Anteproyecto uniones calificadas AISC

DRAFT

Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic

Applications

April 23, 2004

ii

Draft

This document has been produced as a working draft as part of the American Institute of Steel Construction’s efforts to develop a Standard for the design of moment-resisting connections for use in frames designed to resist seismic forces through inelastic response. The purpose of this draft is to permit review and development by the Standards Committee as well as comment by prospective users of the Standard prior to eventual adoption and publication. Although portions of the document must necessarily appear in the form of an actual Standard, it is not intended to serve as such until formally adopted through the AISC consensus process. Information contained in this document may be incomplete and in some cases, erroneous or otherwise incorrect. Information presented herein should not be used as the basis for engineering projects and decisions, nor should it be disseminated or attributed.

iii

Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications

American Institute of Steel Construction

Connections Prequalification Review Panel

Committee Members Designers Ron Hamburger [email protected] (Chairman) Nathan Charlton [email protected] Larry Novak [email protected] Bob Lyons [email protected] Kevin Moore [email protected] Tom Sabol [email protected] Industry Pat Hassett [email protected] Fred Breismeister [email protected] Keith Landwehr [email protected] Mike Mayes [email protected] Duane Miller [email protected] Brett Manning [email protected]

General Interest

Ted Droessler [email protected] Mike Engelhardt [email protected]. Linda Hanagan [email protected] Bob Shaw [email protected] Chris Tokas [email protected] Ben Yousefi [email protected] Tom Murray [email protected] Corresponding

Hank Martin [email protected] Roberto Leon [email protected] Jim Malley [email protected] Tom Schlafly [email protected] Emmett Sumner [email protected] Chia-Mina Uang [email protected] Lanny Flynn [email protected]

Chris Hewitt [email protected] (Secretary)

DRAFT

Draft April 23, 2004

1

TABLE OF CONTENTS

i. Symbols ii. Glossary 1. General 2. Design Criteria 3. Welding Requirements 4. Bolting Requirements 5. Reduced Beam Section (RBS) Moment Connection 6. Bolted Unstiffened and Stiffened Extended End-Plate Moment Connections Appendix N. Nondestructive Testing Appendix Q. Quality Assurance Plan Requirements Appendix Y. Visual Inspection

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I. SYMBOLS Numbers in parentheses after the definition of a symbol refer to the Section of this Standard in which the symbol is first used.

Ab Nominal gross area of bolt, in2 (mm2)

An Net area, in2 (mm2)

Cpr a factor to account for the peak connection strength, including strain hardening, local restraint, additional reinforcement, and other connection conditions, as given in Equation 2.4.3-2

Ct Factor used in Equation 6.24

Ffu Ultimate Flange Force, kips (N)

Fsu Ultimate Stiffener Force, kips (N)

Fu Specified minimum tensile strength, ksi (MPa)

Fup Minimum tensile strength of the end plate, ksi (MPa)

Fv Nominal shear strength of bolts, ksi (MPa)

Fy Specified minimum yield stress of the type of steel to be used, ksi (MPa). As used in the LRFD Specification, "yield stress" denotes either the minimum specified yield point (for those steels that have a yield point) or the specified yield strength (for those steels that do not have a yield point), ksi (MPa)

Fyb Fy of a beam, ksi (MPa)

Fyc Fy of a column, ksi (MPa)

Fyp Fy of end plate material, ksi (MPa)

Fys Fy of stiffener material, ksi (MPa)

L’ Distance between centers of RBS cuts, in. (mm)

Lc Clear distance in the direction of force, in. (mm)

Lst Length of the end plate stiffener, in. (mm)

Mf Maximum moment expected at face of column, kip-in (N-mm)

Mnp No prying bolt moment strength, kip-in (N-mm)

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Mpe Plastic moment of beam based on expected yield strength, kip-in (N-mm)

Mpr Probable maximum moment at plastic hinge, kip-in (N-mm)

MRBS Maximum moment expected at center of RBS, kip-in (N-mm)

Muc Moment at the face of the column, kip-in (N-mm)

N Thickness of beam flange plus 2 times the groove weld reinforcement leg size, in. (mm)

Pt Bolt tensile strength, kips (N)

Rn The required force for stiffener design, kips (N).

Ry Ratio of the Expected Yield Strength to the minimum specified yield strength Fy

Rvb Ratio of the Expected Yield Strength to the minimum specified yield strength Fy, for a beam

Rvc Ratio of the Expected Yield Strength to the minimum specified yield strength Fy, for a column

Vgravity Beam shear force resulting from 1.2D + 0.5L + 0.2S, kips (N)

VRBS Larger of the two values of shear force at the centers of the RBS cuts at each end of the beam, kips (N)

V’RBS Smaller of the two values of shear force at the centers of the RBS cuts at each end of the beam, kips (N)

Vu Required shear strength of a member, kips (N)

Yc Unstiffened column flange yield line mechanism parameter

Yp The end plate yield line mechanism parameter from Table 7.2, 7.3, or 7.4.

Z Plastic section modulus of a member, in.3 (mm3)

Zb Plastic section modulus of the beam, in.3 (mm3)

Ze The effective plastic modulus of the section (or connection) at the location of the plastic hinge, in.3 (mm3)

ZRBS Plastic section modulus at minimum section of RBS, in.3 (mm3)

a Horizontal distance between a column flange and the start of an RBS cut, in. (mm)

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b Width of compression element as defined in the AISC Specification, in. (mm)

Length of an RBS cut, in. (mm)

bf Flange width, in. (mm)

bp Width of plate, in. (mm)

c Width of an RBS cut, in. (mm)

d Depth, in. (mm)

db Req’d Required bolt diameter, in. (mm)

dc Depth of column, in. (mm)

g Horizontal gage between bolts, in.(mm)

h Clear distance between flanges less the fillet or corner radius for rolled shapes; Clear distance between flanges when welds are used for built-up shapes; Distance from the centerline of the compression flange to the tension side edge of the end-plate in an end-plate connection, in.(mm)

hi Distance from the centerline of the beam compression flange to the centerline of the ith tension bolt row, in.(mm)

h1 Distance from the centerline of the compression flange to the tension side inner bolt row in the 4E and 4ES connections, in.(mm)

hi Distance from centerline of the compression flange to a tension bolt row to the centerline of the ith bolt row, in.(mm)

ho Distance from the centerline of the compression flange to the tension side outer bolt row in the 4E and 4ES connections, in.(mm)

hst Height of the stiffener, in. (mm)

kc Distance from outer face of the column flange to web toe of fillet (design value) , in.(mm)

nb Number of bolts at the compression flange

ni Number of inner bolts

no Number of outer bolts

pb Pitch between the inner and outer row of bolts in an eight bolt connection, in.(mm)

pf Vertical distance between beam flange and the nearest row of bolts, in. (mm)

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pfi Distance from inside of the beam tension flange to the nearest inside bolt row, in.(mm)

pfo Distance from outside of the beam tension flange to the nearest outside bolt row, in.(mm)

psi Distance from the inside face of column stiffener to the nearest inside bolt row, in.(mm)

pso Distance from the outside face of column stiffener to the nearest outside bolt row, in.(mm)

s Distance from the centerline of the most inside or most outside tension bolt row to the edge of the yield line pattern, in.(mm)

sh Distance from the face of the column to the plastic hinge, in.(mm)

t Thickness of connected part, in. (mm)

Thickness of element, in. (mm)

tbf Thickness of beam flange, in. (mm)

tcf Thickness of column flange, in. (mm)

tf Thickness of flange, in. (mm)

tp Thickness of Plate or Panel Zone including doubler plates, in. (mm)

twb Thickness of beam web, in. (mm)

w Uniform Beam Gravity Load, kips per linear ft (N per linear mm)

φ Resistance Factor

φn Resistance Factor for non-ductile limit states

φd Resistance Factor for ductile limit states

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II. Glossary

The first letter(s) of words or terms that appear in this glossary are generally capitalized throughout this Standard. This glossary does not contain common steel design terms, as defined in the 2005 AISC Specification for Structural Steel Buildings.

Applicable Building Code. The building code under which the building is designed. In the absence of an Applicable Building Code, the loads and load combinations shall be those stipulated in ASCE 7.

Amplified Seismic Load. The horizontal component of earthquake load E multiplied by Ωo, where E and the horizontal component of E are defined in the Applicable Building Code.

Associate Welding Inspector (AWI). A person meeting the qualification requirements of AWS B5.1 Section 3.1.

Backing. A piece of metal or other material, placed at the weld root to facilitate placement of the root pass.

Backgouge. The process of removing by grinding or air carbon arc cutting the all or a portion of the root pass of a complete joint penetration groove weld, form the reverse side of the joint from which the root pass was originally placed.

Carbon Arc Cutting. A process of cutting steel by the heat from an electric arc applied simultaneously with an air jet.

Column Base. The assemblage of plates, connectors, bolts, and rods at the base of a column used to transmit forces between the steel superstructure and the foundation.

Continuity Plates. Column stiffeners at the top and bottom of the Panel Zone; also known as transverse stiffeners.

Contractor. Steel Fabricator or Erector, as applicable.

Certificates of Conformance. A written representation by the supplier of material that the material conforms in all respects to the requirements of the specifications.

Demand Critical Weld. A welded joint that under design conditions is subjected to yield level stresses.

Design Strength. Resistance (force, moment, stress, as appropriate) provided by element or connection; the product of the Nominal Strength and the Resistance Factor.

Dye Penetrant Testing. A method of nondestructive testing to detect weld cracks and defects that are open to the weld surface through the application of a pigmented dye to the weldment.

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Expected Yield Strength. The probable yield strength of the material, equal to the minimum specified yield strength, Fy, multiplied by Ry .

Fully Restrained (FR). Sufficient rigidity exists in the connection to maintain the angles between intersecting members.

Intermediate Moment Frame (IMF). A Moment Frame system that meets the requirements in Section 10 of the AISC Seismic Provisions.

Interpass Temperature. The temperature of a steel joint during a multi-pass welding procedure following the placement of one weld pass and just prior to placement of the next weld pass.

Non-fusible Backing. A backing material that will not fuse with the base metals during the welding process.

k-Area. An area of potentially reduced notch-toughness located in the web-to-flange fillet area. See Figure C-I-6.1 of the AISC Seismic Provisions.

Lateral Bracing Member. A member that is designed to inhibit lateral buckling or lateral-tor-sional buckling of primary framing members.

Lowest Anticipated Service Temperature. The lowest temperature that an exposed structure is anticipated to experience simultaneous with application of design loading.

Magnetic Particle Testing (MT). A method of nondestructive testing to detect near surface defects in weldments through the formation of characteristic patterns in iron particles applied to the weld in the presence of a magnetic flux.

Moment Frame. A building frame system in which seismic shear forces are resisted by shear and flexure in members and connections of the frame.

Moment-Resisting Connection. A connection between a beam and column that will develop flexural stresses in each when a differential angular rotation is applied to the assembly.

Non-destructive Testing. A method of investigating the presence of defects in a weldment without causing physical damage to the weldment. Methods include liquid dye penetrant testing (PT), magnetic particle testing (MT), ultrasonic testing (UT) and Radiographic Testing (RT).

Nominal Strength. The capacity of a building or component to resist the effects of loads, as determined by computations using specified material strengths and dimensions and formulas derived from accepted principles of structural mechanics or by field tests or laboratory tests of scaled models, allowing for modeling effects and differences between laboratory and field conditions.

Panel Zone. The web area of the beam-to-column connection delineated by the extension of beam and column flanges through the connection.

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Partially Restrained (PR). A connection with insufficient rigidity to maintain the angles between connected members in original alignment after load is applied.

Plastic Hinge Location. The location in a beam column assembly where inelastic energy dissipation is assumed to occur through the development of plastic flexural straining.

Prequalified Connections. Connections that comply with the requirements of Appendix P.

Probable Plastic Moment. The expected moment developed at a plastic hinge location, considering the probable (mean) value of the material strength for the specified steel and effects of strain hardening.

Protected Zone. The hinging area of beams in which limitations apply to fabrication and attachments.

Quality Assurance (QA). Those inspection services to be performed by an agency of firm other than the Contractor.

Quality Assurance Plan. Written description of qualifications, procedures, quality inspections, resources and records to be used to provide assurance that the structure complies with the Engineer's quality requirements, specifications and contract documents.

Quality Control (QC). Those functions to be performed by the Contractor to ensure that the material and workmanship of construction meet the quality requirements.

Reduced Beam Section. A reduction in cross section over a discrete length that promotes a zone of inelasticity in the member.

Reinforcing Fillet. A fillet weld applied to a groove welded “tee-joint” to obtain increased weld strength and a smoothed contour to reduce stress concentrations associated with joint geometry.

Required Strength. The load effect (force, moment, stress, or as appropriate) acting on a member or connection that is determined by structural analysis from the factored loads using the most appropriate critical load combinations, or as specified in this Standard.

Root Pass. That portion of a multi-pass weld deposited in the first pass of welding.

