AWS D1.7:2010

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.
Scope : 1. General Provisions 1.1 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 materials 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. 1.2 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 application outside the scope of this guide. More importantly, it is critical to state here that this document does not provide detailed specific procedures and direction to correct any specific strengthening or repair operation regardless of how common or standard the procedure maybe. 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 appropriate detailed specific strengthening and repair contract documents or procedures; summarized guidance on typical weldability of common metals; summarized guidance for testing the serviceability of the procedures and a summary of common procedures and approaches that are intended to be modified for the specific procedure. 1.3 Approval. All references to â??approvalâ? should be interpreted to mean approval by the Engineer. 1.4 Safety Precautions. Safety and health issues and concerns are beyond the scope of this standard and therefore are not fully addressed herein. However, in addition to the material supplied in subsequent chapters of this document, pertinent information can be found in the following standalone documents: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes, and applicable federal, state, and local regulations. Other pertinent information can be found in the manufacturerâ??s safety literature on equipment and materials. These documents should be referred to and followed as required. NOTE: This guide may involve hazardous materials, operations, and equipment. The document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices. The user should determine the applicability of any regulatory limitations prior to use. 1.5 Standard Units of Measure. This guide makes use of both U.S. Customary Units and the International System of Units (SI). The latter are shown within brackets ([ ]) or in appropriate columns in tables and figures. The measurements may not be exact equivalents; therefore, each system should be used independently of the other.