English -- The Manual for Bridge Evaluation - 3rd Edition

Abstract

Scope: The Manual has been divided into eight Sections, with each Section representing a distinct phase of an overall bridge inspection and evaluation program. • Section 1—Purpose, scope, applicability, inspection and evaluation quality measures, and definition of general interest terms. • Section 2—Provisions for proper documentation to be included in a bridge file. The bridge file associated with each bridge provides the foundation against which changes in physical condition can be compared. • Section 3—Overview of bridge management systems and their key elements. • Section 4—Types and frequency of field inspections, as well as specific inspection techniques and procedures. • Section 5—Various inspection and evaluation testing methods. Conditions at a bridge site or the absence of information from original construction may warrant more elaborate material tests to determine properties for evaluation. • Section 6—Nationally recognized specification for the load rating of bridges. Includes the Load and Resistance Factor method, the Load Factor method, and the Allowable Stress method. • Section 7—Provisions for the evaluation of existing bridges for fatigue. • Section 8—Field-performed load test procedures. Field load testing is a means of supplementing analytical procedures in determining the live-load capacity of a bridge and for improving the confidence in the assumptions. The successful application of this Manual is directly related to the DOT organizational structure. Such a structure should be both effective and responsive so that the unique characteristics and special problems of individual bridges are considered in developing an appropriate inspection plan and load capacity determination. PURPOSE The purpose of The Manual for Bridge Evaluation (MBE) is to serve as a resource for use in developing specific policy and procedures for the inspection and evaluation of existing in-service highway bridges. The MBE also includes the nationally recognized guidance for the load rating of highway bridges. The National Bridge Inspection Standards (NBIS), as found in the Code of Federal Regulations (23 CFR 650 Subpart C), define the regulations for the inspection and evaluation of the nation’s bridges. The MBE is incorporated by reference in the CFR (23 CFR 650 Subpart C) to be used along with other reference documents such as the American Association of State Highway and Transportation Officials (AASHTO) Manual for Bridge Element Inspection, the Federal Highway Administration’s (FHWA) Bridge Inspector’s Reference Manual (BIRM), and the latest National Bridge Inventory (NBI) coding guidance document for the inspection and evaluation of the nation’s bridges. The NBIS have evolved and been improved over the years since their creation in the early 1970s. The MBE has also evolved and been revised and improved to reflect best practices as determined by research, state departments of transportation (DOTs), and others. In the future as improved practices and research are developed, the MBE will reflect those improvements. Throughout this Manual there are subsections titled in part “Provisions to Support the NBIS Requirements.” These subsections were developed to provide specific guidance and best practices that are considered to be required under the regulations. APPLICABILITY The provisions of this Manual apply to all highway structures that qualify as bridges in accordance with the AASHTO definition of a bridge (see Article 1.5). These provisions may be applied to smaller structures which do not qualify as bridges at the discretion of the DOT. The NBIS establish minimum requirements for inspection programs and minimum qualifications for bridge inspection personnel. The NBIS apply to all highway bridges that are more than 20 ft in length and located on public roads. Where conflicts or inconsistencies exist between this Manual and the federal requirements specified in the NBIS, the FHWA coding guidance, or BIRM, the federal requirements shall govern.