Seismic Load Resisting System. The assembly of structural elements in the building that resists seismic loads, including struts, collectors, chords, diaphragms and trusses.

Senior Welding Inspector (SWI). A person meeting the qualification requirements of AWS B5.1 Section 3.3.

Special Moment Frame (SMF). A Moment Frame system that meets the requirements in Section 9 of the AISC Seismic Provisions.

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Thermal Cutting. The process of cutting steel through local heating to the melting temperature of the material.

Ultrasonic Testing. A method of nondestructive testing to detecting embedded defects in a weldemnt by passing high frequency sound waves through the weldment and detecting the time required to receive a reflection of these sound waves.

Visual Welding Inspection. A method of welding inspection that includes visual observation of the preparation and process of welding and the visually apparent condition of the completed joint.

Weld Tab. A piece of metal affixed to the end of a welded joint to facilitate the initiation and termination of weld passes outside the structural joint.

Welding Inspector (WI) – A person meeting the qualification requirements of AWS B5.1 Section 3.2.

Welding Personnel Qualification Records (WPQR). Written documentation of the ability of a particular welding procedure specification to produce welds of the required strength and toughness.

Welding Procedure Specification (WPS). A written specification of the preparation, materials, electrical and workmanship requirements by which a welded joint is to be made.

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1. GENERAL 1

1.1 Scope 2

This Standard specifies design, detailing, fabrication and quality criteria for connections that are 3 prequalified in accordance with the AISC Seismic Provisions for Structural Steel Buildings 4 (herein called the AISC Seismic Provisions) for use with Special and Intermediate Moment 5 Frames. The connections contained in this Standard are Prequalified to meet the criteria in the 6 AISC Seismic Provisions only when designed and constructed in accordance with the 7 requirements of this Standard. Nothing in this Standard shall preclude the use of connection 8 types contained herein outside the indicated limitations, or the use of other connection types, 9 when satisfactory evidence of qualification in accordance with Appendix S of the AISC Seismic 10 Provisions is presented to the Authority Having Jurisdiction. 11

1.2 References 12

The following standards form a part of this Standard to the extent that they are referenced and 13 applicable: 14

2005 AISC Seismic Provisions for Structural Steel Buildings 15

2004 AWS D1.1 Structural Welding Code – Steel (herein called AWS D1.1) 16

2000 RCSC Specification for Structural Joints using ASTM 325 or A490 Bolts (herein called 17 the RCSC Specification) 18

2005 AISC Specification for Structural Steel Buildings (herein called the AISC 19 Specification) 20

1.3 General 21

All design, materials, and workmanship shall conform to the requirements of the AISC Seismic 22 Provisions, unless modified herein. 23

24

25

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2. DESIGN CRITERIA 1

2.1 Special and Intermediate Moment-Resisting Frame Connection Types 2

The connection types listed in Table 2-1 are Prequalified for use in connecting beams to column 3 flanges in Special and Intermediate Moment Frames within the tabulated limitations and the 4 other limitations specified in this Standard. 5

6

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2-2

Table 2-1 Prequalified Moment-Resisting Connections 6

* Prequalified only for SMFs not supporting structural concrete slabs. 7

8

Intermediate Moment-Resisting Connections

Special Moment-Resisting Connections

Designation Property Limitation Limitation

Beam depth W36 or shallower W36 or shallower

Beam Flange thickness

1-3/4 in. (45 mm) or less 1-3/4 in. (45 mm) or less

Beam Weight 300 lbs (136 kg) per foot or less 300 (136 kg) pounds per foot or less

Beam Span to depth ratio

5 or greater 7 or greater

Reduced Beam Section (RBS)

Column Profile W36 or shallower.

Built-up box 36 in. (0.9 m) deep by 24 in. (0.6 m) wide or shallower, except

biaxially loaded columns which are limited to 24in.(0.6 m) by 24 in.(0.6 m) or

shallower

Boxed wide flange section W36 or shallower

Cruciform W-shapes 36 in. (0.9 m) or shallower

W36 or shallower.

Built-up box 36 in. (0.9 m) deep by 24 in. (0.6 m) wide or shallower, except

biaxially loaded columns which are limited to 24in.(0.6 m) by 24 in.(0.6 m) or

shallower

Boxed wide flange section W36 or shallower

Cruciform W-shapes 36 in. (0.9 m) or shallower

Beam depth W14 – 55 in. Built-up section

W14 – 55 in. Built-up section*


3/8 – ¾ in. (10 -19 mm) 3/8 – ¾ in. (10-19 mm)*


5 or greater 7 or greater

Bolted Unstiffened End -Plate (BUEP)

Column depth Column can be no deeper than the beam Column can be no deeper than the beam

Beam depth W14 -W36 W14 -W36*


0.375 – 1.00 in (10-25 mm) 0.375 – 1.00 in (10-25 mm)*


5 or greater 7 or greater*

Bolted Stiffened End-Plate (BSEP)

Column depth Column can be no deeper than the beam Column can be no deeper than the beam*

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2.2 Connection Stiffness 9

All connections contained in this Standard shall be considered fully restrained (Type FR) for the 10 purpose of analysis. 11

2.3 Members 12

The connections contained in this Standard are Prequalified in accordance with the requirements 13 of the AISC Seismic Provisions when used to connect members meeting the limitations of 14 Sections 2.3.1 or 2.3.2. 15

2.3.1 Hot Rolled Wide Flange Members 16

Hot rolled wide flange members conforming to the cross section profile limitations indicated in 17 Table 2-1 for Special Moment-Resisting Frames or Intermediate Moment-Resisting Frames shall 18 be permitted. 19

2.3.2 Built-up H Section Members 20

Built-up members having a bisymmetric H-shaped cross section with flanges and webs having 21 width, depth, and thickness profiles similar to hot rolled wide flange sections meeting the 22 limitations of Table 2-1 shall be permitted to be used for beams or columns providing that webs 23 are continuously connected and the connections shall comply with the requirements of Sections 24 2.3.2.1 and 2.3.2.2, as applicable. 25

2.3.2.1 Built-up Beams 26

Within a zone extending from the beam end to a distance not less than one beam depth beyond 27 the Plastic Hinge Location, sh, unless otherwise noted, the web and flanges shall be connected 28 using CJP groove welds with a pair of reinforcing fillet welds. Minimum size of fillet welds shall 29 be the lesser of 5/16 in. (8 mm) or the thickness of the beam web. 30

Exception: Where individual connection prequalifications allow other requirements, this 31 provision need not apply. 32

2.3.2.2 Built-up Columns 33

Built-up columns shall conform to the provisions of Section 2.3.2.2.1, 2.3.2.2.2, 2.3.2.2.3 or 34 2.3.2.2.4. Built-up columns shall satisfy the requirements of AISC Specification Section E5 35 except as modified in this section. Transfer of all internal and external forces and stresses shall 36 be through welding. 37

2.3.2.2.1 I-Shaped Welded Columns 38

The elements of built-up I-shaped columns shall conform to Table I-8-1 of the AISC Seismic 39 Provisions. 40

41

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Within a zone extending a distance 12 in. (0.30 m) above and 12 in. (0.30 m) below the panel 42 zone, unless otherwise noted, the column web and flanges shall be connected using CJP groove 43 welds with a pair of reinforcing fillet welds. Minimum size of fillet welds shall be the lesser of 44 5/16 in. or the thickness of the column web. In zones of potential plastic hinging, the weld shall 45 be sufficient to develop the strength of the column web. 46

2.3.2.2.2 Boxed Wide Flange Columns 47

The wide-flanged shape of a Boxed Wide Flange Column shall conform to Table I-8-1 of the 48 AISC Seismic Provisions. 49

The width-to-thickness ratio (b/t) of plates used as flanges shall not exceed 0.6 s

y

EF

where b 50

shall be taken as not less than the clear distance between plates. 51

The width-to-thickness ratio (h/tw) of plates used only as webs shall conform to the provisions of 52 Table I-8-1 of the AISC Seismic Provisions. 53

Within a zone extending from 12 in. (0.30 m) above the upper beam flange to 12 in. (0.30 m) 54 below the lower beam flange, flange and web plates of boxed wide flange columns shall be 55 joined by complete joint penetration groove welds. Outside this zone, boxed wide flange column 56 web and flange plates shall be continuously connected by fillet or groove welds. Continuity 57 plates, if provided shall be connected to the flanges of box columns with complete joint 58 penetration groove welds. Continuity plates shall be connected to the web or webs by either fillet 59 welds or groove welds sufficient to develop the strength of the beam flanges or the strength of 60 the contact area of the continuity plate with the column flanges. 61

2.3.2.2.3 Built-up Box Columns 62

The width-to-thickness ratio (b/t) of plates used as flanges shall not exceed 0.6 s

y

EF

where b 63

shall be taken as not less than the clear distance between plates. 64

The width-to-thickness ratio (h/tw) of plates used only as webs shall conform to the provisions of 65 Table I-8-1 of the AISC Seismic Provisions. 66

Within a zone extending from 12 in. (0.30 m) above the upper beam flange to 12 in. (0.30 m) 67 below the lower beam flange, flange and web plates of box columns shall be joined by complete 68 joint penetration groove welds. Outside this zone, box column web and flange plates shall be 69 continuously connected by fillet welds or groove welds. Continuity plates shall be connected to 70 the flanges of box columns with complete joint penetration groove welds. Continuity plates 71 shall be connected to the webs by either fillet welds or groove welds sufficient to develop the 72 strength of the beam flanges or the strength of the contact area of the continuity plate with the 73 column flanges. 74

2.3.2.2.4 Cruciform W-Shaped Columns 75

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Webs and Flanges of Cruciform W-Shaped Columns shall conform to the requirements of 76 Section 2.3.2.2.1. 77

User Note: For cruciform W-Shaped columns, the provisions of AISC Specification Section E7 78 must be considered. 79

Within a zone extending from 12 in. (0.30 m) above the upper beam flange to 12 in. (0.30 m) 80 below the lower beam flange, the web of the cut wide flange section shall be welded to the web 81 of the continuous wide flange section with complete joint penetration groove welds with a pair 82 of reinforcing fillet welds. Minimum size of fillet welds shall be the lesser of 5/16in. (8mm) or 83 the thickness of the column web. Continuity plates shall conform to the requirements for wide 84 flange columns. 85

2.4 Connection Design Parameters 86

2.4.1 Load Combinations and Resistance Factors 87

Where design procedures contained in this Standard require that loading due to earthquake-88 induced yielding of a connection assembly be applied simultaneously with gravity loading, the 89 applicable load combinations of the AISC Seismic Provisions apply. 90

Where resistances are calculated in accordance with the AISC Specification for Structural Steel 91 Buildings, the resistance factors specified therein shall apply. When resistances are calculated in 92 accordance with this document, the following resistance factors apply: 93

φd = 1.0 94

φn = 0.9 95

2.4.2 Plastic Hinge Location 96

The distance of the plastic hinge, sh, from the face of the column, shall be taken in accordance 97 with the criteria for the individual connection as specified herein. 98

2.4.3 Probable Plastic Moment 99 The probable plastic moment at the location of the plastic hinge shall be taken as: 100

yeyprpr FZRCM = (2.4.3-1) 101

102

where: 103

104

Mpr = probable peak plastic hinge moment 105

Ry = Ratio of the Expected Yield Strength to the minimum specified yield strength Fy 106

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Ze = The effective plastic modulus of the section (or connection) at the location of the plastic 107 hinge, in.3 (mm)3 108

Cpr = a factor to account for the peak connection strength, including strain hardening, local 109 restraint, additional reinforcement, and other connection conditions. Unless otherwise 110 specifically indicated in this standard, the value of Cpr shall be as given by the formula: 111

1.22y u

pry

F + FC

F= ≤ (2.4.3-2) 112

where: 113

Fy = Specified minimum yield stress of the type of steel to be used in the yielding element, ksi 114 (Mpa) 115

Fu = Specified minimum tensile strength of the type of steel to be used in the yielding element, 116 ksi (MPa) 117

2.4.4 Beam Flange Continuity Plates 118

Continuity plates shall be provided. 119

Exception: 120

A. For Bolted End-Plate Connections, the provisions of Section 6 shall apply. 121

B. When the beam flange connects to the flange of a wide-flange or built-up I-shape column 122 having a thickness that satisfies Equations 2.4.4-1 and 2.4.4-2, continuity plates need not be 123 provided: 124

0.4 1.8 yb ybcf f f

yc yc

F Rt b t

F R≥ (2.4.4-1) 125

6

fcf

bt ≥ (2.4.4-2) 126

where: 127

tcf = minimum required thickness of column flange when no continuity 128 plates are provided, in. (mm) 129

bf = beam flange width, in. (mm) 130

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tf = beam flange thickness, in. (mm) 131

Fyb (Fyc) = minimum specified yield stress of the beam (column) flange 132

Ryb (Ryc) = ratio of the expected yield stress of the beam (column) material to 133 the minimum specified yield strength, per the AISC Seismic 134 Provisions. 135

