AWS D1.7/D1.7M:2010

An American National Standard

Guide for Strengthening and Repairing Existing Structures

AWS D1.7/D1.7M:2010

An American National Standard

Approved by the American National Standards Institute

July 1, 2009

Guide for Strengthening and Repairing Existing Structures

1st Edition

Prepared by the American Welding Society (AWS) D1 Structural Welding Committee

Under the Direction of the AWS Technical Activities Committee

Approved by the AWS Board of Directors

Abstract

This guide provides information on strengthening and repairing existing structures. Included are sections on weldability, evaluation of existing welds, testing and sampling, heat straightening, and damage repair.

550 N.W. LeJeune Road, Miami, FL 33126

International Standard Book Number: 978-0-87171-761-0

American Welding Society 550 N.W. LeJeune Road, Miami, FL 33126

© 2009 by American Welding Society

All rights reserved Printed in the United States of America

Photocopy Rights. No portion of this standard may be reproduced, stored in a retrieval system, or transmitted in any form, including mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner.

Authorization to photocopy items for internal, personal, or educational classroom use only or the internal, personal, or educational classroom use only of specific clients is granted by the American Welding Society provided that the appropriate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400; Internet:

<www.copyright.com>.

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Statement on the Use of American Welding Society Standards

All standards (codes, specifications, recommended practices, methods, classifications, and guides) of the American Welding Society (AWS) are voluntary consensus standards that have been developed in accordance with the rules of the American National Standards Institute (ANSI). When AWS American National Standards are either incorporated in, or made part of, documents that are included in federal or state laws and regulations, or the regulations of other govern- mental bodies, their provisions carry the full legal authority of the statute. In such cases, any changes in those AWS standards must be approved by the governmental body having statutory jurisdiction before they can become a part of those laws and regulations. In all cases, these standards carry the full legal authority of the contract or other document that invokes the AWS standards. Where this contractual relationship exists, changes in or deviations from requirements of an AWS standard must be by agreement between the contracting parties.

AWS American National Standards are developed through a consensus standards development process that brings together volunteers representing varied viewpoints and interests to achieve consensus. While the AWS administers the process and establishes rules to promote fairness in the development of consensus, it does not independently test, evalu- ate, or verify the accuracy of any information or the soundness of any judgments contained in its standards.

AWS disclaims liability for any injury to persons or to property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this standard. AWS also makes no guarantee or warranty as to the accuracy or completeness of any information published herein.

In issuing and making this standard available, AWS is neither undertaking to render professional or other services for or on behalf of any person or entity, nor is AWS undertaking to perform any duty owed by any person or entity to someone else. Anyone using these documents should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. It is assumed that the use of this standard and its provisions are entrusted to appropriately qualified and competent personnel.

This standard may be superseded by the issuance of new editions. Users should ensure that they have the latest edition.

Publication of this standard does not authorize infringement of any patent or trade name. Users of this standard accept any and all liabilities for infringement of any patent or trade name items. AWS disclaims liability for the infringement of any patent or product trade name resulting from the use of this standard.

Finally, the AWS does not monitor, police, or enforce compliance with this standard, nor does it have the power to do so.

On occasion, text, tables, or figures are printed incorrectly, constituting errata. Such errata, when discovered, are posted on the AWS web page (www.aws.org).

Official interpretations of any of the technical requirements of this standard may only be obtained by sending a request, in writing, to the appropriate technical committee. Such requests should be addressed to the American Welding Society, Attention: Managing Director, Technical Services Division, 550 N.W. LeJeune Road, Miami, FL 33126 (see Annex B). With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered. These opinions are offered solely as a convenience to users of this standard, and they do not constitute professional advice. Such opinions represent only the personal opinions of the particular individuals giving them. These individuals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations of AWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation.

This standard is subject to revision at any time by the AWS D1 Committee on Structural Welding. It must be reviewed every five years, and if not revised, it must be either reaffirmed or withdrawn. Comments (recommendations, additions, or deletions) and any pertinent data that may be of use in improving this standard are required and should be addressed to AWS Headquarters. Such comments will receive careful consideration by the AWS D1 Committee on Structural Welding and the author of the comments will be informed of the Committee’s response to the comments. Guests are invited to attend all meetings of the AWS D1 Committee on Structural Welding to express their comments verbally. Procedures for appeal of an adverse decision concerning all such comments are provided in the Rules of Operation of the Technical Activities Committee. A copy of these Rules can be obtained from the American Welding Society, 550

1. LeJeune Road, Miami, FL 33126.

   
   

