LOAD AND RESISTANCE FACTOR DESIGN SPECIFICATION

327 Pages·2001·2.28 MB·English

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
with errata incorporated as of September 4, 2001
Supersedes theLoad and Resistance Factor Design Specification
for Structural Steel Buildingsdated
December 1, 1993 and all previous versions.
Prepared by the
American Institute of Steel 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
ii
Copyright © 2000
by
American Institute of Steel Construction, Inc.
All rights reserved. This book or any part thereof must not be reproduced in any
form without the written permission of the publisher.
Theinformationpresentedinthispublicationhasbeenpreparedinaccordancewith
recognized engineering principles and is for general information only. While it is
believedtobeaccurate,thisinformationshouldnotbeusedorrelieduponforany
specificapplicationwithoutcompetentprofessionalexaminationandverificationof
itsaccuracy,suitability,andapplicabilitybyalicensedengineer,architectorother
professional.Thepublicationofthematerialcontainedhereinisnotintendedasa
representationorwarrantyonthepartoftheAmericanInstituteofSteelConstruc-
tion,Inc.orofanyotherpersonnamedherein,thatthisinformationissuitablefor
anygeneralorparticularuseoroffreedomfrominfringementofanypatentorpat-
ents.Anyonemakinguseofthisinformationassumesallliabilityarisingfromsuch
use.
Cautionmustbeexercisedwhenrelyinguponotherspecificationsandcodesdevel-
opedbyotherbodiesandincorporatedbyreferencehereinsincesuchmaterialmay
bemodifiedoramendedfromtimetotimesubsequenttotheprintingofthisedition.
TheAmericanInstituteofSteelConstruction,Inc.bearsnoresponsibilityforsuch
materialotherthantorefertoitandincorporateitbyreferenceatthetimeofthe
initial publication of this edition.
PrintedintheUnitedStatesofAmerica
LRFD Specification for Structural Steel Buildings, December 27, 1999
AMERICANINSTITUTE OFSTEELCONSTRUCTION
iii
PREFACE
TheAISCLoadandResistanceFactorDesign(LRFD)SpecificationforStructuralSteel
Buildingsisbasedonreliabilitytheory.AshaveallAISCSpecifications,thisSpecifica-
tionhasbeenbaseduponpastsuccessfulusage,advancesinthestateofknowledge,and
changesindesignpractice.ThisSpecificationhasbeendevelopedasaconsensusdocu-
menttoprovideauniformpracticeinthedesignofsteel-framedbuildings.Theintention
istoprovidedesigncriteriaforroutineuseandnottoprovidespecificcriteriaforinfre-
quently encountered problems, which occur in the full range of structural design.
ThisSpecificationistheresultoftheconsensusdeliberationsofacommitteeofstructural
engineerswithwideexperienceandhighprofessionalstanding,representingawidegeo-
graphicaldistributionthroughouttheU.S.Thecommitteeincludesapproximatelyequal
numbers of engineers in private practice and code agencies, engineers involved in
researchandteaching,andengineersemployedbysteelfabricatingandproducingcom-
panies.Thecontributionsandassistanceofmorethan50additionalprofessionalvolun-
teers working in 15 task committees are also hereby acknowledged.
TheSymbols,Glossary,andAppendicestothisSpecificationareanintegralpartofthe
Specification.Anon-mandatoryCommentaryhasbeenpreparedtoprovidebackground
for the Specification provisions and the user is encouraged to consult it.
The principal changes incorporated in this edition of the Specification include:
•Dualunitsformat. ValuesandequationsaregiveninbothU.S.customary
andmetricunits. Themetricconversions(giveninparenthesesfollowing
theU.S.units)arebasedonASTME380,StandardPracticeforUseofthe
InternationalSystemofUnits(SI). Theequationsarenon-dimensionalized
where possible by factoring out material constants, such asEandG.
•Inclusion of new structural steels ASTM A913 and A992.
•Additional notch toughness requirements for complete-joint-penetration
groove welds with tension applied normal to the effective area.
•New provisions for stability bracing of beams, columns, and frames.
•New Chapter N for evaluation of existing structures.
•RevisedprovisionsformemberdesignunderfatigueloadinginAppendix
K.
