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D1.8 Seismic Supplement Welding Manual
A General Overview of AWS D1.8 Structural Welding Code - Seismic Supplement
www.lincolnelectric.com Structural Welding Code
Seismic Supplement
2D1.8 Seismic Supplement Welding Manual
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Introduction
Lincoln Electric, the worldwide leader in welding
equipment and consumables, is proud to present
this manual to the American Welding Society’s
D1.8 Seismic Supplement.
Because welding is essential in the construction of
the vast majority of buildings, innovative welding
techniques are and will continue to be critical to
safer, sounder structures in seismic zones.
The leader in seismic welding solutions is
Lincoln Electric.
Our leadership comes from our history; for over
100 years Lincoln Electric has been at the forefront
of welding technology. It comes from our people;
Duane Miller, Lincoln’s Manager of Engineering
Services, chaired the D1.8 committee. And it comes
from our products; we have consumables and
welding solutions designed help you meet new
and evolving requirements.
To assist structural fabricators, erectors, inspectors
and specifying engineers, Lincoln Electric has
created this D1.8 Seismic Supplement Welding
Manual as an aid to understand seismic welding
requirements and the Lincoln Electric consumables
tested to meet the AWS D1.8 requirements.
This update to Lincoln Electric’s D1.8 Seismic
Supplement Welding Manual is just one more way
Lincoln sets the standard for the welding industry.
That is why, for the most reliable welds in seismic
zones, the structural fabrication industry chooses
Lincoln.
Table of Contents
Introduction .......................................................2
Background .......................................................4
Purpose and Use ................................................6
Specifications ....................................................6
Overview ............................................................8
Differences from FEMA 353..............................10
A User’s Guide To AWS D1.8 .............................11
Engineers .....................................................11
Structural Detailers .....................................12
Fabricators and Erectors .............................12
Inspectors ....................................................18
References ........................................................19
Lincoln Electric Products .................................20
Exposure Testing ..............................................22
Appendices .......................................................24
A: D1.8 Certifications ..................................25
B: Intermix Testing ......................................40
C: Lot Control Alternative Documentation ..42
Note: Please refer to the Safety References Section on page 18 for more information on certificates, booklets and general safety practices.
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Customer Assistance Policy
The Lincoln Electric Company sells welding consumables and related equipment. On occasion, purchasers
may ask the Company for advice or information about the use of these products. As a customer
accommodation, our employees respond without charge based on information provided and their knowledge
of Lincoln Electric products. Lincoln Electric offers no guarantee or warranty, and assumes no liability, with
respect to such information or advice; nor does it assume any responsibility for updating or correcting any
such information or advice once it is given; nor does its provision of information or advice create, expand or
alter any warranty with respect to the sale of the Company’s products. Lincoln Electric expressly disclaims
any warranty of any kind, including any warranty of fitness for any particular purpose, with respect to such
information or advice. The selection and use of products sold by Lincoln Electric is solely within the control
of, and remains the sole responsibility of, the customer.
Document Updates
The information contained in this document is believed to be accurate at the time of printing and is subject
to change as additional information and data becomes available. Examples of such modifications include,
but are not limited to, the incorporation of additional product data and alterations due to AWS D1.8 updates.
The reader is encouraged to check the Lincoln Electric website for updates (www.lincolnelectric.com). This
manual references other documents not published by Lincoln Electric. Those documents are also subject to
change, and the reader is encouraged to check the latest edition of referenced documents for any changes
that might affect the content of this manual.
This document is an update to Lincoln Electric’s 2008 D1.8 Seismic Supplement Welding Manual and
reflects changes made to the AWS D1.8 Structural Welding Code - Seismic Supplement in 2009.
4D1.8 Seismic Supplement Welding Manual
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Background
In January 1994, the Northridge, California earthquake caused unexpected damage to a number of welded
steel-framed buildings in the greater Los Angeles area. The Federal Emergency Management Agency (FEMA)
funded a variety of investigations that sought to address both the immediate and long-term needs related to
solving the performance problems associated with welded steel moment-frame connections. Several
documents were published as a result of these investigations, including Recommended Specifications and
Quality Assurance Guidelines for Steel Moment-Frame Construction for Seismic Applications (FEMA 353)1.