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   Personnel

   
   

   AWS D1 Committee on Structural Welding

   D. K. Miller, Chair The Lincoln Electric Company

   1. W. Sindel, 1st Vice Chair Alstom Power, Incorporated

T. L. Niemann, 2nd Vice Chair Minnesota Department of Transportation

S. Morales, Secretary American Welding Society

N. J. Altebrando STV, Incorporated

F. G. Armao The Lincoln Electric Company

E. L. Bickford Acute Technological Services

*F. C. Breismeister Strocal, Incorporated

B. M. Butler Walt Disney World Company

H. H. Campbell III Loadmaster Universal Rigs

L. E. Collins Team Industries, Incorporated

R. B. Corbit Exelon Nuclear Corporation

R. A. Dennis Consultant

M. A. Grieco Massachusetts Highway Department

C. R. Hess High Steel Structures, Incorporated (Retired)

1. W. Holmes Modjeski and Masters, Incorporated

   J. J. Kenney Shell International E & P

   J. H. Kiefer ConocoPhillips Company

   V. Kuruvilla Genesis Quality Systems, Incorporated

   J. Lawmon American Engineering & Manufacturing, Incorporated

2. R. Lawrence II Butler Manufacturing Company

N. S. Lindell Inspectech, Incorporated

D. R. Luciani Canadian Welding Bureau

S. L. Luckowski Department of the Army

P. W. Marshall MHP Systems Engineering

M. J. Mayes Mayes Testing Engineers, Incorporated

D. L. McQuaid D. L. McQuaid and Associates, Incorporated

R. D. Medlock High Steel Structures, Incorporated

J. Merrill MACTEC, Incorporated

J. B. Pearson, Jr. LTK Engineering Services

D. C. Phillips Hobart Brothers Company

J. W. Post J. W. Post and Associates, Incorporated

D. D. Rager Rager Consulting, Incorporated

T. J. Schlafly American Institute of Steel Construction

D. R. Scott PSI (Retired)

*D. A. Shapira URS—Washington Division

R. E. Shaw, Jr. Steel Structures Technology Center, Incorporated

R. W. Stieve Greenman-Pedersen, Incorporated

P. J. Sullivan Massachusetts Highway Department (Retired)

M. M. Tayarani Massachusetts Highway Department

K. K. Verma Federal Highway Administration

B. D. Wright Advantage Aviation Technologies

*Deceased

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Advisors to the AWS D1 Committee on Structural Welding

W. G. Alexander WGAPE

E. M. Beck MACTEC, Incorporated

O. W. Blodgett The Lincoln Electric Company

M. V. Davis Consultant

G. L. Fox Consultant

G. J. Hill G. J. Hill and Associates, Incorporated

1. L. Hoitomt Hoitomt Consulting Services

   W. A. Milek, Jr. Consultant

   J. E. Myers Consultant

   
   

   AWS D1F Subcommittee on Strengthening and Repair

2. J. Altebrando, Chair STV, Incorporated

S. W. Kopp, Vice Chair High Steel Structures, Incorporated

S. Morales, Secretary American Welding Society

C. W. Holmes Modjeski & Masters, Incorporated

P. Rimmer New York State Department of Transportation

J. D. Ross U.S. Army Corps of Engineers

R. W. Stieve Greenman-Pedersen, Incorporated

M. M. Tayarani Massachusetts Highway Department

Advisors to the AWS D1F Subcommittee on Strengthening and Repair

E. M. Beck MACTEC Engineering & Consulting

C. R. Hess High Steel Structures

G. J. Hill G. J. Hill & Associates

M. J. Mayes Mayes Testing Engineers, Incorporated

J. W. Post J. W. Post & Associates, Incorporated

R. E. Shaw, Jr. Steel Structures Technology Center, Incorporated

W. A. Thornton Cives Corporation

R. H. R. Tide Wiss, Janney, Elstner Associates

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Foreword

This foreword is not part of AWS D1.7/D1.7M:2010, Guide for Strengthening and Repairing Existing Structures, but is included for informational purposes only.

This guide has been developed to assist in the task of strengthening and repairing existing structures. The guide includes information to assist both Engineers and Contractors in order to provide general direction and guidance on weld repairs, weld strengthening, and other procedures to correct challenging issues faced while dealing with existing structures.

Informative Annexes. These annexes are not part of this guide but are provided to clarify the guide’s recommendations by showing examples, providing information, or suggesting alternative good practices.

Errata. It is the Structural Welding Committee’s Policy that all errata should be made available to users of the code. Therefore, any significant errata will be published in the Society News Section of the Welding Journal and posted on the AWS web site at: https://www.aws.org/technical/d1/.