C. When the beam flange connects to the flange of a boxed wide-flange column having a 136 thickness that satisfies Equations 2.4.4-3 and 2.4.4-4, continuity plates need not be provided: 137

20.4 1- ( - ) 1.8 4

fb fb yb ybcf fc f f

yc ycfc

b b F Rt b b t

b F R

≥

(2.4.4-3) 138

12

fcf

bt ≥ (2.4.4-4) 139

2.4.4.1 Continuity Plate Thickness 140

Where continuity plates are required, the thickness of the plates shall be determined as follows: 141

a. For one-sided (exterior) connections, continuity plate thickness shall be at least 142 one-half of the thickness of the beam flange. 143

b. For two-sided (interior) connections, the continuity plate thickness shall be at 144 least equal to the thicker of the two beam flanges on either side of the column. 145

c. Continuity plates shall also conform to the requirements of Section J11.8 of the 146 AISC Specification. 147

2.4.4.2 Continuity Plate to Column Attachment 148 149 Continuity plates shall be welded to column flanges using complete joint penetration groove 150 welds. The Required Strength of these joints shall not be less than the Design Strength of the 151 contact area of the plate with the column flange. The Required Strength of the welded joints of 152 the Continuity Plates to the column web shall be the least of the following: 153

a. The sum of the Design Strengths at the connections of the continuity plate to the 154 column flanges. 155

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b. The design shear strength of the contact area of the plate with the column web. 156

c. The weld Design Strength that develops the design shear strength of the column 157 Panel Zone. 158

d. The actual force transmitted by the stiffener. 159

2.5 Panel Zones 160

Panel Zones shall conform to the minimum requirements for SMF or IMF, as applicable, in 161 Section 9.3 or Section 10.3 of the AISC Seismic Provisions. References to matching of tested 162 connections shall not apply. 163

2.6 Protected Zone 164

Welded shear studs, or other welded, shot-in, bolted or screwed attachments shall not be located 165 within the hinging area of beams, herein defined as the protected zone. The protected zone shall 166 be as specified for the individual connection. 167

168

169

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3-1

3. WELDING REQUIREMENTS 1 2 3.1 Filler metals. 3 4 3.1.1 Mechanical Properties 5 6 3.1.1.1 Notch Toughness 7 8 All welds shall be made with filler metals classified as having a CVN toughness of 20 ft-lbf (27 9 Joules) or higher, tested at -20oF (-29oC) or lower, as determined using the appropriate AWS A5 10 classification test method. 11 12 3.1.1.2 Demand Critical Welds 13 14 Welds designated as Demand Critical shall be made with filler metals tested in accordance with 15 Appendix X of the AISC Seismic Provisions. Filler metals tested in accordance with this 16 requirement shall meet the minimum mechanical requirements of Table 3.1. 17 18 Exception: Supplemental testing in accordance with Appendix X need not be performed for 19 SMAW or GMAW with solid electrodes. 20 21 Table 3.1: Minimum Mechanical Requirements for Demand Critical Welds 22 23 Filler Metal Classification Property

70 ksi (485 MPa)

80 ksi (550 MPa)

Yield Strength, ksi (MPa)

58 (400)

68 (470)

Tensile Strength, ksi (MPa)

70 (485)

80 (550)

Elongation, %

22

19

CVN Toughness, ft-lbf (Joule)

40 @ 70oF*

(54 @ 21oC)*

40 @ 70oF*

(54 @ 21oC)* *For applications where the Seismic Load Resisting System is subjected to service temperatures below 50oF (10oC) following completion 24 of the structure, the minimum CVN of 40 ft-lbf (54 Joules) shall be provided at a test temperature not more than 20o F (11oC) above the 25 Lowest Anticipated Service Temperature. 26 27

3.1.2 Hydrogen Content 28 29 Welding electrodes and electrode-flux combinations shall meet the requirements for H16 (16 mL 30 maximum diffusible hydrogen per 100 grams deposited weld metal) as tested in accordance with 31 AWS A4.3-93 Standard Methods for Determination of the Diffusible Hydrogen Content of 32 Martensitic, Bainitic, and Ferritic Steel Weld Metal Produced by Arc Welding. 33 34 Exception: GMAW solid electrodes. 35

DRAFT


3-2

36 3.1.3 Intermixed Filler Metals 37 38 When FCAW-S filler metals are used in combination with filler metals for other processes, 39 including FCAW-G, supplemental notch toughness testing shall be conducted as prescribed in 40 Appendix M. 41 42 3.2 Welding Procedures 43 44 3.2.1 Maximum Interpass Temperature 45 46 The maximum interpass temperature shall not exceed 550oF (290 oC), unless an alternate value is 47 qualified in accordance with 3.2.1.1. The maximum interpass temperature shall be measured at a 48 distance not greater than 3 in. (76 mm) away from the joint. 49 50 3.2.1.1 Maximum Interpass Temperature Qualification 51 52 The temperature limit of 3.2.1 may be increased by qualification testing. The maximum heat 53 input to be used in production shall be used in the qualification testing. The qualification testing 54 shall be performed in accordance with AWS D1.1. The qualified maximum interpass temperature 55 shall be the lowest interpass temperature used for any pass during qualification testing. The weld 56 metal and HAZ shall be tested. The weld metal shall meet all the mechanical properties required 57 by Table 3.1, as applicable. The HAZ CVN toughness shall be tested in accordance with AWS 58 D1.1 Annex III, and shall meet a minimum requirement of 20 ft-lbf at 70oF (27 joules @ 21oC) 59 with specimens taken at both 1 mm and 5 mm from the fusion line. The steel used for the 60 qualification testing shall be of the same type and grade as will be used in production. 61 62 3.2.2 Maximum Air Velocity 63 64 All welds made using the GMAW and FCAW-G processes shall not be performed in winds 65 exceeding 3 mph. Windscreens or other shelters may be used to shield the welding operation 66 from excessive wind. SMAW, FCAW-S and SAW may be performed without limitation to air 67 velocity, provided the welds meet the visual acceptance criteria. 68 69 3.2.3 Bottom Flange Welding Sequence at Access Holes 70 71 When using weld access holes to facilitate CJP groove welds of beam bottom flanges to column 72 flanges or continuity plates, the groove weld shall be sequenced as follows: 73 (1) As far as is practicable, weld starts and stops shall not be directly under the beam web. 74

DRAFT


3-3

(2) Each layer shall be completed across the full width of the flange before beginning the 75 next layer. 76 (3) For each layer, weld starts and stops shall be on the opposite side of the beam web, as 77 compared to the previous layer. 78 79 3.2.4 Demand Critical Welds 80 Welds defined as Demand Critical, as outlined for the individual connections, shall be 81 made using one of the following processes: 82 83 SMAW 84 GMAW except short circuit transfer 85 FCAW 86 SAW 87 88 3.3 Steel Backing at Beam to Column and Continuity Plate to Column Joints 89 90 3.3.1 Steel Backing at Continuity Plates 91 92 Steel backing used at continuity plate to column welds need not be removed. At column 93 flanges, steel backing left in place shall be attached to the column flange using a 94 continuous 5/16 in. (8 mm) fillet weld on the edge below the CJP groove weld. 95 96 When backing is removed, following the removal of backing, the root pass shall be 97 backgouged to sound weld metal and backwelded with a reinforcing fillet. The 98 reinforcing fillet shall have a minimum vertical leg size of 5/16in. (8 mm), and the 99 horizontal leg of the fillet adjacent to the beam flange shall be such that the fillet toe is 100 located on base metal. 101 102 3.3.2 Steel Backing at Beam Bottom Flange 103 104 Where steel backing is used with CJP groove welds between the bottom beam flange and 105 the column, the backing shall be removed. 106 107 Following the removal of backing, the root pass shall be backgouged to sound weld metal 108 and backwelded with a reinforcing fillet. The reinforcing fillet shall have a minimum 109 vertical leg size of 5/16 in. (8 mm), and the horizontal leg of the fillet adjacent to the 110 beam flange shall be such that the fillet toe is located on base metal. 111 112 3.3.3 Steel Backing at Beam Top Flange 113 114 Where steel backing is used with CJP groove welds between the top beam flange and the 115 column, and the backing is not removed, the backing shall be attached to the column by a 116 continuous 5/16 in. (8 mm) fillet weld on the edge below the CJP groove weld. 117 118 3.3.3 Prohibited Welds at Steel Backing 119 120

DRAFT


3-4

Backing at beam flange-to-column flange joints shall not be welded to the underside of 121 the beam flange, nor shall tack welds be permitted at this location. If fillet welds or tack 122 welds are placed between the backing and the beam flange in error, they shall be repaired 123 as follows: 124 (1) The weld shall be removed such that the fillet weld or tack weld no longer attaches 125 the backing to the beam flange 126 (2) The surface of the beam flange shall be ground flush and shall be free of defects 127 (3) Any gouges or notches shall be repaired. 128 129 3.3.4 Nonfusible Backing at Beam Flange-to-Column Joints 130 131 Where nonfusible backing is used with CJP groove welds between the beam flanges and 132 the column, the backing shall be removed, the root backgouged to sound weld metal and 133 backwelded with a reinforcing fillet. The reinforcing fillet shall have a minimum vertical 134 leg size of 5/16 in. (8 mm), and the horizontal leg of the fillet adjacent to the beam flange 135 shall be such that the fillet toe is located on base metal. 136 137 3.4 Details and Treatment of Weld Tabs 138 139 Where used, weld tabs shall be removed to within 1/8 in. (3 mm) of the base metal 140 surface, except at Continuity Plates where removal to within 1/4 in. (6 mm) of the plate 141 edge shall be permitted, and the end of the weld finished. Removal shall be by air carbon 142 arc cutting (CAC-A), grinding, chipping, or thermal cutting. The process shall be 143 controlled to minimize errant gouging. The edges where weld tabs have been removed 144 shall be finished to a surface roughness of 500 µin. (13 µm) or better. Grinding to a flush 145 condition is not required. The contour of the weld end shall provide a smooth transition, 146 free of notches, gouges and sharp corners. At T-joints, a minimum radius in the corner 147 need not be provided. Weld defects not greater than 1/16 in. (1.6 mm) deep shall be 148 faired to a slope not greater than 1:5. Other weld defects shall be excavated and repaired 149 by welding in accordance with an applicable WPS. 150 151 3.5 Tack welds 152 153 Tack welds attaching backing bars and weld tabs shall be placed where they will be 154 incorporated into a final weld. 155 156 3.6 Continuity Plates 157 158 Corners of continuity plates and stiffeners shall be clipped to avoid interference with the 159 radii of the rolled shape to which the members are attached. Along the web, the clip shall 160 be detailed so that the clip extends a distance of at least 1 in. (25 mm) beyond the 161 published “k” detail dimension for the rolled shape. Along the flange, the clip shall be 162 detailed so that the clip does not exceed a distance of ½ in. (12 mm) beyond the 163 published “k1” detail dimension. The clip shall be detailed to facilitate suitable weld 164 terminations for both the flange weld and the web weld. If a curved clip is used, it shall 165 have a minimum radius of ½ in. (12 mm). 166

DRAFT


3-5

167 At the end of the weld adjacent to the column web/flange juncture, weld tabs for 168 continuity plates shall not be used, except when permitted by the Engineer. Unless 169 specified to be removed by the Engineer, weld tabs shall not be removed when used in 170 this location. 171 172 Continuity Plate welds not using or requiring weld tabs in the k-area of a CJP or PJP 173 groove weld shall be transitioned at a slope not to exceed 1:1. The effective length of the 174 weld shall be defined as that portion of the weld having full size. No NDT shall be 175 required on the tapered or transition portion of the weld not having full throat. 176 177 3.7 Quality Control and Quality Assurance 178 179 3.7.1 Quality Assurance Plan Requirements 180 181 Quality Control and Quality Assurance for welding operations shall be done in 182 accordance with the requirements of Appendix Q. 183 184 3.7.2 Visual Welding Inspection 185 186 Visual welding inspections shall be conducted by qualified personnel, in accordance with 187 a written practice, as provided in Appendix Y. 188 189 3.7.3 Nondestructive Testing 190 191 Nondestructive testing of welds and base metals shall be conducted by qualified 192 personnel, in accordance with a written practice, as provided in Appendix N. 193 194

DRAFT


4-1

4. BOLTING REQUIREMENTS 1 2 4.1 Fastener Assemblies 3 4 Twist-off type tension controlled bolt assemblies of equivalent strength may be substituted for 5 ASTM A325 and A490 fastener assemblies. 6 7 4.2 Installation Requirements 8 9 Installation requirements shall be in accordance with AISC Seismic Provisions and the RCSC 10 Specification for Structural Joints using ASTM A325 or A490 Bolts, except as specifically 11 detailed for individual connection types. 12 13 4.3 Quality Control and Quality Assurance 14 15 Quality Control and Quality Assurance for bolting operations shall be done in accordance with 16 the requirements of Appendix Q. 17 18 4.3.1 Visual Bolting Inspection 19 20 Visual bolting inspections shall be conducted by qualified personnel, in accordance with a 21 written practice, as provided in Appendix Y. 22 23