LRFD Specification for Structural Steel Buildings, December 27, 1999
AMERICANINSTITUTE OFSTEELCONSTRUCTION
iv PREFACE
•Reorganization of material on pin-connected members and eyebars.
•Revised provisions for concrete-encased beams.
•Newlimitationonthestudreductionfactorwhenasinglestudisusedina
rib.
•Revised bolt bearing strength criteria.
Thereaderiscautionedthatprofessionaljudgmentmustbeexercisedwhendataorrecom-
mendations in the Specification are applied, as described more fully in the disclaimer
notice preceding this Preface.
By the Committee,
Stanley D. Lindsey, Chairman Nestor R. Iwankiw
Roger E. Ferch, Vice Chairman Lawrence A. Kloiber
Hansraj G. Ashar Roberto T. Leon
William F. Baker H.S. Lew
John M. Barsom James O. Malley
Reidar Bjorhovde Richard W. Marshall
Roger L. Brockenbrough Harry W. Martin
Wai-Fah Chen William A. Milek
Gregory G. Deierlein Duane K. Miller
Robert O. Disque Thomas M. Murray
Duane S. Ellifritt R. Shankar Nair
Bruce R. Ellingwood Clarkson W. Pinkham
Shu-Jin Fang Douglas D. Rees-Evans
Steven J. Fenves Thomas Z. Scarangello
James M. Fisher Donald R. Sherman
John W. Fisher W. Lee Shoemaker
Theodore V. Galambos Frank F. Sowokinos
Lawrence G. Griffis William A. Thornton
James R. Harris Raymond H. R. Tide
Tony C. Hazel Ivan M. Viest
Mark V. Holland Joseph A. Yura
Cynthia J. Lanz, Secretary
LRFD Specification for Structural Steel Buildings, December 27, 1999
AMERICANINSTITUTE OFSTEELCONSTRUCTION
v
TABLEOFCONTENTS
SYMBOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii
SPECIFICATION
A. GENERAL PROVISIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
A1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
A2. Types of Construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
A3. Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1. Structural Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Steel Castings and Forgings . . . . . . . . . . . . . . . . . . . . . . 4
3. Bolts, Washers, and Nuts. . . . . . . . . . . . . . . . . . . . . . . . 4
4. Anchor Rods and Threaded Rods . . . . . . . . . . . . . . . . . . . 5
5. Filler Metal and Flux for Welding . . . . . . . . . . . . . . . . . . . 5
6. Stud Shear Connectors . . . . . . . . . . . . . . . . . . . . . . . . . 6
A4. Loads and Load Combinations . . . . . . . . . . . . . . . . . . . . . . . 6
A5. Design Basis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Required Strength at Factored Loads. . . . . . . . . . . . . . . . . . 6
2. Limit States. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Design for Strength. . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Design for Serviceability and Other Considerations. . . . . . . . . . 7
A6. Referenced Codes and Standards . . . . . . . . . . . . . . . . . . . . . . 7
A7. Design Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
B. DESIGN REQUIREMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . 10
B1. Gross Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
B2. Net Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
B3. Effective Area of Tension Members. . . . . . . . . . . . . . . . . . . . 10
B4. Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
B5. Local Buckling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1. Classification of Steel Sections . . . . . . . . . . . . . . . . . . . . 12
2. Design by Plastic Analysis . . . . . . . . . . . . . . . . . . . . . . 13
3. Slender-Element Compression Sections . . . . . . . . . . . . . . . 13
B6. Bracing at Supports . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
B7. Limiting Slenderness Ratios. . . . . . . . . . . . . . . . . . . . . . . . 13
B8. Simple Spans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
B9. End Restraint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
B10. Proportions of Beams and Girders. . . . . . . . . . . . . . . . . . . . . 13
C. FRAMES AND OTHER STRUCTURES . . . . . . . . . . . . . . . . . . . 17
C1. Second Order Effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1. Design by Plastic Analysis . . . . . . . . . . . . . . . . . . . . . . 17
2. Design by Elastic Analysis . . . . . . . . . . . . . . . . . . . . . . 17
C2. Frame Stability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1. Braced Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2. Unbraced Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
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vi TABLE OF CONTENTS
SPECIFICATION (Cont’d)