Suggestions. Your comments for improving AWS D1.7/D1.7M:2010, Guide for Strengthening and Repairing Existing Structures are welcome. Submit comments to the Managing Director, Technical Services Division, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126; telephone (305) 443-9353; fax (305) 443-5951; e-mail info@aws.org; or via the AWS web site <https://www.aws.org>.

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Table of Contents

Page No.

Personnel v

Foreword vii

List of Tables x

1. General Provisions 1

   1. Scope. 1

   2. Limitations 1

   3. Approval 2

   4. Safety Precautions 2

   5. Standard Units of Measure 2

2. Normative References 2

3. Terms and Definitions 2

4. Weldability 3

   1. Scope. 3

   2. Introduction. 3

   3. Structural Metals 4

   4. Weldability Based on Steel Composition 6

   5. Welding Procedures and Techniques 11

   6. Weldability Testing 12

5. Evaluation of Existing Welds 14

   1. Scope. 14

   2. Strength Evaluation 15

6. Testing and Sampling 24

   1. General Considerations 24

   2. Sampling and Testing Plan 24

   3. NDT Methods for Flaw Detection 25

   4. NDT Methods for Material Identification 27

   5. NDT Methods for Flaw Sizing and Characterization 27

   6. NDT Methods to Determine Existing Stress Levels 27

   7. NDT Methods to Determine Corrosion Effects 27

   8. NDT Personnel Certification 28

7. Heat Straightening 29

   1. Evaluating Damaged Structural Steel 29

   2. Restraining Forces 29

   3. Heat Application 29

8. Strengthening and Damage Repair 31

   1. Scope. 31

   2. Possible Causes of Damage 31

   3. Written Repair Procedures 32

   4. Methods of Repair 33

   5. General Repair Considerations 33

Annex A (Informative)—Informative References 35

Annex B (Informative)—Guidelines for the Preparation of Technical Inquiries for the Structural

Welding Committee 39

List of AWS Documents on Structural Welding 41

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List of Tables

Table Page No.

1. Fillet Weld Sizes 23

2. AWS D1.1, Figure 5.4 Convexity Limitations 23

1. Temperature Limits for Heat Application 30

2. Torch Tip Guide 30

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Guide for Strengthening and Repairing Existing Structures

1. General Provisions

   1. Scope. This document contains basic information pertinent to the welded strengthening and repair of existing steel structures. The information contained in this guide is intended for both Engineers and Contractors with the purpose of providing direction and guidance to perform weld repairs, weld strengthening, and other weld procedures to correct problematic issues with existing structures. This guide contains background information that will be useful to the Engineer who is obligated under AWS D1.1/D1.1M:2008 Clause 8 to provide a comprehensive plan to address projects that involve strengthening and repairing of steel structures. The approach to the strengthening and repairing of these materi- als is to be developed using the information provided herein.

      This guide is intended to apply to the strengthening and repair of existing structures made of the following materials:

      1. Steel with a minimum specified yield strength of 100 ksi [690 MPa] or less

      2. Cast iron

      3. Wrought iron

         Strengthening or repairing an existing structure includes modifications to meet new serviceability or load requirements as well as corrections made to repair conditions unsuitable for future use specified by the Engineer. The Engineer should prepare a contract for the work including, but not limited to, design, workmanship, inspection, acceptance criteria, and documentation. Except as modified in this clause, provisions of this guide should apply to the strengthening and repair of existing structures, including heat straightening of distorted members.

   2. Limitations. This guide is intended to assist in the evaluation of existing structural elements and the development of appropriate procedures for repairing those elements. It does not provide exhaustive coverage of any specific topic.

      This guide is intended to apply to the strengthening and repair of existing buildings and other structural systems. It is not intended to apply to:

      1. Structures made of steels less than 1/8 in [3 mm] thick

      2. Pressure vessels and pressure piping

      3. Structures made of materials other than those listed under the scope

      4. Seismic upgrades

      5. New construction

Whereas this guide is not intended to apply the application outside the scope, the principles contained in this guide may be applied to other materials and applications. The Engineer is advised to use caution and engineering judgment for appli- cation outside the scope of this guide.

More importantly, it is critical to state here that this document does not provide detailed specific procedures and direc- tion to correct any specific strengthening or repair operation regardless of how common or standard the procedure may be. Instead, information supplied herein as well as that material referenced in Annex A is intended to provide users with an overall approach to weld modifications as they pertain to: strengthening and repair; technical resources to develop

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