DRAFT


5-1

5. REDUCED BEAM SECTION (RBS) MOMENT CONNECTION 1 2

5.1 General 3 4 5.1.1 Description of the Connection 5

6 In a Reduced Beam Section (RBS) moment connection (Figure 5.1), portions of the beam 7 flanges are selectively trimmed in the region adjacent to the beam-to-column connection. 8

9

c

c

R = Radius of Cut = 4c + b8c

2 2

a b

Reduced BeamSection

Protected Zone

10 11

Figure 5.1 – Reduced Beam Section Connection 12 13 14

In the RBS connection, yielding and hinge formation are intended to occur primarily 15 within the reduced section of the beam, and thereby limit the moment and inelastic 16 deformation demands developed at the face of the column. 17

18 5.2 Systems 19 20 RBS connections are prequalified for use in SMF and IMF systems within the limits of 21 these provisions. 22

5.3 Prequalification Limits 23

5.3.1 Beam Parameters 24

DRAFT


5-2

25 5.3.1.1 Cross-Section Shape and Fabrication Methods 26

27 Beams shall be rolled or welded built-up wide-flange shapes conforming to the 28 requirements of Section 3. 29

5.3.1.2 Depth 30

Beam depth is limited to W36 or shallower for rolled shapes. Depth of built up sections 31 shall not exceed the depth permitted for rolled wide-flange shapes. 32

5.3.1.3 Weight per Foot 33 34 Beam weight is limited to 300 lbs/ft (447 kg/m) or less. 35

5.3.1.4 Flange Thickness 36 37 Beam flange thickness is limited to 1-3/4 in. (45 mm) or less 38

User Note: AISC Seismic Provisions Appendix S provides no limit on flange thickness. 39 The 1-3/4-in. (44.5 mm) limit specified here is based on the 1.68-in. (42.67 mm) flange 40 thickness of a W36x300, with some extrapolation upwards. 41 42 5.3.1.5 Span-to-Depth Ratio 43

5.3.1.5.1 SMF Systems 44

The clear span-to-depth ratio of the beam shall be 7 or greater. 45

5.3.1.5.2 IMF Systems 46

The clear span-to-depth ratio of the beam shall be 5 or greater. 47 48 5.3.1.6 Width-thickness Ratios 49 50 Width–thickness ratios for the flanges and web of the beam shall conform to the limits in 51 Table I-8-1 of the AISC Seismic Provisions. 52 53 When determining the width-thickness ratio of the flange, the value of bf shall not be 54 taken as less than the flange width at the ends of the center two-thirds of the reduced 55 section provided that gravity loads do not shift the location of the plastic hinge a 56 significant distance from the center of the RBS. 57

5.3.1.7 Lateral Bracing 58


DRAFT


5-3

Lateral bracing of beams shall be provided in conformance with Section 9.8 of the AISC 60 Seismic Provisions. Supplemental lateral bracing shall be provided at the reduced section 61 as required in Section 9.8 of the AISC Seismic Provisions for lateral bracing provided 62 adjacent to the plastic hinges. 63

Exception: Where the beam supports a concrete structural slab and is in direct contact 64 with the slab along its span length, supplemental top and bottom flange bracing at the 65 reduced section is not required. 66

Attachment of the supplemental lateral bracing to the beam shall be located between the 67 end of the reduced section farthest from the face of the column and a point within d/2 68 beyond this point away from the reduced section, where d is the depth of the beam. No 69 attachment of lateral bracing shall be made to the beam in the region extending from the 70 face of the column to end of the reduced section farthest from the face of the column. 71


Lateral bracing of beams shall be provided in conformance with Section 10.8 of the AISC 73 Seismic Provisions. 74 75 5.3.1.8 Protected Zone 76 The protected zone consists of the portion of beam between the face of the column and 77 the end of the reduced beam section cut furthest from the face of the column. 78

5.3.2 Column Parameters 79

5.3.2.1 Cross-Section Shape and Fabrication Method 80 81 Columns shall be any of the shapes permitted in Section 2.3.2.2. 82

5.3.2.2 Column Orientation with Respect to Beam 83 84 The beam shall be connected to the flange of the column. 85

5.3.2.3 Depth 86 87 Rolled shape depth shall be limited to W36 or shallower. The depth of built-up wide-88 flange shapes shall not exceed that for rolled shapes. Built up box-shapes shall not have 89 a width or depth exceeding 24 in. (610 mm). Boxed wide-flange shapes shall comply 90 with the provisions for wide-flange shapes. 91

5.3.2.4 Weight per Foot 92 93 No limit. 94

5.3.2.5 Flange Thickness 95 96 No additional requirements for flange thickness. 97

DRAFT


5-4

5.3.2.6 Width – Thickness Ratios 98 99 Width – thickness ratios for the flanges and web of the column shall conform to the limits 100 in Table I-8-1 of the AISC Seismic Provisions. 101

5.3.2.7 Lateral Bracing 102

5.3.2.7.1 SMF Systems 103 Lateral bracing of columns shall conform to Section 9.7 of the AISC Seismic Provisions. 104

5.3.2.7.2 IMF Systems 105 Lateral bracing of columns shall conform to Section 10.7 of the AISC Seismic 106 Provisions. 107

5.4 Beam – Column Relations 108

5.4.1 Panel Zone 109

Panel Zones shall conform to the requirements for SMF or IMF, as applicable, in the 110 AISC Seismic Provisions. 111

5.4.2 Column – Beam Moment Ratio 112

5.4.2.1 SMF Systems 113

The column – beam moment ratio shall conform to the requirements of the AISC Seismic 114 Provisions. In the AISC Seismic Provisions, the value of Σ M*

pb shall be taken equal to Σ 115 (MRBS + Mv), where MRBS is computed according to Eq. 5-5, and where Mv is the 116 additional moment due to shear amplification from the center of the RBS to the centerline 117 of the column. Mv can be computed as VRBS (a + b/2 + dc/2), where VRBS is the shear at the 118 center of the RBS computed per Step 4 of Section 5.8, a and b are the dimensions shown 119 in Fig. 5.1, and dc is the depth of the column. 120

5.4.2.2 IMF Systems 121

The column – beam moment ratio shall conform to the requirements for IMF in the AISC 122 Seismic Provisions. 123

5.5 Welds 124

Beam flanges shall be connected to column flanges using complete joint penetration 125 groove welds. Beam flange welds shall conform to the requirements for Demand Critical 126 Welds in Section 3. 127

5.5.2 Weld Access Holes 128 129 Weld access hole geometry shall conform to the requirements of the AISC Specification 130 Section J1.6. 131

DRAFT


5-5

5.6 Beam Web-to-Column Connection 132

5.6.1 Required Shear Strength 133 The required shear strength of the beam web connection shall be determined according to 134 Equation 5-10. 135

5.6.2 Beam Web Connection Details 136


The beam web shall be connected to the column flange using a complete joint penetration 138 groove weld extending between weld access holes. The shear tab shall be designed for 139 erection loads and serve as backing for the complete joint penetration weld. The thickness 140 of the shear tab shall be at least 3/8 in. (10 mm). The shear tab shall be welded to the 141 column flange using a weld sized for erection loads. Weld tabs are not required at the 142 ends of the complete joint penetration web weld. Welding of the shear tab to the beam 143 web is not required. Erection bolts shall be provided as required. 144

5.6.2.2 IMF Systems 145 146 The beam web shall be connected to the column flange per Section 5.6.2.1. 147 148 Exception: It is permitted to connect the beam web to the column flange using a bolted 149 shear tab. The bolted shear tab shall be designed as a slip critical connection, with the 150 design slip resistance per bolt determined according to Section J3.9a of the AISC 151 Specification. The nominal bearing strength at bolt holes shall not be taken greater than 152 the value given by Equation J3-6a of the AISC Specification. The design shear strength 153 of the shear tab shall be determined based on shear yielding of the gross-section and on 154 shear fracture of the net section. The shear tab shall be welded to the column flange with 155 a complete joint penetration groove weld, or with fillet welds on both sides of the shear 156 tab. Minimum size of the fillet weld on each side of the shear tab shall be 75-percent of 157 the thickness of the shear tab. Standard size holes shall be provided in the beam web and 158 in the shear tab, except that short-slotted holes (with the slot parallel to the beam flanges) 159 may be used in either the beam web or in the shear tab, but not in both. Bolts are 160 permitted to be pretensioned either before or after welding. 161

The design shear strength of the shear tab shall be determined based on shear yielding of 162 the gross-section and on shear fracture of the net section. 163 164 The shear tab shall be welded to the column flange with a complete joint penetration 165 groove weld, or with fillet welds on both sides of the shear tab. Minimum size of the fillet 166 weld on each side of the shear tab shall be 75-percent of the thickness of the shear tab. 167

Standard size holes shall be provided in the beam web and in the shear tab, except that 168 short-slotted holes (with the slot parallel to the beam flanges) shall be permitted in either 169 the beam web or in the shear tab, but not in both. Bolts are permitted to be pretensioned 170 either before or after welding. 171

DRAFT


5-6

172 5.7 Fabrication of Flange Cuts 173 174 The reduced beam section shall be made using thermal cutting to produce a smooth 175 curve. The surface profile of thermal cut surfaces shall be 500 µin. (0.0127 mm) in 176 accordance with ANSI B46.1, as measured using AWS C4.7 Sample 4 or similar visual 177 comparator. All transitions between the reduced beam section and the unmodified beam 178 flange shall be rounded in the direction of the flange length to minimize notch effects due 179 to abrupt transitions. Corners between the reduced section surface and the top and bottom 180 of the flanges shall be ground to remove sharp edges, but a minimum chamfer or radius is 181 not required. 182 183 Depth of thermal cutting tolerances shall be plus or minus 1/4 in. (6 mm) from the 184 theoretical cut line, but not more than plus or minus 3/8 in. (10 mm) between cuts. 185 186 Gouges and notches that occur in the thermal cut RBS surface may be repaired by 187 grinding if not more than ¼ in. (6mm) deep. The gouged or notched area shall be faired 188 by grinding so that a smooth transition exists, and the total length of the area ground for 189 the transition shall be no less than 10 times the depth of the removed gouge. If a sharp 190 notch exists, the area shall be inspected by MT after grinding to ensure that the entire 191 depth of notch has been removed. Grinding that increases the depth of the RBS cut more 192 than 1/4 in. beyond the specified depth of cut is not permitted. 193 194 Gouges and notches that exceed 1/4 in. (6mm) in depth, but not to exceed 1/2 in. (12mm) 195 in depth, and those notches and gouges where repair by grinding would increase the 196 effective depth of the RBS cut beyond tolerance, may be repaired by welding. The notch 197 or gouge shall be removed and ground to provide a smooth radius of not less than ¼-in. 198 in preparation for welding. The repair area shall be preheated to a temperature of 150oF 199 or the value specified in AWS D1.1 Table 3.2, whichever is greater, measured at the 200 location of the weld repair. Repair welding shall be done with E7018 SMAW electrodes 201 or other filler metals meeting the requirements of Section 3.1 for Demand Critical joints. 202 A special WPS is required for this repair. Following welding, the repair weld shall be 203 ground to a smooth contour meeting the RBS requirements, with a surface roughness not 204 to exceed 500 µin. (0.0127 mm). The welded repair area shall be inspected using 205 magnetic particle testing (MT). 206 207 Notches and gouges exceeding 1/2 in. (12mm) in depth may be repaired only with the 208 approval of the Engineer. 209

5.8 Design Procedure 210

STEP 1 - Choose trial values for the beam sections, column sections and RBS dimensions 211 a, b and c (Figure 5.1) as follows: 212

0.5bf ≤ a ≤ 0.75bf (5-1) 213

0.65d ≤ b ≤ 0.85d (5-2) 214

DRAFT


5-7

0.1bf ≤ c ≤ 0.25bf (5-3) 215

216

where: 217

bf = beam flange width, in. (mm) 218 219 db = beam depth, in. (mm) 220

a = distance from face of column to start of RBS cut, in. (mm) 221

b = length of RBS cut, in. (mm) 222 223 c = depth of cut at minimum section of RBS, in. (mm) 224 225

Confirm that the beams and columns are adequate for all load combinations specified by 226 the building code, including the reduced section of the beam and that the design 227 interstory drift for the frame complies with applicable limits specified by the building 228 code. Calculation of elastic drift shall consider the effect of the reduced beam section. In 229 lieu of specific calculations, effective elastic drifts may be calculated by multiplying 230 elastic drifts based on gross beam sections by 1.10 for flange reductions up to 50 percent 231 of the beam flange width. Linear interpolation may be used for lesser values of beam 232 width reduction. 233

STEP 2 - Compute the plastic section modulus at the minimum section of the RBS, as 234 follows: 235

236 Ze = Zb – 2 c tf (d – tf ) (5-4) 237

238

where: Ze = plastic section modulus at minimum section of 239 RBS, in.3 (mm3) 240