FEMA 353 discusses what has come to be known as the “Pre-Northridge Connection” and concluded that
“…the typical moment-resisting connection detail employed in steel moment-frame construction prior to
the 1994 Northridge earthquake… had a number of features that rendered it inherently susceptible to brittle
fracture. These included the following:
The most severe stresses occurred in the connection
“Wildcat” welding position
Connection detail makes it hard to inspect
Significant flexural stresses on the beam flange at the column face
Weld access hole geometry
High restraint
Weak panel zones
The report continued on to say “…additional conditions contributed significantly to the vulnerability of
connections...” including:
Low toughness FCAW-S welding the consumables
Low redundancy
Matching beam and column strength
FEMA 353 then proposed a variety of recommendations and quality assurance guidelines that addressed
various topics, including:
Overall structural design
Connection design
Connection details
Materials, including both base metal and weld metal
Workmanship
Inspection
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The provisions within FEMA 353 were not binding but did become mandatory when incorporated into
Contract Documents.
While the FEMA recommendations were being drafted, the American Institute of Steel Construction (AISC)
and the American Welding Society (AWS) began to evaluate their specifications and codes and revise them to
incorporate the post-Northridge research on steel connections. AISC issued a variety of interim updates to the
Seismic Provisions, as well as complete new editions of the standard. Contained in these AISC documents are
a variety of welding-related provisions. The primary focus of the AISC Seismic Provisions, however, is on the
design of structures intended to resist seismically induced loads, including the design of the connections and
thus, some welding-related provisions.
During this same time period, the AWS D1 Structural Welding Committee formed a new subcommittee D1L,
charged with the responsibility of developing a new standard to address welding-related requirements for
buildings designed to resist seismically induced loads. Ultimately, this subcommittee produced and the D1
committee approved, AWS D1.8 Structural Welding Code-Seismic Supplement2.
Many of the changes made to the AISC and AWS standards were the direct result of the work sponsored by
FEMA. Some of the provisions directly reflect the recommendations of FEMA 353. In other cases, the initial
recommendations were modified by the AISC and AWS consensus committees. Finally, some FEMA 353
recommendations deemed to be unnecessary by the AISC or AWS committees were eliminated.
The FEMA-sponsored effort focused on moment-resisting connections, whereas the AISC and AWS
documents addressed other Seismic Force Resisting Systems (SFRS), thus justifying some additional
provisions that were not contained within FEMA 353. Therefore, these latest documents do more than
simply incorporate FEMA 353 provisions directly into AISC or AWS specifications.
AWS D1.8 was approved in 2005 and first printed and distributed in 2006. In 2009 the AWS published the
second edition of the AWS D1.8/D1.8M, Structural Welding Code - Seismic Supplement. Subsequent revisions
have also been made to this document.
6D1.8 Seismic Supplement Welding Manual
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The Purpose and Use of This Manual
This manual has been prepared by The Lincoln Electric Company to assist our customers in complying
with the requirements of AWS D1.8. Additionally, a summary of important provisions is included to assist
engineers, steel detailers and inspectors. This manual does not address every provision of D1.8, and tends
to discuss only the general condition that will typically be encountered, versus unique situations that may
arise. Readers of this manual are encouraged to obtain and review a copy of AWS D1.8, which can be
purchased through the AWS (www.awspubs.com).
Reference to AISC specifications is also made throughout this manual. Copies of pertinent AISC documents
can be downloaded from the AISC website (www.AISC.org) for free, or can be purchased in printed form.
This manual does not in any respect act as a substitute for or in compliance with AWS D1.8 or AISC
specifications. Should any conflict exist between the content of this manual and these referenced
specifications, the documents as published by AISC or AWS should be taken as the authoritative reference.
To assist the user, applicable provisions as contained in D1.8:2009 are referenced at the end of paragraphs
describing the requirements.
Specifications
AWS D1.8 and Other Specifications
AWS D1.8 alone cannot be used to design, fabricate, erect and inspect a structure intended to
resist seismic loadings. Of necessity, D1.8 is used in conjunction with other construction documents,
specifications and codes. Importantly, D1.8 does not contain all the welding-related requirements.
The general interaction of D1.8 and welding-related provisions is outlined below.
AWS D1.8 and AISC Specifications
Three AISC specifications may apply to a project where seismic resistance is required: AISC 360
Specifications for Structural Steel Buildings3, AISC 341 Seismic Provisions for Structural Steel Buildings4,
and AISC 358 Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic
Applications5. These three documents will be referred to as AISC Specifications, AISC Seismic Provisions
and AISC Prequalified Connections, respectively, throughout the remainder of this manual.
The relationship between AWS D1.8 and the AISC Specifications is no different than that between the AISC
Specifications and AWS D1.1.
