Structural Design Guide: To the AISC (LRFD) Specification for Buildings

296 Pages·1996·15.83 MB·English

by  Edward S. Hoffman

STRUCTURAL
DES I G N
G U IDE
SECOND EDITION
STRUCTURAL
D E S I G N
G U I D E
To AISC (LRFD)
THE
SPECIFICATION FOR BUILDINGS
SECOND EDITION
Edward S. Hoffman
Albert S. Gouwens
David P. Gustafson
Paul F. Rice
CHAPMAN & HALL
New York' Albany· Bonn. Boston' Cincinnati' Detroit· London' Madrid' Melbourne
Mexico City· Pacific Grove' Paris' San Francisco' Singapore' Tokyo' Toronto' Washington
Art direction: Andrea Meyer, emDASH inc.
Cover design: Saeed Sayrafiezadeh, emDASH inc.
Copyright © 1996
Softcover reprint of the hardcover 2nd edition 1996
Chapman & Hall
For more information, contact:
Chapman & Hall Chapman & Hall
115 Fifth Avenue 2-6 Boundary Row
New York, NY 10003 London SEI 8HN
England
Thomas Nelson Australia
102 Dodds Street Chapman & Hall GmbH
South Melbourne, 3205 Postfach 100 263
Victoria, Australia D-69442 Weinheim
Germany
Nelson Canada
1120 Birchmount Road International Thomson Publishing Asia
Scarborough, Ontario 221 Henderson Road #05-10
Canada, M I K 5G4 Henderson Building
Singapore 0315
International Thomson Editores
Campos Eliseos 385, Piso 7 International Thomson Publishing-Japan
Col. Polanco Hirakawacho-cho Kyowa Building, 3F
11560 Mexico D.F. Mexico 1-2-1 Hirakawacho-cho
Chiyoda-ku, 102 Tokyo
Japan
All rights reserved. No part of this work covered by the copyright hereon may be reproduced or used in any
form or by any means-graphic, electronic, or mechanical, including photocopying, recording, taping, or
information storage and retrieval systems-without the written permission of the publisher.
1234567891OXXXOI 00999796
Library of Congress Cataloging-in-Publication Data
Structural design guide to AISC (LRFD) specification for structural
steel buildings / by Edward S. Hoffman ... [et al.] - 2nd ed.
p. cm.
Includes bibliographical references and index.
ISBN-13: 978-1-4612-8496-3 e-ISBN-13: 978-1-4613-1171-3
DOl: 10.1007/978-1-4613-1171-3
I. Building, Iron and Steel. 2. Structual design. 3. Load
factor design. 4. Steel, structural. I. Hoffman, Edward S.
TA684.S786 1996
691'.7-dc20 96-14942
CIP
British Library Cataloguing in Publication Data available
To order this or any other Chapman & Hall book, please contact International Thomson
Publishing, 7625 Empire Drive, Forence, KY 41042. Phone: [phone]. Fax: [phone].
e-mail: [e-mail].
For a complete listing of Chapman & Hall titles, send your request to Chapman & Hall, Dept. BC,
115 Fifth Avenue, New York, NY 10003.
CONTENTS
I
I
Preface /ix
I-STRUCTURAL MATERIALS AND ECONOMICS:
SPECIFICATIONS, TESTING, AND INSPECTION / 1-13
Materials and Specifications / 1
Testing and Inspection / 8
Economics and the Choice of Materials / 11
2-STRUCTURAL ANALYSIS AND LRFD DESIGN / 15-45
General/l
Pure Flexure / 1
Shear /17
Loads, Load Factors, and Load Combinations /17
Elastic Analysis for One-Story Structures / 18
Elastic Analysis for Multistory Structures / 34
3-BEAMS AND GIRDERS AS FLEXURAL MEMBERS /47-63
Beam Example 1: Simple Span Roof Beam, Simple Framing
Construction / 52
Beam Example 2: Exterior Span Roof Beam, Rigid Frame
(Fully Restrained) Construction / 54
vi CONTENTS
Beam Example 3: Cantilevered Suspended Span, Interior /56
Beam Example 4: Cantilevered Suspended Span, Exterior / 58
Beam Example 5: Simple Spar Office Floor Beam, SF
Construction / 59
Beam Example 6: 5th Floor Exterior Span Floor Beam, FR
(Fully Restrained) Construction for lO-Story Office Building / 63
4-TRUSSES / 65-81
General/65
Design Example 1: Simple Span Welded Roof Truss, Grade 50
Chords and Grade 36 Web.l 66
Design Example 2: Typical Roof Truss Connection, Detail of Top
Chord and Web Members / 75
5-CONNECTIONS / 83-119
General/83
Scope/83
Rivets / 84
Bolts / 85
Welds / 88
Connection Design / 92
Joint Design Examples / 109
6-COLUMNS / 123-145
Definitions / 123
Column Design: Conditions / 125
Slenderness Effects in Axially-Loaded Columns of Braced
Frames /126
Axial Compression and Bendiag / 126
Braced Frames / 129
Axial Compression and Bending with Lateral Forces: Columns in
Unbraced Frames /131
Arbitrary Allowance by Specifications / 133
Individual Column Design / 134
Design Examples Using Specification Formulas with Primary Analy
sis Data / 136
CONTENTS vii
Appendices /147-299
Al. Beam Selection Table / 147
A2. One-Story Rigid Frames / 211
A3. Interior Span of Cantilevered Span System / 233
A4. Exterior Span of Cantilevered Span System / 239
AS. Truss: Continuous Chords, Pinned Diagonals
and Verticals / 245
A6. 5th Floor Gravity Loads: lO-Story Building / 277
A7. lO-Story Office Building: Wind Loads / 285
AISC SPECIFICATION SECTION INDEX / 301
SUBJECT INDEX / 303
PREFACE
I I
This book is intended to guide practicing structural engineers into more
profitable routine designs with the AISC Load and Resistance Factor
Design Specification (LRFD) for structural steel buildings.
LRFD is a method of proportioning steel structures so that no applica
ble limit state is exceeded when the structure is subjected to all appro
priate factored load combinations. Strength limit states are related to
safety, and concern maximum load carrying capacity, Serviceability