Zb = plastic section modulus for full beam cross-section, 241 in.3 (mm3) 242

tf = beam flange thickness, in. 243 244

STEP 3 - Compute the maximum moment expected at the center of the RBS, as follows: 245

Mpr = Cpr Ry Ze Fy (5-5) 246

247

where: Mpr = Probable maximum moment at center of RBS, kip-in. (N-248 mm) 249

250 251

DRAFT


5-8

STEP 4 - Compute the shear force at the center of the RBS cuts at each end of the beam. 252 253 The shear force at the center of the RBS cuts shall be determined by methods of statics 254 applied to a free body diagram of the portion of the beam between the center of RBS cuts. 255 This calculation shall assume the moment at the center of each RBS cut is Mpr and shall 256 include gravity loads acting on the beam based on the load combination 1.2D + 0.5L + 257 0.2S. 258

259 An example calculation is shown in Figure 5.2 for the case of a beam with a uniformly 260 distributed gravity load. 261

262

ba

LC RBS

L' = distance between centers of RBS cuts

b

LC RBS

a

L = distance between column centerlines

w = uniform beam gravity load

shsh

263

(a) Beam with RBS Cuts and Uniform Gravity Load 264

LC RBS

L' = distance between centers of RBS cuts

LC RBSw = uniform beam gravity load

MprVRBS'Mpr VRBS

265

2

2pr

RBS

M wLVL

′= +

′ (5-6a) 266

2

2pr

RBS

M wLVL

′′ = −

′ (5-6b) 267

(b) Free Body Diagram of Beam Between RBS Cuts and Calculation of Shear at RBS 268 269

Figure 5.2 – Example Calculation of Shear at Center of RBS Cuts 270

DRAFT


5-9

271 For gravity load conditions other than a uniform load, the appropriate adjustment 272 should be made to the free body diagram in Fig. 5.2(b) and to Eqs. 5-6a and 5-6b. 273

274 Equations 5-6a and 5-6b assume that plastic hinges will form at the RBS at each 275 end of the beam. If the gravity load on the beam is very large, the plastic hinge at 276 one end of the beam may move towards the interior portion of the beam span. If 277 this is the case, the free body diagram in Fig. 5.2 should be modified to extend 278 between the actual plastic hinge locations. To check if Eqs. 5-6a and 5-6b are 279 valid; draw the moment diagram for the segment of the beam shown in Fig. 280 5.2(b), i.e., for the segment of the beam between the centers of the RBS cuts. If 281 the maximum moment occurs at the ends of the span, then Eqs. 5-6a and 5-6b are 282 valid. If the maximum moment occurs within the span, and exceeds Mpe of the 283 beam (see Eq. 5-8), then the modification described above will be needed. 284 285

STEP 5 - Compute the maximum moment expected at the face of the column. 286 287 The moment at the face of the column shall be computed from a free body 288 diagram of the segment of the beam between the center of the RBS and the face of 289 the column, as illustrated in Fig. 5.3. 290

291

b2a +

LC RBS

MMM prff VRBS

s =h 292 Figure 5.3 - Free Body Diagram Between Center of RBS and Face of Column 293

294 Based on this free body diagram, the moment at the face of the column is 295 computed as follows: 296

297 Mf = Mpr + VRBS Sh (5-7) 298 299

where: Mf = maximum moment expected at face of column, kip-300 in (N-mm) 301

VRBS = larger of the two values of shear force at the centers 302 of the RBS cuts at each end of the beam, kips (N) 303

Sh = a + b/2, in (mm) 304 305

DRAFT


5-10

Equation 5-7 neglects the gravity load on the portion of the beam between the 306 center of the RBS and the face of the column. If desired, the gravity load on this 307 small portion of the beam can be included in the free body diagram shown in Fig. 308 5.3 and in Eq. 5-7. 309 310

STEP 6 - Compute the plastic moment of the beam based on the expected yield stress. 311 312 Mpe = ZbRyFy (5-8) 313 314

where: Mpe = plastic moment of beam based on expected yield 315 strength, kip-in (N-mm) 316

STEP 7 - Check that Mf does not exceed Mpe, as follows 317 318

Mf ≤ Mpe (5-9) 319 320

If Eq. 5-9 is not satisfied, increase the value of c, and/or decrease the values of a 321 and b, and repeat Steps 2 through 7. 322

323

STEP 8 – Determine the required shear strength Vu of beam and beam web-to-column 324 connection. 325 326 Vu shall be determined resulting from gravity loads acting on the beam based on the load 327 combination 1.2D + 0.5L + 0.2S and based on the shear produced assuming a moment of 328 Mpr is acting at the center of each RBS cut, as follows: 329

330

2 pr

u gravity

MV V

L= +

′ (5-10) 331

332

where: Vu = required shear strength of beam and beam web-to-333 column connection, kips (N) 334

L′ = distance between centers of RBS cuts, in. (mm) 335 Vgravity = beam shear force resulting from 1.2D + 0.5L + 336

0.2S, kips (N) 337 338

Check design shear strength of beam according to Chapter G of the AISC 339 Specification. 340

341 STEP 9 – Design the beam web-to-column connection according to Section 5.6. 342 343 STEP 10 – Check Continuity Plate requirements per Chapter 2. 344

DRAFT


5-11

345 STEP 11 – Check column Panel Zone per Section 5.4.1. 346

347 STEP 12 – Check column-beam moment ratio per Section 5.4.2. 348

349

DRAFT


6-1

6. BOLTED UNSTIFFENED AND STIFFENED EXTENDED END-PLATE 1 MOMENT CONNECTIONS 2

3 6.1 Description of Connection 4

Bolted end plate connections are made by welding the beam to an end plate with 5 CJP welds for the beam to plate connection and fillet or groove welding the beam 6 web to the plate. The three end-plate configurations shown in Figure 6.1 are 7 covered in this section and are prequalified under the AISC Seismic Provisions 8 within the limitations of this Standard. 9

10

11

12

13

14

15

16

17

18

19

20

(a) Four Bolt Unstiffened, 4E (b) Four Bolt Stiffened, 4ES (c) Eight Bolt Stiffened, 8ES 21

FIGURE 6.1: EXTENDED END PLATE CONFIGURATIONS 22 23

The behavior of this type of connection can be controlled by a number of different modes 24 including flexural yielding of the beam section, flexural yielding of end plates, yielding 25 of the column panel zone, tension failure of the end plate bolts, shear failure of the end 26 plate bolts or cracking of various welded connections. The intent of the design criteria 27 provided here is to provide sufficient strength in the elements of the connections to 28 ensure that the inelastic deformation of the connection is achieved by beam yielding. 29

30 6.2 Research Reviewed and Basis for Prequalification 31 32 Section 6.11 contains a list of publications on end-plate connections that were reviewed 33 and that provide the primary basis for Prequalification. These publications report the 34 results of experimental and analytical studies on the performance of these connections 35 and the development of design procedures. 36 37

DRAFT


6-2

6.3 Systems 38 39 End plate connections are prequalified for use in IMF systems. 40 41 End plate connections are also prequalified for use in SMF systems not supporting 42 structural concrete slabs. 43

6.4 Prequalification Limits 44

6.4.1 Acceptable Connection Parameters 45 46 Table 6.1 is a summary of the range parameters that have been satisfactorily tested. All 47 connection elements shall be within the ranges shown. 48

49

TABLE 6.1: PARAMETRIC LIMITATIONS ON PREQUALIFICATION 50

Four Bolt Unstiffened

(4E) Four Bolt Stiffened

(4ES) Eight Bolt Stiffened

(8ES)

Parameter Maximum,

in.(mm) Minimum in.(mm)

Maximum in.(mm)

Minimum In.(mm)

Maximum in.(mm)

Minimum in.(mm)

tp 2.25 (57) 0.50 (12) 1.375 (35) 0.50 (13) 2.5 (64) 0.75 (19)

bp 10.63 (270) 7.00 (178) 10.63 (270) 10.63 (270) 15.0 (381) 9.00 (229)

g 6.0 (152) 4.00 (102) 6.00 (152) 3.25 (83) 6.00 (152) 5.00 (127)

pf 4.5 (114) 1.5 (38) 5.38 (137) 1.63 (41) 2.00 (51) 1.63 (41)

pb - - - - 3.75 (95) 3.50 (89)

d 55.0 (1400) 25.0 (635) 24.0 (610) 13.7 (349) 36.0 (914) 18.38 (467)

tf 0.75 (19) 0.375 (10) 0.75 (19) 0.375 (10) 1.00 (25) 0.625 (16)

bf 9.25 (235) 6.0 (152) 9.00 (229) 6.00 (152) 12.3 (312) 7.62 (193)

Where: 51 tp = thickness of the end plate, in.(mm) 52 bp= width of the end-plate, in.(mm) 53 g = horizontal distance between bolts, in.(mm) 54 pf = vertical distance between beam flange and the nearest row of bolts, 55

in.(mm) 56 pb = distance between the inner and outer row of bolts in an eight bolt 57

DRAFT


6-3

connection, in.(mm) 58 d = depth of the connecting beam, in.(mm) 59 tf = beam flange thickness, in.(mm) 60 bf = beam flange width, in.(mm) 61 62

6.4.2 Beam Parameters 63

6.4.2.1 Cross-Section Shape and Fabrication Methods 64

Beams shall be rolled or welded built-up wide-flange shapes. 65 66 For welded built-up sections, the beam web and flanges shall be connected using a pair of 67 fillet welds each at least ¼ in. (6mm) or 0.75 times the beam web thickness, whichever is 68 greater. The length shall be at least the depth of beam or 3 times the width of flange, 69 whichever is less. The weld size shall not be less than that required to accomplish shear 70 transfer from the web to the flanges. 71

6.4.2.2 Depth 72

Beam depth is limited to values shown in Table 6.1 shapes. 73

6.4.2.3 Weight per Foot 74 75 There is no beam weight limit. 76

6.4.2.4 Flange Thickness 77 78 Beam flange thickness is limited to the values shown in Table 6.1. 79 80

6.4.2.5 Span-to-Depth Ratio 81


The clear span-to-depth ratio of the beam shall be 7 or greater. 83


The clear span-to-depth ratio of the beam shall be 5 or greater. 85 86 6.4.2.6 Width-thickness Ratios 87 88 Width–thickness ratios for the flanges and web of the beam shall conform to the limits in 89 Table I-8-1 of the AISC Seismic Provisions. 90 91 6.4.3 Lateral Bracing 92

DRAFT


6-4


Lateral bracing of beams shall be provided in conformance with Section 9.8 of the AISC 94 Seismic Provisions. 95


Lateral bracing of beams shall be provided in conformance with Section 10.8 of the AISC 97 Seismic Provisions. 98 99 6.4.4 Protected Zone 100

101 The protected zone consists of the portion of beam between the face of the column and a 102 location one beam depth from the face of the column. 103 104 6.4.4.1 Unstiffened End-Plate Connections 105 106 The protected zone consists of the portion of beam between the face of the column and a 107 distance equal to the depth of the beam or 3 times the width of flange from the face of the 108 column, whichever is less. 109 110 6.4.4.2 Stiffened End Plate Connections 111 112 The protected zone consists of the portion of beam between the face of the column and a 113 distance equal to the location of the end of the stiffener plus one half the depth of the 114 beam or 3 times the width of the beam flange, whichever is less. 115 116 6.5 Column Parameters 117

6.5.1 Column Orientation with Respect to Beam 118 119 The beam shall be connected to the flange of the column. 120

6.5.2 Depth 121 122 The column depth shall be limited to the beam depth or shallower. 123

6.5.3 Weight per Foot 124 125 No limit. 126

6.5.4 Flange Thickness 127 128 No additional requirements for flange thickness. 129

6.5.5 Width – Thickness Ratios 130 131

DRAFT


6-5

Width – thickness ratios for the flanges and web of the column shall conform to the limits 132 in Table I-8-1 of the AISC Seismic Specification. 133

6.6 Beam – Column Relations 134

6.6.1 Panel Zone 135

Panel zones shall conform to the applicable requirements of the AISC Seismic 136 Provisions. 137

6.6.2 Column – Beam Moment Ratio 138


The column – beam moment ratio shall conform to the requirements for SMF in the 140 AISC Seismic Provisions. 141


The column – beam moment ratio shall conform to the requirements for IMF in the AISC 143 Seismic Provisions. 144

6.7 Continuity Plates 145

6.7.1 Determining Need for Continuity Plates 146

Continuity plates shall be provided if the web or the unstiffened column flange is not 147 sufficient. See Section 6.10. 148

6.7.2 Continuity Plate Thickness 149

When required, Continuity plates shall also conform to the requirements of Section J11.8 150 of the AISC Specification. 151

6.7.3 Continuity Plate to Column Attachment 152 153

Continuity Plates shall be welded in accordance with Section 2.4.4.2, except as follows: 154

Continuity plates less than or equal to 3/8 in.(10 mm) shall be permitted to be welded to 155 column flanges using double sided fillet welds. Fillet welds shall be sufficient to develop 156 the strength of the continuity plate. 157 158 6.8 Bolt Grade 159 160 Bolts shall be ASTM A325 or A490. 161 162 6.9 Connection Detailing. 163 164