C3. Stability Bracing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2. Frames. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3. Columns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4. Beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
D. TENSION MEMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
D1. Design Tensile Strength . . . . . . . . . . . . . . . . . . . . . . . . . . 24
D2. Built-Up Members. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
D3. Pin-Connected Members and Eyebars. . . . . . . . . . . . . . . . . . . 25
1. Pin-Connected Members . . . . . . . . . . . . . . . . . . . . . . . 25
2. Eyebars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
E. COLUMNS AND OTHER COMPRESSION MEMBERS. . . . . . . . . . 27
E1. Effective Length and Slenderness Limitations. . . . . . . . . . . . . . . 27
1. Effective Length. . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2. Design by Plastic Analysis . . . . . . . . . . . . . . . . . . . . . . 27
E2. Design Compressive Strength for Flexural Buckling . . . . . . . . . . . 27
E3. Design Compressive Strength for Flexural-Torsional Buckling. . . . . . 28
E4. Built-Up Members. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1. Design Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2. Detailing Requirements. . . . . . . . . . . . . . . . . . . . . . . . 29
E5. Connections for Pin-Connected Compression Members. . . . . . . . . . 30
F. BEAMS AND OTHER FLEXURAL MEMBERS . . . . . . . . . . . . . . 31
F1. Design for Flexure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . 32
3. Design by Plastic Analysis . . . . . . . . . . . . . . . . . . . . . . 34
F2. Design for Shear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
1. Web Area Determination . . . . . . . . . . . . . . . . . . . . . . . 35
2. Design Shear Strength. . . . . . . . . . . . . . . . . . . . . . . . . 35
3. Transverse Stiffeners . . . . . . . . . . . . . . . . . . . . . . . . . 36
F3. Web-Tapered Members . . . . . . . . . . . . . . . . . . . . . . . . . . 36
F4. Beams and Girders with Web Openings. . . . . . . . . . . . . . . . . . 36
G. PLATE GIRDERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
H. MEMBERS UNDER COMBINED FORCES AND TORSION . . . . . . . 38
H1. Symmetric Members Subject to Bending and Axial Force . . . . . . . . 38
1. Doubly and Singly Symmetric Members in Flexure and Tension . . 38
2. Doubly and Singly Symmetric Members in Flexure and
Compression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
H2. Unsymmetric Members and Members Under Torsion and
Combined Torsion, Flexure, Shear, and/or Axial Force . . . . . . . . . . 39
H3. Alternative Interaction Equations for Members Under Combined
Stress (see Appendix H3) . . . . . . . . . . . . . . . . . . . . . . . . . 39
I. COMPOSITE MEMBERS. . . . . . . . . . . . . . . . . . . . . . . . . . . 40
I1. Design Assumptions and Definitions . . . . . . . . . . . . . . . . . . . 40
I2. Compression Members. . . . . . . . . . . . . . . . . . . . . . . . . . . 41
1. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
LRFD Specification for Structural Steel Buildings, December 27, 1999
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TABLE OF CONTENTS vii
SPECIFICATION (Cont’d)
2. Design Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3. Columns with Multiple Steel Shapes . . . . . . . . . . . . . . . . . 42
4. Load Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
I3. Flexural Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
1. Effective Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2. Design Strength of Beams with Shear Connectors . . . . . . . . . . 43
3. Design Strength of Concrete-Encased Beams . . . . . . . . . . . . 44
4. Strength During Construction. . . . . . . . . . . . . . . . . . . . . 44
5. Formed Steel Deck . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6. Design Shear Strength. . . . . . . . . . . . . . . . . . . . . . . . . 46
I4. Combined Compression and Flexure . . . . . . . . . . . . . . . . . . . 46
I5. Shear Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
1. Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2. Horizontal Shear Force . . . . . . . . . . . . . . . . . . . . . . . . 46
3. Strength of Stud Shear Connectors . . . . . . . . . . . . . . . . . . 47
4. Strength of Channel Shear Connectors . . . . . . . . . . . . . . . . 47
5. Required Number of Shear Connectors. . . . . . . . . . . . . . . . 47
6. Shear Connector Placement and Spacing. . . . . . . . . . . . . . . 48
I6. Special Cases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
J. CONNECTIONS, JOINTS, AND FASTENERS . . . . . . . . . . . . . . . 49