There is significant interaction between the AISC Seismic Provisions and D1.8. Typically, AISC Seismic
Provisions specify where and when certain welding related provisions apply, while AWS D1.8 will specify
how such provisions are implemented. For example, AWS D1.8 does not specify when steel backing must be
removed from a connection. However, when backing removal is required by AISC specifications, AWS D1.8
specifies how the backing is to be removed.
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The AISC’s Prequalified Connections document prescribes prequalified structural connections
(beam-to-column connections, for example, not to be confused with AWS prequalified welding procedure
specifications, or with prequalified joint details). As part of connection prequalification, welding-related
issues such as backing removal, weld tab removal, weld metal properties and inspection requirements
are prescribed.
AWS D1.8 and Other AWS Standards
AWS D1.8 supplements AWS D1.1 Structural Welding Code—Steel6. D1.8 does not replace D1.1, and except
as modified by D1.8, all of D1.1 still applies when D1.8 is specified. See D1.8, clause 1.1.
AWS D1.8 is intended to be used on steel structures, where D1.1 applies. D1.8 should not, for example,
be used to supplement AWS D1.6 Structural Welding Code—Stainless Steel7. See D1.8, clause 1.3.
AWS D1.8 references the AWS A5 Filler Metal Specifications. Of particular interest is the reference to AWS
A5.20: 20058 since this specification has incorporated a new supplemental electrode designator, the “-D”
suffix. This suffix reflects a concept contained in both FEMA 353 and D1.8, that of high-low heat input
testing, discussed later in this manual. It is expected that future editions of AWS A5.29 will include a
similar supplemental designator.
AWS D1.8 and Contract Documents
Contract Documents are used to specify requirements that may modify provisions contained within codes.
In the case of D1.8, Contract Documents play an especially important role, since many provisions typically
required for buildings designed to resist seismic loading are not specified in D1.8. Rather, D1.8 requires that
when such provisions are to apply, the Engineer must specify them in the Contract Documents. Thus,
Contract Documents may be used to “customize” requirements around a specific project. The implication is
that one project governed by D1.8 may have significantly different requirements from another, because the
Contract Documents for the two projects are different.
AWS D1.8 and FEMA 353
D1.8 and FEMA 353 are totally separate documents, and it would be impossible to impose both provisions to
govern a project without creating significant conflict and contradictions. However, qualifications and various
tests done to meet the criteria of FEMA 353 may be used to meet similar or identical requirements in D1.8.
Accordingly, such transfer of results is encouraged in D1.8, subject to the Engineer’s approval. For example,
the welder qualification test as prescribed in FEMA 353, Appendix B is similar to that specified in D1.8 Annex
D, and the D1.8 commentary specifically encourages the Engineer to accept previous welder qualification
testing done to FEMA 353 requirements.
8D1.8 Seismic Supplement Welding Manual
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Overview of D1.8
Content
FEMA 353 identified a variety of factors that made the pre-Northridge connection “…inherently susceptible
to brittle fracture...” and then listed variables that can be grouped into the broad categories of overall
structural design, connection design, connection details, materials, workmanship and inspection. While most
of the design-related issues are covered in AISC standards, D1.8 addresses connection details, materials,
workmanship and inspection issues.
These topics are covered in seven clauses as follows:
Clause 1 General Requirements
Clause 2 Reference Documents
Clause 3 Definitions
Clause 4 Welded Connection Details
Clause 5 Welder Qualification
Clause 6 Fabrication
Clause 7 Inspection
Following these clauses are eight mandatory annexes as follows:
Annex A WPS Heat Input Envelope Testing of Filler Metals for Demand Critical Welds
Annex B Intermix CVN Testing of Filler Metal Combinations (where one of the filler metals is FCAW-S)
Annex D Supplemental Welder Qualification for Restricted Access Welding
Annex E Supplemental Testing for Extended Exposure Limits for FCAW Filler Metals
Annex F Supplemental Ultrasonic Technician Testing
Annex G Supplemental Magnetic Particle Testing Procedures
Annex H Flaw Sizing by Ultrasonic Testing
Annex I Guidelines for the Preparation of Technical Inquiries for the Structural Welding Committee
Finally, the document concludes with an extensive commentary that provides background material and
explains the Structural Welding Committee’s intent behind many of the provisions, as well as an index.
New Terminology
In a manner that has been coordinated with the applicable AISC committees, D1.8 utilizes some new
terminology. An understanding of these terms, officially defined in Clause 3: Terms and Definitions of D1.8,
is necessary to properly apply the code.