DRAFT


6-6

6.9.1 Gage 165 166

The maximum gage dimension is limited to the width of the connected beam flange. 167 168

6.9.2 Pitch and Row Spacing 169 170

The minimum pitch dimension, distance from the face of the beam flange to the 171 centerline of the nearer bolt row, for heavy hex bolts is the bolt diameter plus 1/2 in. (12 172 mm) for bolts up to 1 in. (25 mm) diameter, and the bolt diameter plus 3/4 in. (19 mm) 173 for larger diameter bolts. 174

175 The spacing of the bolt rows shall be at least 2-2/3 times the bolt diameter. 176 177 User Note: A distance of 3 times the bolt diameter is preferred. The distance shall be 178 sufficient to provide clearance for any welds in the region. 179

180 6.9.3 End-Plate Width 181

182 The width of the end plate shall be greater than or equal to the connected beam flange 183 width. The effective end plate width shall not be taken as greater than the connected 184 beam flange plus 1 in. (25mm) 185

186 6.9.4 End-Plate Stiffener 187

188 The two extended stiffened end plate connections, Figures 6.1(b) and (c), utilize a gusset 189 plate welded between the connected beam flange and the end plate to stiffen the extended 190 portion of the end plate. The minimum stiffener length shall be: 191

192

30tan

hL st

st = 193

where hst is the height of the end plate from the outside face of the beam flange to the end 194 of the end plate, as shown in Figure 6.2. 195 196 To facilitate welding of the stiffener, the stiffener plates shall be terminated at the beam 197 flange and at the end of the end plate with landings approximately 1 in. (25mm) long. 198 The stiffener shall be clipped where it meets the beam flange and end plate to provide 199 clearance between the stiffener and the beam flange weld. 200 201 User Note: Figure 6.3 illustrates the recommended layout of the end plate stiffener 202 geometry. 203 204 When the beam and end plate stiffeners have the same material strengths, the thickness of 205 the stiffeners shall be greater than or equal to the beam web thickness. If the beam and 206 end plate stiffener have different material strengths, the thickness of the stiffener shall be 207

DRAFT


6-7

greater than the ratio of the beam-to-stiffener plate material yield stress times the beam 208 web thickness. 209 210 6.9.5 Finger Shims 211

212 Use of finger shims at the top and/or bottom of the connection and on either or both sides, 213 subject to the limitations of RCSC Specification Section 5.1, as illustrated in Figure 6.3, 214 is permitted. 215

216 217 218

219

220 221

FIGURE 6.2: END PLATE STIFFENER LAYOUT AND GEOMETRY (8ES) 222 223 224

Lst

hst

1"30°

DRAFT


6-8

225 226 227 FIGURE 6.3: TYPICAL USE OF FINGER SHIMS 228

229 230

6.9.3 Composite Slab Detailing for IMF 231 232 In addition to the Protected Zone limitations, shear studs shall not be placed along the top 233 flange of the connecting beams for a distance from the face of the column, one and a half 234 times the depth of the connecting beam. 235 236 Compressible expansion joint material, at least ½ in. (12 mm) thick, shall be installed 237 between the slab and the column face. 238 239 6.9.4 Welding Details 240 241 Welding of the beam to the end plate shall conform to the following sections. 242 243 6.9.4.1 Weld Access Holes 244 245 Weld access holes shall not be used. 246 247 6.9.4.2 Beam Web to End-Plate Welds 248 249

DRAFT


6-9

The beam web to end-plate connection shall be made using either fillet welds or CJP 250 groove welds. When used, the fillet welds shall be sized to develop the full strength of the 251 beam web in tension within 6 in. (150mm) of the inside bolt row. 252 253 6.9.4.3 Beam Flange to End-Plate Welds 254 255 The beam flange to end plate connection shall be made using a CJP groove weld without 256 backing. The CJP groove weld shall be made such that the root of the weld is on the 257 beam web side of the flange. The inside face of the flange shall have a 5/16 in. (8mm) 258 fillet weld. These welds shall be demand critical. 259 260 Backgouging of the root is not required in the flange directly above and below the beam 261 web for a length equal to 1.5k1. A PJP groove weld shall be permitted at this location. 262 263 6.9.4.4 End Plate Stiffener Welds 264 265 The connection of the end plate stiffener to the outside face of the beam flange and to the 266 face of the end plate shall be made using CJP groove welds, except when the stiffener is 267 3/8 in. (10mm) thick or less, it shall be permitted to use fillet welds that develop the 268 strength of the stiffener. 269 270

DRAFT


6-

10

270 6.10 Design Procedure 271 272

Connection geometry is shown in Figures 6.5, 6.6, and 6.7 for the 4E, 4ES, and 8ES 273 connections, respectively. 274

275

276

277

278

279

tfc

c t sc

p s

i p s

o

tp d

t fb

p fi

d e

p fo

b fc

g

t wc

dct w

b

b fb

b p

280 281 FIGURE 6.4: FOUR BOLT UNSTIFFENED EXTENDED, 4E, END PLATE GEOMETRY 282

283

DRAFT


6-

11

Lst h st c

tfcp s

o p s

i t sc

t w

c

b fc t s

dc

g tp d

d e

p fi

p fo t fb

b fb

t wb

b p

284 285

FIGURE 6.5: FOUR BOLT STIFFENED EXTENDED, 4ES, END PLATE GEOMETRY286

DRAFT


6-

12

b fc

d e

p b

p b

c

tfc tp

Lst

h st

p si

t sc p so

d

t fb

p fo

p fi

t wc

g

dc

t wb t s b fb

b p

287 288

FIGURE 6.6: EIGHT BOLT STIFFENED EXTENDED, 8ES, END PLATE GEOMETRY 289 290 End Plate and Bolt Design 291 292 1) Determine the sizes of the connected members (beams and column) and compute the moment 293

at the face of the column, Muc. 294 295

pupeuc LVMM += (6.1) 296 297

where pe pr y y xM C R F Z= (6.2) 298 299 Vu = shear at the plastic hinge 300 301 sh = distance from the face of the column to the plastic hinge 302 303

fb 32/d

min = for unstiffened connection (4E) (6.3) 304

305 pst tL += for stiffened connections (4ES, 8ES) (6.4) 306 307 Ry = the ratio of the expected yield strength to the specified minimum yield strength, 308 from AISC SeismicProvisions. 309

DRAFT


6-

13

310 d = depth of the connecting beam, in. (mm) 311 312 bf = width of the beam flange, in. (mm) 313 314 Lst = length of the end plate stiffener, in. (mm) 315 316 tp = thickness of the end plate, in. (mm) 317 318

2) Select one of the three end plate moment connection configurations and establish preliminary 319 values for the connection geometry (g, pfi, pfo, pb, etc.) and bolt grade. 320

321 3) Determine the required bolt diameter, db Req’d, using one of the following expressions. 322

323

( ) Req'd0 1

2

ucb

n t

MdF h hπ φ

=+

for four bolt connections (4E, 4ES) (6.5) 324

φn = 0.9 325 326

327

( ) Req'd1 2 3 4

2

ucb

n t

MdF h h h hπ φ

=+ + +

for eight bolt connections (8ES) (6.6) 328

φn = 0.9 329 330 where Ft = specified bolt tensile strength, 90 ksi (621 MPa) for A325 bolts and 113 ksi (779 331

MPa) for A490 bolts, 332 333 hi = distance from the centerline of the beam compression flange to the centerline of 334 the ith tension bolt row, in. (mm). 335

336 4) Select a trial bolt diameter, db, greater than that required in Step 3 and calculate the no prying 337

bolt moment strength, Mnp. 338 339

( )10tnp hh P2M += for four bolt connections (4E, 4ES) (6.7) 340 341

( )4321tnp hhhh P2M +++= for eight bolt connections (8ES) (6.8) 342

where

π===

4d

FA F strength leBolt tensi P2b

tbtt (6.9) 343

Ab = the nominal cross sectional area of the selected bolt diameter, in2 (mm2) 344 345 db = selected nominal bolt diameter, in. (mm) 346

347 5) Determine the required end plate thickness, tp Req’d. 348

349

DRAFT


6-

14

Req'd

1.11

npp

d yp p

Mt

F Yφ= (6.10) 350

φd = 1.0 351 352 where Fyp = the end plate material yield strength, ksi (N/mm2) 353

354 Yp = the end plate yield line mechanism parameter from Table 6.2, 6.3, or 6.4. 355

356 6) Select an end plate thickness not less than the required value. 357 358 7) Calculate the factored beam flange force 359 360

tdM

Ffb

ucfu

−= (6.11) 361

362 d = depth of the beam, in. (mm) 363 364

8) Check shear yielding resistance of the extended portion of the four bolt extended unstiffened 365 end plate (4E): 366

367 Ffu / 2 < φdRn = 0.6 Fyp bp tp (6.12) 368

369 where bp = width of the end plate 370

371 If Inequality 6.12 is not satisfied, increase the end plate thickness until it is satisfied. 372

373 9) Check shear rupture resistance of the extended portion of the end plate in the four bolt 374

extended unstiffened (4E): 375 376

Ffu / 2 < φnRn = φn0.6 Fup An (6.13) 377 378

φn = 0.9 379 380

where Fup = minimum tensile strength of the end plate, ksi (N/mm2) 381 382 An = net area of the end plate = [bp – 2 (db + 1/8)] tp when (6.14) 383 standard holes are used, in.2 (mm2) 384 385 db = diameter of the bolts 386 387

If Inequality 6.13 is not satisfied, increase the end plate thickness until it is satisfied. 388 389

DRAFT


6-

15

10) If using either the four bolt extended stiffened (4ES) or eight bolt extended stiffened (8ES) 390 connection, select the end plate stiffener thickness and design the stiffener-to-beam flange 391 and stiffener-to-end plate welds. 392

393

=

ys

ybwbd'req,s F

Ftt (6.15) 394

395 where twb = thickness of the beam web, in. (mm) 396

397 Fyb = specified minimum yield stress of beam material, ksi (N/mm2) 398 399 Fys = specified minimum yield stress of stiffener material, ksi (N/mm2) 400

401 The stiffener geometry shall conform to the requirements of Section 6.9.4. In addition, to 402 prevent local buckling of the stiffener plate the following width-to-thickness criterion shall 403 be satisfied. 404

405

ysFE 56.0

ststh

< or 1.79 ysst

Ft hs E

≥ (6.16) 406

407 where hst = the height of the stiffener 408 409 The stiffener-to-beam flange and stiffener-to-end plate welds should be designed to develop 410 the stiffener plate in shear at the beam flange and in tension at the end plate. Either fillet or 411 CJP groove welds are suitable for the weld of the stiffener plate to the beam flange. If the 412 stiffener plate thickness is greater than 3/8 in., CJP groove welds shall be used for the 413 stiffener-to-end plate weld. Otherwise, double-sided fillet welds may be used. 414

415 11) The bolt shear rupture strength of the connection is conservatively assumed to be provided by 416

the bolts at one (compression) flange, thus 417 418

Vu < φn Rn = φn (nb) Fv Ab (6.17) 419 φn = 0.9 420 421 where nb = number of bolts at the compression flange, four for 4ES, and eight for 8ES 422

connections 423 424 Fv = nominal shear strength of bolts from Table J3.2 of the AISC Specification, ksi 425

(N/mm2) 426 427 Ab = nominal gross area of bolt, in2 (mm2) 428

429 12) Check bolt bearing / tear out failure of the end plate and column flange: 430 431

DRAFT


6-

16

Vu < φn Rn = φn(ni) Rn (Inner Bolts) + φn(no) Rn (Outer Bolts) (6.18) 432 433

φd = 1.0 434 435

where ni = number of inner bolts (two for 4E and 4ES, and four for 8ES connections) 436 437 no = number of outer bolts (two for 4E and 4ES, and four for 8ES connections) 438 439 φd Rn = 1.2 Lc tFu < 2.4 db t Fu for each bolt (6.19) 440 441 Lc = clear distance, in the direction of force, between the edge of the hole and the 442

edge of the adjacent hole or edge of the material, in. (mm) 443 444 t = end plate or column flange thickness, in. (mm) 445 446 Fu = specified minimum tensile strength of end plate or column flange material, ksi 447 (N/mm2) 448 449 db = diameter of the bolt, in2 (mm2) 450 451 φd = 1.0 452

453 13) Design the flange to end plate and web to end plate welds. 454 455 Column Side Design 456 457 14) Check the column flange for flexural yielding 458

459

Req'dd

1.11

np

cf cfyc c

Mt t

F Yφ= < (6.20) 460

461 where Fyc = specified yield stress of column flange material, ksi (N/mm2) 462

463 Yc = unstiffened column flange yield line mechanism parameter from Table 6.5 or 464

Table 6.6 465 466 tcf = column flange thickness, in. (mm) 467

468 If Inequality 6.20 is not satisfied, increase the column size or add web stiffeners (continuity 469 plates). 470

471 If stiffeners are added, Inequality 6.20 must be checked using Yc for the stiffened column 472

flange from Tables 6.5 and 6.6. 473 474

DRAFT


6-

17

15) If stiffeners are required for column flange flexural yielding, determine the required stiffener 475 force. 476

