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D1.8 Seismic Supplement Welding Manual
A General Overview of AWS D1.8 Structural Welding Code - Seismic Supplement
Structural Welding Code
Seismic Supplement
www.lincolnelectric.com
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2 D1.8 Seismic Supplement Welding Manual Introduction Table of Contents Lincoln Electric, the worldwide leader in welding Introduction........................................................2 equipment and consumables, is proud to present this manual to the American Welding Society’s Background........................................................4 D1.8 Seismic Supplement. Purpose.and.Use.................................................6 Because welding is essential in the construction of
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D1.8 Seismic Supplement Welding Manual 3 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 inf
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4 D1.8 Seismic Supplement Welding Manual 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 res
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D1.8 Seismic Supplement Welding Manual 5 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 Provision
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6 D1.8 Seismic Supplement Welding Manual 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
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D1.8 Seismic Supplement Welding Manual 7 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.
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8 D1.8 Seismic Supplement Welding Manual 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, w
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D1.8 Seismic Supplement Welding Manual 9 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 typ
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10 D1.8 Seismic Supplement Welding Manual 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 belo
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D1.8 Seismic Supplement Welding Manual 11 Significant revisions in the second edition are listed below. For more revisions please see pages vii-viii in the AWS D1.8/D1.8M:2009. Figures 4.1 and 4.2 – New figures added to illustrate detail of the transition of butt joints for unequal thicknesses. Subclause 6.3.2 – Clarified and corrected diffusible hydrogen requirements for filler metals. Subclause 6.3.6 – Modified to disallow exemptions from heat input envelope and classification lot
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12 D1.8 Seismic Supplement Welding Manual Structural.Detailers. Table 2 provides a list of references to specific D1.8 code provisions of particular interest to the structural detailer: TABLE 2: SPECIFIC D1.8 CODE PROVISIONS Structural.Detail D1.8.Coverage Access Holes 1.2.1(9), 6.9 Backing—Removal 1.2.1(5), 6.7, 6.8 Backing—Remaining in Place 1.2.1(6), 6.12 Contouring Fillet Welds 1.2.1(8), 6.8 Corner Clips 4.1 Demand Critical Welds 1.2.1(4), 3.2 End Dams 6.11 k-Area Detailing 3.6, 4.1 Prote
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D1.8 Seismic Supplement Welding Manual 13 a) the weld is Demand Critical; and b) the weld joins the beam bottom flange to a column flange; and c) the weld must be made through a weld access hole in the beam web. As mentioned above, the qualification of welders in accordance with Annex D is only required when all three of these preceding conditions are part of the production weld. If any one is not present (i.e. a production weld that is not made through a weld access hole) this qualificatio
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14 D1.8 Seismic Supplement Welding Manual Welding Procedure Specifications (WPSs) A welding procedure specification is “a document providing the required welding variables for a specific application to assure repeatability by properly trained welders and welding operators” according to AWS A3.0 Standard Terms and Definitions. AWS D1.1 requires WPSs to be documented (see D1.1 subclause 3.1, 4.6). Under D1.1, WPSs may be either prequalified or qualified by test, and both types of WPSs may be u
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D1.8 Seismic Supplement Welding Manual 15 From a practical perspective, it is expected that most contractors doing D1.8 work will use the same filler metals for both Demand Critical welds and other welds that are part of the seismic force resisting system. The effort required to segregate the different filler metals for different joints, and the potential consequences of inadvertently using the wrong filler metal to make a Demand Critical weld, suggest that it is prudent to use the same mat
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16 D1.8 Seismic Supplement Welding Manual Cooling rates are a function of several variables, including heat input. High heat input levels result in slower cooling rates, whereas low heat input levels increase cooling rates. D1.8 requires that the filler metals to be used in production first be evaluated in tests run at high and low levels of heat input, that is, under slow and fast cooling rates. Production welding WPSs are then permitted to use a wide range of variables, providing the calcu
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D1.8 Seismic Supplement Welding Manual 17 For FCAW-G and FCAW-S electrodes used to make Demand Critical welds, exposure of the filler metal after it has been removed from protective packaging is required to be controlled. In the absence of test data indicating otherwise, exposure is limited to 72 hours. Tests can be performed in accordance with Annex E of D1.8, permitting this exposure time to be extended. Overexposed electrodes may be dried in accordance with the electrode manufacturer’s
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18 D1.8 Seismic Supplement Welding Manual Inspectors. The Inspector’s role with respect to D1.8 is no different than the role as defined by AWS D1.1, namely to ensure that materials and workmanship meet the requirements of the code and contract documents. This is done by performing inspection as necessary prior to assembly, during assembly, during welding, and after welding. All welds are subject to visual inspection, and depending on contract documents, nondestructive testing may also be re
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D1.8 Seismic Supplement Welding Manual 19 Regarding Structural Details Ensure that weld access holes are properly prepared. See D1.8, clause 6.9. Ensure that weld tabs and backing have been removed, when required. See D1.8, clause 6.7, 6.10. Regarding the Protected Zone Ensure that no unauthorized welds or attachments have been added. See D1.8, clause 6.15. Ensure that no unacceptable notches or gouges are in the protected zone. See D1.8, clause 6.15. Ensure that repairs in the protect
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20 D1.8 Seismic Supplement Welding Manual Lincoln Electric Products The Lincoln Electric Company offers a broad range of filler metals capable of meeting the requirements of AWS D1.8 Seismic Welding Supplement. Whether your choice of welding process is SMAW, FCAW-S, FCAW-G, GMAW, GMAW-C or SAW, Lincoln manufactures and offers consumables that will satisfy D1.8 requirements for nearly every application. To save our customers time and money, Lincoln has already performed various tests require