D1.8 Seismic Supplement Welding Manual
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The seismic load resisting system (SLRS) has been renamed as seismic force resisting system (SFRS) to be
consistent with terminology as revised in AISC seismic provisions and is “the assembly of structural elements
in the building that resists seismic loads.” These are the specific components in a building, such as columns,
beams, girders and braces, and the connections that join those components designed to resist seismic loads.
The SFRS does not typically include all the various structural elements in a building. See D1.8, clause 3.1.
Demand Critical welds are defined as “welds designated by the Engineer in Contract Documents, and
required to meet specific requirements of this code.” The most rigorous requirements of D1.8 are imposed
upon welds designated as “Demand Critical” (DC). See D1.8, clause 3.2.
The protected zone (PZ) is “that portion of a member of the SFRS… in which inelastic straining is anticipated
to occur….” Special limitations apply to attachments and fabrication practices associated with this zone.
See D1.8, clause 3.3.
It is important to note that D1.8 requires the Engineer to specify in contract documents the locations of
members that are part of the SFRS, which welds are Demand Critical, and the portion of members that
comprise the protected zone. Illustrative examples are contained in the commentary, although such
examples are not prescriptive or definitive. Contract documents should contain the specific requirements
applicable to a particular project. See D1.8, clause 1.2.1.
Three Kinds of Welds
When a structure is designed in accordance with the AISC Seismic Provisions, the welds on the building will
fit into three categories. The applicable code depends on the characteristics of the weld, as illustrated in the
following table:
Welds that are not on the SFRS as designated by the Engineer in contract documents are governed by
D1.1, and no special requirement for seismic considerations apply. Welds on the SFRS, but not designated
Demand Critical by the Engineer in contract documents, are governed by D1.8, but the additional provisions
for Demand Critical welds do not apply. Demand Critical welds (which, by definition, must be part of the
SFRS), are subject to all the applicable requirements of D1.8, as well as those additional provisions that
apply to Demand Critical welds. See D1.8, Commentary C-1.1.
TABLE 1: CODE COVERAGE FOR VARIOUS WELDS
Not Part of SFRS Part of SFRS
Not Demand Critical Demand Critical
Code Coverage AWS D1.1 AWS D1.8 AWS D1.8 DC
10 D1.8 Seismic Supplement Welding Manual
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Differences between FEMA 353 and AWS D1.8
As was previously mentioned, much of D1.8 was based upon recommendations contained within FEMA 353.
However, differences between the two documents exist. In many cases, FEMA 353 recommendations are
not contained in D1.8, but rather reside in the applicable AISC specification. In some situations, the AWS
consensus committee made deliberate decisions to approach the issue in a different manner.
Contained below is a partial listing of some of the significant differences:
The complicated and complex “weld categories” as contained in FEMA 353 have been replaced
with the three broader and simpler categories as outlined previously in Table 1.
Details of the WPS Heat Input Envelope Testing have been modified. In D1.8, the root pass can be
made in a single pass (versus a split pass, as required in FEMA 353), and the position of welding is
no longer an essential variable for this test. See D1.8, Annex A.
The Supplemental Welder Qualification test was expanded to include a testing procedure to address
welder qualification when steel backing is not used, including where copper or ceramic backing is
used, as well as when open root joints are used. See D1.8, Annex D.
Testing of the Supplemental Welder Qualification for Restricted Access Welding may be accomplished
by either radiographic testing (RT), ultrasonic testing (UT) or by mechanical testing (FEMA 353
permitted only mechanical testing or RT). Additionally, the typographical error as contained in FEMA
353 that called for 3/4 in. bend tests has been corrected in D1.8 to call for the intended 3/8 in. thick
bend specimens. See D1.8, Annex D.
D1.8 contains more definitive alternatives to lot tested filler metals. See D1.8, clause 6.3.8.
D1.8 specifically exempts the high/low heat envelope testing for the welding consumables when
SMAW is used with specific filler metals, and when GMAW is performed with solid electrodes.
See D1.8, clause 6.3.5.
D1.8 has extended the standard exposure period for FCAW electrodes from 24 to 72 hours.
See D1.8, clause 6.4.3.
A variety of other changes have been made, and a careful review of the two documents must be made if
the user is interested in a comprehensive comparison.
Differences between AWS D1.8/D1.8M:2005
and AWS D1.8/D1.8M: 2009
The second edition of the AWS D1.8/D1.8M, Structural Welding Code – Seismic Supplement features editorial
and technical revisions from the previous edition. These revisions are primarily refinements or clarifications
of information presented in the 2005 edition.
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