477 The column flange flexural design strength is 478 479

2cf yc c fctM F Y= (6.21) 480

481 Therefore, the equivalent column design force is 482

483

( )cf

d nfb

MR

d tφ =

− (6.22) 484

485 Using Rn, the required force for stiffener design is determined in Step 19. 486 487

16) Check the local column web yielding strength of the unstiffened column web at the beam 488 flanges. 489

490 Strength requirement: φdRn > Ffu (6.23) 491

492 ( )6 2

dyct c p wcn

NC k t tFRφ = + + (6.24) 493

494 where Ct = 0.5 if the distance from the column top to the top face of the beam flange is less 495

than the depth of the column 496 497 = 1.0 otherwise 498 499 kc = distance from outer face of the column flange to web toe of fillet (design value), 500

in. (mm) 501 502 N = thickness of beam flange, in. (mm) 503 504 tp = end plate thickness, in. (mm) 505 506 Fyc = specified yield stress of the column web material, ksi (N/mm2) 507 508 twc = column web thickness, in. (mm) 509 510 d = depth of the beam, in. (mm) 511 512 tfb = thickness of beam flange, in. (mm) 513

514 φd = 1.0 515 516

DRAFT


6-

18

If the strength requirement (φdRn > Ffu) is not satisfied, then column web continuity plates are 517 required. 518

519 17) Check the unstiffened column web buckling strength at the beam compression flange. 520

521 Strength requirement: φnRn > Ffu (6.25) 522

523 When Ffu is applied a distance greater than or equal to dc/2 from the end of the column 524 525

3 24 wc ycn n

t E FR

hφ = (6.26) 526

527 When Ffu is applied a distance less than dc/2 from the end of the column 528

529 3 12 wc yc

n n

t E FR

hφ = (6.27) 530

531 where h = clear distance between flanges less the fillet or corner radius for rolled shapes; 532

clear distance between flanges when welds are used for built-up shapes, in. (mm) 533 534

If the strength requirement (Rn > Ffu) is not satisfied, then column web continuity plates are 535 required. 536

537 538 539 18) Check the unstiffened column web crippling strength at the beam compression flange. 540

541 Strength requirement: Rn > Ffu (6.28) 542 543 When Ffu is applied a distance greater than or equal to dc/2 from the end of the column 544

545 1.5

2wc

0.80 t 1 3 yc fcwc

n nc fc wc

E F ttNRd t t

φ = +

(6.29) 546

547 When Ffu is applied a distance less than dc/2 from the end of the column 548

549 For N/dc < 0.2, 550

551

wc

fcyc

fc

wc

cn t

tFEtt

dNR

31 t0.40

5.1

2wc

+=φ (6.30) 552

553 For N/dc > 0.2, 554

DRAFT


6-

19

555

wc

fcyc

fc

wc

cn t

tFEtt

dNR

2.04 1 t0.40

5.1

2wc

−+=φ (6.31) 556

557 where N = thickness of beam flange plus 2 times the groove weld reinforcement leg size, in. 558

(mm) 559 560 dc = overall depth of the column, in. (mm) 561

562 If the strength requirement (Rn > Ffu) is not satisfied, then column web continuity plates are 563 required. 564

565 19) If stiffener plates are required for any of the column side limit states, the required strength is 566

567 Fsu = Ffu - min φRn (6.32) 568

569 where min φRn = the minimum design strength value from Steps 15 (column flange 570 bending), 16 (column web yielding), 17 (column web buckling), and 17 (column web 571 crippling). 572

573 The design of the continuity plates shall also conform to section K1.9 of the AISC 574 Specification. 575

576

DRAFT


6-

22

TABLE 6.1: SUMMARY OF FOUR BOLT EXTENDED UNSTIFFENED END PLATE DESIGN STRENGTH 549 550

End Plate Geometry and Yield Line Pattern Bolt Force Model

End Plate

p2pypbpl Y t FM φφ =

( )[ ]sphg2

21

p1h

s1

p1h

2b

Y if1of

0if

1p

p ++

−

+

+=

gb21s p = φb = 0.90 Note: If pfi > s, use pfi = s

Bolt Rupture ( )1otnp hhP2M += φφ φ = 0.75

551 552 553

554 555

h1h0

gbp

tw

tp

stfpfi

pfode 2 Pt

2 Pt

Mnp h1

h0

13

DRAFT


6-

23

TABLE 6.2: SUMMARY OF FOUR BOLT EXTENDED STIFFENED END PLATE DESIGN STRENGTH 555 556


Case 1 (de <s) Case 2 (de > s)

End Plate


Case 1 (de < s)

[ ])pd(h)sp(hg2

s21

p1h

s1

p1h

2b

Y ofe0if1of

0if

1p

\p

++++

++

+=

Case 2 (de > s)

( ) ( )[ ]of0if1of

0if

1p

p pshsphg2

p1

s1h

s1

p1h

2b

Y

++++

++

+=


Bolt Rupture ( )1otnp hhP2M += φφ φ = 0.75

557

tp

g

tw

bp

s

tfpfi

pfo

de

h0

h1

tp

bp

tw

g

pfo

pfitf

s

s

h1

h0 Mnp

2 Pt

2 Pt

h0h1

14

DRAFT


6-

24

TABLE 6.3: SUMMARY OF EIGHT BOLT EXTENDED STIFFENED END PLATE DESIGN STRENGTH 557 558


Case 1 (de < s) Case 2 (de > s)

End Plate


Case 1 (de < s)

gp4p3sh

4pph

4p3ph

4pdh

g2

s1h

p1h

p1h

d21h

2b

Y 2b

b4

bi,f3

bof2

be14

if3

of2

e1

pp +

+

++

++

++

++

+

+

+

=

Case 2 (de > s)

gp4p3sh

4pph

4p3ph

4psh

g2

s1h

p1h

p1h

s1h

2b

Y 2b

b4

bif3

bof2

b14

if3

of21

pp +

+

++

++

++

++

+

+

+

=


Bolt Rupture ( )4321tnp hhhhP2M +++= φφ φ = 0.75

559

tp

tw

g

de

pfo

pfitf

s

h4h3

h2h1

pb

pb

bp

h1 h2h3

h4

tp

tw

g

spb

pfi

pfo

pb

s

tf

bp

Mnp

2 Pt

2 Pt

2 Pt

2 Pt

h4h3

h2h1

15


25

TABLE 6.4: SUMMARY OF FOUR BOLT EXTENDED COLUMN FLANGE STRENGTH 559 560

Unstiffened Column Flange Geometry and Yield Line Pattern Stiffened Column Flange Geometry and Yield Line Pattern

Unstiffened Column Flange

c2fcycbcf Y t FM φφ =

2g

2c

4csh

4c3sh

g2

s1h

s1h

2b

Y2

0101fc

c +

+

++

++

+

=

gb21s fc = φb = 0.90

Stiffened Column Flange


( ) ( )[ ]os0is1os

0is

1fc

c pshpshg2

p1

s1h

p1

s1h

2b

Y

++++

++

+=

gb21s fc = φb = 0.90 Note: If psi > s, use psi = s

561

h1

h0

c

s

s

bfc

g

twc

tfc

ts

pso

psi

s

s

h0h1

bfc

tfc

twc

g

16


26

TABLE 6.5: SUMMARY OF EIGHT BOLT EXTENDED STIFFENED COLUMN FLANGE DESIGN STRENGTH 561 562

Unstiffened Column Flange Geometry and Yield Line Pattern Stiffened Column Flange Geometry and Yield Line Pattern

Unstiffened Column Flange


( )2gsh

2c

2ph

4c

2phs

2cph

g2

s1h

s1h

2b

Y 4b

3b

2b141fc

c +

+

++

++

+++

+

=

gb21s fc = φb = 0.90

Stiffened Column Flange


gp4p3sh

4pph

4p3ph

4psh

g2

s1h

p1h

p1h

s1h

2b

Y 2b

b4

bis3

bos2

b14

is3

os21

fcc +

+

++

++

++

++

+

+

+

=

gb21s fc = φb = 0.90 Note: If psi > s, use psi = s

563 564 565

twc

g

tfc

h1

h4h3

h2

c

pb

pb

s

s

bfc

s

s

psi

psots

g

twc

tfc

bfc

h4h3

h2h1

pb

pb

17

DRAFT


N-1

APPENDIX N 1 NONDESTRUCTIVE TESTING 2

3 N1. NDT Personnel 4 5 Nondestructive testing of welds shall be performed using NDT technicians qualified as follows: 6 7 N1.1 General 8 9 Nondestructive testing personnel shall be qualified in accordance with their Employer’s Written 10 Practice which shall meet or exceed the criteria the American Society for Nondestructive 11 Testing, Inc. Recommended Practice SNT-TC1A or CP-189, Standard for the Qualification and 12 Certification of Nondestructive Testing Personnel. 13 14 N1.2 Ultrasonic Testing Technicians 15 16 Ultrasonic Testing for QA may be performed only by UT technicians certified as Level II by 17 their employer, or certified as ASNT Level III through examination by the ASNT, and certified 18 by their employer. If the Engineer approves the use of flaw sizing techniques, UT technicians 19 shall also be qualified for the specified flaw sizing technique. 20 21 N1.3 Magnetic Particle and Dye Penetrant Testing Technicians 22 23 Magnetic Particle Testing (MT) and Dye Penetrant Testing for QA may be performed only by 24 technicians certified as Level II by their employer, or certified as ASNT Level III through 25 examination by the ASNT, and certified by their employer. 26 27 N2. NDT Procedures 28 29 Nondestructive testing of welds shall be performed using nondestructive methods conforming to 30 AWS D1.1. 31 32 Ultrasonic testing shall be performed according to the procedures prescribed in AWS D1.1 33 Section 6, Part F, following a written procedure containing the elements prescribed in paragraph 34 K3 of Annex K. Section 6, Part F procedures shall be qualified using weld mock-ups having 35 0.059 in. (1.5 mm) diameter side drilled holes similar to Annex K, Figure K. 36 37 Magnetic Particle Testing shall be performed using the Yoke Method in accordance with a 38 written practice that conforms to ASTM E709. 39 40 Dye Penetrant Testing shall be in accordance with ASTM E165. 41 42 N3. NDT Acceptance Criteria 43 44

DRAFT


N-2

Acceptance Criteria for welds shall be as follows: 45 a. MT and PT acceptance criteria shall be in accordance with AWS D1.1 Section 6.10. 46 b. Ultrasonic Testing acceptance criteria shall be in accordance with AWS D1.1 Section 6.13.1. 47 48 N4. Required NDT 49 50 N4.1 CJP Groove Welds 51 52 Ultrasonic Testing shall be performed on 100% of CJP groove welds in materials 5/16 in. (8 53 mm) thick or greater. Ultrasonic Testing in materials less than 5/16 in. (8 mm) thick is not 54 required. Magnetic particle inspection shall be performed on 25 percent of all beam-to-column 55 CJP groove welds. 56 57 N4.2 Base Metal for Lamellar Tearing 58 59 After joint completion, base metal thicker than 1.5 in. (38 mm) loaded in tension in the through 60 thickness direction in tee and corner joints, when the complete joint penetration groove weld is 61 greater than ¾ in. (19 mm) shall be ultrasonically tested for discontinuities behind and adjacent 62 to such welds. Any base metal discontinuities found within t/4 of the steel surface shall be 63 accepted or rejected on the basis of criteria of AWS D1.1 Table 6.2. 64 65 N4.3 Beam Copes and Access Holes 66 67 Magnetic Particle or Penetrant Testing shall be performed on the thermally cut surfaces of beam 68 copes and access holes in rolled shapes with flanges thicker than 1.5 in. (38 mm) and built-up 69 shapes with web material thickness greater than 1.5 in. (38 mm). 70 71 N4.4 k-Area 72 73 After welding is performed in the k-area, the web shall be tested for cracks using magnetic 74 particle testing (MT). The k-area shall be defined as the region within 1 in. (38 mm) of the k-75 dimension on the web. The MT inspection area shall include the k-area base metal within 3 in. 76 (76 mm) of the weld. The MT shall be performed no less than 48 hours following completion of 77 the welding. 78 79 80 81 82

