this information is suitable for
any general or particular use or of freedom frominfringement of any patent or patents. Anyone making use of this information assumes all liability arising from such
use.
Caution must be exercised when relying upon other specifications and codes developed by other bodies and incorporated by reference herein since such material may
be modified or amended from time to time subsequent to the printing of this edition.
The American Institute of SteelConstruction, Inc. bears no responsibility for such
material other than to refer to it and incorporate it by reference at the time of the
initial publication of this edition.

Printed in the United States of America

LRFD Specification for Structural Steel Buildings, December 27, 1999
AMERICAN INSTITUTE OF STEEL CONSTRUCTION

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PREFACE

The AISC Load and Resistance Factor Design(LRFD) Specification for Structural Steel
Buildings is based on reliability theory. As have all AISC Specifications, this Specification has been based upon past successful usage, advances in the state of knowledge, and
changes in design practice. This Specification has been developed as a consensus document to provide a uniform practice in the design of steel-framed buildings. The intention
is toprovide design criteria for routine use and not to provide specific criteria for infrequently encountered problems, which occur in the full range of structural design.
This Specification is the result of the consensus deliberations of a committee of structural
engineers with wide experience and high professional standing, representing a wide geographical distribution throughout the U.S. Thecommittee includes approximately equal
numbers of engineers in private practice and code agencies, engineers involved in
research and teaching, and engineers employed by steel fabricating and producing companies. The contributions and assistance of more than 50 additional professional volunteers working in 15 task committees are also hereby acknowledged.
The Symbols, Glossary, and Appendices tothis Specification are an integral part of the
Specification. A non-mandatory Commentary has been prepared to provide background
for the Specification provisions and the user is encouraged to consult it.
The principal changes incorporated in this edition of the Specification include:
• Dual units format. Values and equations are given in both U.S. customary
and metric units. The metric...