J1. General Provisions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
1. Design Basis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2. Simple Connections . . . . . . . . . . . . . . . . . . . . . . . . . 49
3. Moment Connections . . . . . . . . . . . . . . . . . . . . . . . . . 49
4. Compression Members with Bearing Joints . . . . . . . . . . . . . 49
5. Splices in Heavy Sections . . . . . . . . . . . . . . . . . . . . . . 49
6. Beam Copes and Weld Access Holes. . . . . . . . . . . . . . . . . 50
7. Minimum Strength of Connections . . . . . . . . . . . . . . . . . . 50
8. Placement of Welds and Bolts . . . . . . . . . . . . . . . . . . . . 51
9. Bolts in Combination with Welds . . . . . . . . . . . . . . . . . . 51
10. High-Strength Bolts in Combination with Rivets. . . . . . . . . . . 51
11. Limitations on Bolted and Welded Connections . . . . . . . . . . . 51
J2. Welds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
1. Groove Welds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
2. Fillet Welds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3. Plug and Slot Welds . . . . . . . . . . . . . . . . . . . . . . . . . 56
4. Design Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5. Combination of Welds. . . . . . . . . . . . . . . . . . . . . . . . . 58
6. Weld Metal Requirements . . . . . . . . . . . . . . . . . . . . . . 58
7. Mixed Weld Metal. . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8. Preheat for Heavy Shapes. . . . . . . . . . . . . . . . . . . . . . . 58
J3. Bolts and Threaded Parts. . . . . . . . . . . . . . . . . . . . . . . . . . 58
1. High-Strength Bolts. . . . . . . . . . . . . . . . . . . . . . . . . . 58
2. Size and Use of Holes . . . . . . . . . . . . . . . . . . . . . . . . 59
3. Minimum Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4. Minimum Edge Distance. . . . . . . . . . . . . . . . . . . . . . . 60
5. Maximum Spacing and Edge Distance . . . . . . . . . . . . . . . . 60
6. Design Tension or Shear Strength . . . . . . . . . . . . . . . . . . 62
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viii TABLE OF CONTENTS
SPECIFICATION (Cont’d)
7. Combined Tension and Shear in Bearing-Type Connections. . . . . 63
8. High-Strength Bolts in Slip-Critical Connections . . . . . . . . . . 64
9. Combined Tension and Shear in Slip-Critical Connections . . . . . 66
10. Bearing Strength at Bolt Holes . . . . . . . . . . . . . . . . . . . . 66
11. Long Grips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
J4. Design Rupture Strength. . . . . . . . . . . . . . . . . . . . . . . . . . 67
1. Shear Rupture Strength . . . . . . . . . . . . . . . . . . . . . . . . 67
2. Tension Rupture Strength. . . . . . . . . . . . . . . . . . . . . . . 67
3. Block Shear Rupture Strength. . . . . . . . . . . . . . . . . . . . . 67
J5. Connecting Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
1. Eccentric Connections. . . . . . . . . . . . . . . . . . . . . . . . . 68
2. Design Strength of Connecting Elements in Tension. . . . . . . . . 68
3. Other Connecting Elements. . . . . . . . . . . . . . . . . . . . . . 68
J6. Fillers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
J7. Splices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
J8. Bearing Strength. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
J9. Column Bases and Bearing on Concrete. . . . . . . . . . . . . . . . . . 70
J10. Anchor Rods and Embedments . . . . . . . . . . . . . . . . . . . . . . 70
K. CONCENTRATED FORCES, PONDING, AND FATIGUE. . . . . . . . . 71
K1. Flanges and Webs with Concentrated Forces . . . . . . . . . . . . . . . 71
1. Design Basis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
2. Flange Local Bending . . . . . . . . . . . . . . . . . . . . . . . . 71
3. Web Local Yielding. . . . . . . . . . . . . . . . . . . . . . . . . . 72
4. Web Crippling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5. Web Sidesway Buckling. . . . . . . . . . . . . . . . . . . . . . . . 73
6. Web Compression Buckling . . . . . . . . . . . . . . . . . . . . . 74
7. Web Panel-Zone Shear . . . . . . . . . . . . . . . . . . . . . . . . 75
8. Unframed Ends of Beams and Girders. . . . . . . . . . . . . . . . 76
9. Additional Stiffener Requirements for Concentrated Forces . . . . . 76
10. Additional Doubler Plate Requirements for Concentrated Forces . . 76
K2. Ponding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
K3. Design for Cyclic Loading (Fatigue). . . . . . . . . . . . . . . . . . . . 77