limit states are related to performance under service load conditions
such as deflections. The term "resistance" includes both strength states
and serviceability limit states.
LRFD is a new approach to the design of structural steel for buildings.
It involves explicit consideration of limit states, multiple load factors
and resistance factors, and implicit probabilistic determination of relia
bility. The type of factoring used by LRFD differs from the allowable
stress design of Chapters A through M of the 1989 Ninth Edition of the
AISC Specifications for Allowable Stress Design, where only the resistance
is divided by a factor of safety to obtain an allowable stress, and from
the plastic design provisions of Chapter N, where the loads are multi
plied by a common load factor of 1.7 for gravity loads and 1.3 for
gravity loads acting with wind or seismic loads.
LRFD offers the structural engineer greater flexibility, rationality, and
economy than the previous 1989 Ninth Edition of the AISC Specifications
for Allowable Stress Design.
In this book, reference to provisions in the AISC LRFD Specification is
made by parenthetical citations, for example, (Spec. A2.2). Reference to
an Appendix of the Specification is cited with (Appendix BS.3a).
x PREFACE
Artwork for the book was prepared by Jesse Trevino. His skillful
production of the drawings is greatly appreciated by the authors.
The authors are indebted to the late Paul Rice for affording us the
opportunity to continue his concept of a structural design guide. We
trust the format, and most importantly, the contents of this second
edition would meet his expectations. We gratefully dedicate this book to
his memory.
Edward S. Hoffman
David P. Gustafson
Albert J. Gouwens
1
STRUCTURAL MATERIALS
AND ECONOMICS
Specifications, Testing,
and Inspection
MATERIALS AND SPECIFICATIONS
General
Specifications. Structural steel shapes are now available under a vari
ety of specifications and a variety of strength grades within the specifi
cations. Strength grades (minimum specified yield strength in ksi) vary
from 36 to 100. Table 1.1 provides a convenient summary of these
specifications and grades. In addition the various specifications provide
a considerable range in all other properties affecting structural design:
weldability, ductility, corrosion resistance, fatigue resistance, behavior
under different temperatures, and so on (for welding materials, see
Table 1.2).
Availability. The first decision facing the practical engineer responsible
for the design of any steel structure with economy for himself and his
client becomes the selection of the basic material itself. This decision is
an important one, and the sophisticated design flexibility offered by the
possible permutations of the expanded list of material properties, con
nections, and design methods now available makes the choice difficult.
Practical economics of design time required preclude exhaustive cost
comparisons of all such permutations except for unusual projects. Prac
tical economics of construction costs and local immediate availability
simplify this decision for the usual projects. Availability in this sense is
not synonymous with the term as applied in Table 1.1. Table 1.1 should
be regarded merely as the inherent metallurgical limitations upon avail
ability imposed by the manufacturing process. Economic availability
implies material available from several sources (bidders) from stock for
2 STRUCTURAL DESIGN GUIDE
Table 1.1. Availability of Shapes, Plates and Bars According to ASTM
Structural Steel Specifications
ASTM
Specification
Designation Title Grades
Material: SHAPES, PLATES, AND BARS (Spec. A3.1a)
A36 Structural Steel 32 (plate over 8 in. thick)
36 (all other)
A242 High-Strength Low-Alloy Structural Steel 42,46,50
A529 High-Strength Carbon-Manganese Steel 42,50
A572 High-Strength Low-Alloy 42,50,60,65
Columbium-Vanadium Steel
A588 High-Strength Low-Alloy Structural Steel 42,46,50
A709 Structural Steel for Bridges 36,50,70,100
Material: PLATES (Spec. A3.1a)
A514 High-Yield Strength Quenched and 90 and 100
Tempered Alloy Steel
Plate, Suitable for Welding
A852 Quenched and Tempered Low-Alloy 70
Structural Steel Plate
Material: WELDED AND SEAMLESS STEEL PIPE (Spec. A3.1a)
A53 Welded and Seamless Steel Pipe Grade B
Material: WELDED AND SEAMLESS STRUCTURAL STEEL TUBING
(Spec. A3.1 a)
A500 Cold-Formed Welded and Seamless
Carbon Steel Structural
Tubing in Rounds and Shapes
A501 Hot-Formed Welded and Seamless
Carbon Steel Structural Tubing
A618 Hot-Formed Welded and Seamless
High-Strength Low-Alloy
Structural Tubing
Material: STEEL SHEET AND STRIP (Spec. A3.1 a)
A570 Hot-Rolled Carbon Steel Sheets and 40,45,50
Strip, Structural Quality
A606 Steel Sheet and Strip, Hot-Rolled and
Cold-Rolled, High-Strength, Low-Alloy
with Improved Corrosion Resistance
A607 Steel Sheet and Strip, Hot-Rolled and
Cold-Rolled, High-Strength, Low-Alloy,
Columbium and lor Vanadium
Material: STEEL CASTINGS (Spec. A3.2)
A27 Mild-to-Medium Strength Carbon Steel 65-35
Castings for General Applications
A148 High-Strength Steel Castings for 80-50
Structural Purposes
Material: STEEL FORGINGS (Spec. A3.2)
A668 Steel Forgings Carbon and Alloy for
General Industrial Use