DRAFT


N-3

N4.5 Base Metal Repairs 83 When repair welding within the protected zone has been performed at the following 84 locations, repair welds and adjacent areas shall be tested for cracks using Magnetic 85 Particle Testing: 86 i. Reduced Beam Section cut profiles 87 ii. Weld access holes 88 iii. Weld tab removal sites 89 90 N5. Reduction in NDT Frequency 91 92 N5.1 Reduction of Percentage of Ultrasonic Testing 93 The amount of Ultrasonic Testing is permitted to be reduced if approved by the Engineer 94 of Record and the Authority Having Jurisdiction. The nondestructive testing rate for an 95 individual welder or welding operator may be reduced to 25 percent, provided the reject 96 rate is demonstrated to be 5 percent or less of the welds tested for the welder or welding 97 operator. A sampling of at least 40 completed welds for a job shall be made for such 98 reduction evaluation. Reject rate is the number of welds containing rejectable defects 99 divided by the number of welds completed. For evaluating the reject rate of continuous 100 welds over 3 ft (0.914 m) in length where the effective throat thickness is 1 in. (25 mm) 101 or less, each 12 in. (305 mm) increment or fraction thereof shall be considered as one 102 weld. For evaluation the reject rate on continuous welds over 3 ft (0.914 m) in length 103 where the effective throat thickness is greater than 1 in. (25 mm), each 6 in. (645 mm) of 104 length or fraction thereof shall be considered one weld. 105 106

DRAFT


Q-1

APPENDIX Q 1 QUALITY ASSURANCE PLAN REQUIREMENTS 2

3 Q1. General 4 5 The general requirements and responsibilities for a Quality Assurance Plan shall be in 6 accordance with the requirements of the Authority Having Jurisdiction 7 and the Engineer Of Record. 8 9 The Quality Assurance Plan shall include at a minimum: 10 11 i. Identification of the connections subject to the Plan 12 ii. Inspection requirements, including the frequency of inspection and type of inspection 13

necessary to establish that the construction is in conformance with this Standard and the 14 Contract Documents. 15

iii. Required Contractor Quality Control procedures. 16 iv. Whether the inspection is to be performed by QC or QA personnel 17 v. Structural Observation and other services to be performed by the Engineer or designee 18 vi. Requirements for inspection and structural observation records to be maintained and / or 19

submitted. 20 21 Where the Contractor’s QC has demonstrated the capability to perform some tasks this Plan 22 assigns to QA, modification shall be permitted. 23 24 Q2. Drawings 25 26 Q2.1 Contract Documents 27 28 The Contract Documents shall clearly indicate the work that is to be performed, and shall include 29 the following information, in accordance with the Connection Prequalification Requirements: 30 31 i. Which members and connections are part of the Seismic Load Resisting System 32 ii. The configuration of the connection 33 iii. Connection material specifications and sizes 34 iv. Locations of Demand Critical welds 35 v. Lowest Anticipated Service Temperature of the steel structure, if the structure is not 36

enclosed and maintained at a temperature of 50oF (10 oC) or higher 37

DRAFT


Q-2

vi Shape of weld access holes, if a special shape is required 38 vii. Locations where backup bars are required to be removed 39 viii. Locations where supplemental fillet welds are required when backing is permitted 40

to remain in place 41 ix. Locations where fillet welds are used to reinforce groove welds or to improve 42

connection geometry 43 x. Locations where weld tabs are required to be removed 44 xii. Locations of joints or groups of joints in which a specific assembly order, welding 45

sequence, welding technique or other special precautions are required 46 xiii. Location of the Protected Zone 47 xv. Nondestructive testing (NDT) requirements 48 xvi. Bolt hole fabrication requirements, if specified in the Prequalification 49 xvi. Requirements additional to those defined in the description of the connection 50

configuration. 51 52 Q2.2 Shop Drawings 53 54 Shop Drawings shall include the following information: 55 56

1. Access hole dimensions, surface profile and finish requirements 57 2. Locations where backing bars are to be removed 58 3. Locations where weld tabs are to be removed 59 4. Demand Critical welds 60 5. Protected Zone 61 6. NDT requirements to be performed by the fabricator, if any 62 7. Bolt hole fabrication requirements, if specified in the Prequalification 63 8. Locations where supplemental fillet welds are required when backing is permitted 64

to remain in place 65 9. Locations where fillet welds are used to reinforce groove welds or to improve 66

connection geometry 67 10. Locations of joints or groups of joints in which a specific assembly order, welding 68

sequence, welding technique or other special precautions are required 69 11. Requirements additional to those defined in the description of the connection 70

configuration. 71 72 Q2.3 Erection Drawings 73 74 Erection drawings shall include the following information: 75 76 i. Locations where backing bars are to be removed 77 ii. Locations where supplemental fillet welds are required when backing is permitted 78

to remain 79 iii. Locations where weld tabs are to be removed 80 iv. Demand Critical Welds 81 v. Protected Zone 82 83

DRAFT


Q-3

Q2.4 Contractor’s Submittals 84 85 The following documents shall be submitted for review by the Structural Engineer of 86 Record prior to fabrication or erection, as applicable: 87 88 i. Shop drawings (see Q2.2) 89 ii. Erection drawings (see Q2.3) 90 iii. Welding Procedure Specifications (WPS) and additional submittals, as described 91

in Q2.5 92 93 The following documents shall be available for review by the ODRD prior to fabrication 94 or erection, unless specified to be submitted. 95

96 i. Material test reports, including structural steel, bolts, shear connectors, and 97

welding materials as described in Q2.5 98 ii. Inspection procedures (see Appendix Y) 99 iii. Nonconformance procedure 100 iv. Material control procedure 101 v. Bolt installation procedure 102 vi. Welding Personnel Qualification Records (WPQR), including any supplemental 103

testing requirements 104 vii. Inspector qualifications (see Appendix Y) 105 106 Q2.5 Contractor’s Welding Submittals 107 108 The Contractor welding submittals shall include: 109 110 i. Copies of all Manufacturer’s typical Certificates of Conformance for all 111

electrodes, fluxes and shielding gasses to be used. Certificates of Conformance 112 shall satisfy the applicable AWS A5 requirements. 113

ii. Applicable manufacturer’s certifications that the product meets the requirements 114 for demand critical welds, as applicable. Should the welding material 115 manufacturer not supply such supplemental certifications, the Contractor shall 116 have the necessary testing performed and provide the applicable test reports. 117

iii. Manufacturer’s product data sheets for all welding material to be used. The data 118 sheets shall describe the product, limitations of use, recommended or typical 119 welding parameters, and storage and exposure requirements, including baking, if 120 applicable. 121

iv. WPSs to be used on the project. The WPS shall specify all applicable essential 122 variables of AWS D1.1 and the following, as applicable: 123

124 (1) Power source (constant current or constant voltage) 125 126 (2) Electrode manufacturer and trade name, if FCAW 127 128

DRAFT


Q-4

Q2.6 Quality Assurance Agency Submittals 129 130 The Quality Assurance Agency shall submit to the Authority Having Jurisdiction, 131 Engineer of Record, and Owner or Owner’s designee the following documents: 132 133 i. QA Agency’s Written Practices for the monitoring and control of the Agency’s 134

operations. Written Practice shall include: 135 136

(1) the Agency’s procedures for the selection and administration of inspection 137 personnel, describing the training, experience and examination requirements for 138 qualification and certification of inspection personnel 139

140 (2) the Agency’s inspection procedures, including general inspection, material 141 controls, and visual welding inspection 142 143

ii Qualifications of management and QA personnel designated for the project. 144 iii Qualification records for Inspectors and NDT technicians designated for the 145

project 146 iv. NDT procedures and equipment calibration records for NDT to be performed and 147

equipment to be used for the project 148 v. Daily or weekly inspection reports 149 vi. Nonconformance reports 150 151 Q2.7 Pre-Fabrication / Pre-Erection Meeting 152 153 The Engineer, Quality Assurance Agency personnel supervising Quality 154 Assurance work, and Contractor’s personnel supervising operations and Quality Control 155 work shall hold a Pre-Fabrication and Pre-Erection Conference to review operations and 156 inspection requirements. 157 158 159

DRAFT


Y-1

APPENDIX Y 1 VISUAL INSPECTION 2

3 4 Y1. Visual Inspection Personnel 5 6 Visual inspections shall be conducted by qualified personnel, as follows: 7 8 Y1.1 QC Welding Inspectors 9 10 QC welding inspection personnel shall be Associate Welding Inspectors (AWI) or higher, or 11 otherwise qualified under the provisions of AWS D1.1 Section 6.1.4, and to the satisfaction of 12 the Contractors QC plan by the fabricator/erector. 13 14 Y1.2 QA Welding Inspectors 15 16 QA welding inspectors shall be Welding Inspectors (WI), or Senior Welding Inspectors (SWI), 17 as defined in ASTM B5.1, Standard for the Qualification of Welding Inspectors, except AWIs 18 may be used under the direct supervision of WIs, on site and available when weld inspection is 19 being conducted. 20 21 22 Y2. Visual Inspection Tasks and Documentation 23 24 Visual inspections shall be conducted in accordance with a written practice, as provided in the 25 following tables: 26 27 Visual Inspection points and frequencies of Quality Assurance (QA) and Quality Control (QC) 28 tasks and documentation for the connection shall be as follows: 29 30 Observe (O) - The inspector shall observe these functions on a random, daily basis. 31 32 Perform (P) - These inspections shall be performed prior to the final acceptance of the 33 item. Where an inspection task is noted to be performed by both QC and QA, performance of the 34 task by one party, witnessed by the other, is acceptable. 35 36 Document (D) – The inspector shall prepare reports indicating that the work has been performed 37 in accordance with the Contract Documents. The report need not provide detailed measurements 38 for joint fit-up, WPS settings, completed welds, or other individual items listed in the Tables in 39 Sections Q5.1, Q5.3 or Q5.4. For shop fabrication, the report shall indicate the piece mark of the 40 piece inspected. For field work, the report shall indicate the reference grid lines and floor or 41 elevation inspected. Work not in compliance with the Contract Documents and whether the 42 noncompliance has been satisfactorily repaired shall be noted in the inspection report. 43 44

DRAFT


Y-2

45 Y2.1 Visual Inspection Tasks Before Welding 46 47

QC QA Task

Task Doc

Task

Doc

Material identification (Type/Grade) O - O - Fit-up of groove welds (including joint geometry)

• Joint preparation • Dimensions (alignment, root opening, root face, bevel) • Cleanliness (condition of steel surfaces) • Tacking (tack weld quality and location) • Backing type and fit (if applicable)

P/O

-

O

-

Fit-up of fillet welds • Dimensions (alignment and gap at the root) • Cleanliness (condition of steel surfaces) • Tacking (tack weld quality and location)

O

-

O

-

48 49

DRAFT


Y-3

Y2.2 Visual Inspection Tasks During Welding 49

QC

QA Task

Task

Doc

Task

Doc

WPS followed

• Settings on welding equipment • Travel speed • Welding materials • Shielding gas type / flow rate • Preheat applied • Interpass temperature maintained (min / max) • Proper position (F, V, H, OH) • Intermix of filler metals avoided unless approved

O

-

O

-

Use of qualified welding personnel

O

-

O

-

Control and handling of welding consumables

• Packaging • Exposure control

O

-

O

-

Environmental conditions

• Wind speed within limits

• Precipitation and temperature

O

-

Welding techniques

• Interpass and final cleaning • Each pass within profile limitations • Each pass meets quality requirements

O

-

O

-

Tack welds do not crack during welding

O

O

50 51

DRAFT


Y-4

Y2.3 Visual Inspection Tasks After Welding 51

QC

QA Task

Task

Doc

Task

Doc

Welds cleaned

O

-

O

-

Welder identification marks legible

O

-

O

-

Verify size length, and location of welds

O

-

O

-

Visually inspect welds to acceptance criteria

• Crack prohibition • Weld / base-metal fusion • Crater cross-section • Weld profiles • Weld size • Undercut • Porosity

P

D

P

D

Placement of reinforcement fillets (when required)

P

D

P

D

Backing bars and weld tabs removed (when required)

P

D

P

D

Repair activities

P

D

P

D

52

DRAFT


Y-5

Y2.4 Other Inspections 52

QC

QA Task

Task

Doc

Task

Doc

RBS requirements, if applicable

• contour and finish • dimensional tolerances

P

-

P

-

Configuration and finish of access holes

P

-

P

-

Finish of weld tab removal sites

P

-

P

-

Protected zone – no holes and unapproved attachments made by the Contractor

P

-

P

-

53 54 Y2.5 Inspection Tasks Prior To High Strength Bolting 55 56

QC QA Task Task Doc Task Doc Proper bolts are selected for the joint detail O - O - Proper bolting procedure is selected for joint detail O - O - Connecting elements are fabricated properly, including the appropriate faying surface condition

O - O -

Pre-installation verification testing is conducted for fastener assemblies and methods used

P D O D

Proper storage is provided for bolts, nuts, washers, and other fastener components

O - O -

57

DRAFT


Y-6

Y2.6 Inspection Tasks During High Strength Bolting 57

QC

QA Task

Task

Doc

Task

Doc

Fastener assemblies are placed in all holes and washers (if required) are properly positioned

O

-

O

-

Joint is brought to the snug tight condition prior to the pretensioning operation

O

-

O

-

Fastener component not turned by the wrench is prevented from rotating

O

-

O

-

Bolts are pretensioned progressing systematically from

O

-

O

-

58 Y2.7 Inspection Tasks After High Strength Bolting 59

QC

QA

Task

Task

Doc

Task

Doc

Document accepted and rejected connections.

P

D

P

D

60 61

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