L. SERVICEABILITY DESIGN CONSIDERATIONS. . . . . . . . . . . . . 79
L1. Camber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
L2. Expansion and Contraction . . . . . . . . . . . . . . . . . . . . . . . . 79
L3. Deflections, Vibration, and Drift . . . . . . . . . . . . . . . . . . . . . 79
1. Deflections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
2. Floor Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
3. Drift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
L4. Connection Slip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
L5. Corrosion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
M. FABRICATION, ERECTION, AND QUALITY CONTROL . . . . . . . . 81
M1. Shop Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
M2. Fabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
1. Cambering, Curving, and Straightening . . . . . . . . . . . . . . . 81
2. Thermal Cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
3. Planing of Edges . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
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SPECIFICATION (Cont’d)
4. Welded Construction . . . . . . . . . . . . . . . . . . . . . . . . . 82
5. Bolted Construction . . . . . . . . . . . . . . . . . . . . . . . . . 82
6. Compression Joints . . . . . . . . . . . . . . . . . . . . . . . . . . 82
7. Dimensional Tolerances. . . . . . . . . . . . . . . . . . . . . . . . 82
8. Finish of Column Bases. . . . . . . . . . . . . . . . . . . . . . . . 82
M3. Shop Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
1. General Requirements . . . . . . . . . . . . . . . . . . . . . . . . 83
2. Inaccessible Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . 83
3. Contact Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
4. Finished Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
5. Surfaces Adjacent to Field Welds . . . . . . . . . . . . . . . . . . 83
M4. Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
1. Alignment of Column Bases . . . . . . . . . . . . . . . . . . . . . 83
2. Bracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
3. Alignment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4. Fit of Column Compression Joints and Base Plates . . . . . . . . . 84
5. Field Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
6. Field Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
7. Field Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . 84
M5. Quality Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
1. Cooperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
2. Rejections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
3. Inspection of Welding . . . . . . . . . . . . . . . . . . . . . . . . 85
4. Inspection of Slip-Critical High-Strength BoltedConnections. . . . 85
5. Identification of Steel . . . . . . . . . . . . . . . . . . . . . . . . . 85
N. EVALUATION OF EXISTING STRUCTURES . . . . . . . . . . . . . . . 86
N1. General Provisions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
N2. Material Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
1. Determination of Required Tests . . . . . . . . . . . . . . . . . . . 86
2. Tensile Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
3. Chemical Composition . . . . . . . . . . . . . . . . . . . . . . . . 86
4. Base Metal Notch Toughness . . . . . . . . . . . . . . . . . . . . . 87
5. Weld Metal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6. Bolts and Rivets. . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
N3. Evaluation by Structural Analysis . . . . . . . . . . . . . . . . . . . . . 87
1. Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2. Strength Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . 87
3. Serviceability Evaluation . . . . . . . . . . . . . . . . . . . . . . . 87
N4. Evaluation by Load Tests . . . . . . . . . . . . . . . . . . . . . . . . . 88
1. Determination of Live Load Rating by Testing. . . . . . . . . . . . 88
2. Serviceability Evaluation . . . . . . . . . . . . . . . . . . . . . . . 88
N5. Evaluation Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
APPENDIX B. DESIGN REQUIREMENTS . . . . . . . . . . . . . . . . . . . 89
B5. Local Buckling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
1. Classification of Steel Sections. . . . . . . . . . . . . . . . . . . . 89
3. Slender-Element Compression Sections . . . . . . . . . . . . . . . 89
APPENDIX E. COLUMNS AND OTHER COMPRESSION MEMBERS . . . 94
LRFD Specification for Structural Steel Buildings, December 27, 1999
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