Underwater Bridge Repair, Rehabilitation, and Countermeasures Publication No. FHWA-NHI-10-029 Pre-Publication Edition NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. The contents of this report reflect the views of the contractor who is responsible for the accuracy of the data presented herein. The contents do not necessarily reflect the official policy of the Department of Transportation. This report does not constitute a standard, specification, or regulation. The United States Government does not endorse products or manufacturers. Trade or manufacturers’ names appear herein only because they are considered essential to the object of this document. The conduct of underwater bridge inspections and repairs may frequently require the use of divers. While this manual contains information on diving equipment, it is neither intended to train personnel in diving nor enumerate all diving safety concerns and regulations. Actual diving operations can be extremely hazardous and should be undertaken only by personnel adequately trained to cope with the conditions that may be encountered. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. FHWA-NHI-10-029 4. Title and Subtitle 4. Report Date April 2010 Underwater Bridge Repair, Rehabilitation, and Countermeasures 6. Performing Organization Code: 7. Author(s) 8. Performing Organization Report No. Terence M. Browne, P.E.; Thomas J. Collins, S.E., P.E.; Michael J. Garlich, S.E., P.E.; John E. O’Leary, S.E., P.E.; Katherine C. Heringhaus 9. Performing Organization on Name and Address 10. Work Unit No. (TRAIS) Collins Engineers, Inc. 11. Contract or Grant No. 123 North Wacker Drive, Suite 300 Chicago, Illinois 60606 DTFH61-09-T-70027 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Final Report, January 2010 Office of Bridge Technology 14. Sponsoring Agency Code Federal Highway Administration 1200 New Jersey Avenue, S.E. HIBT-1 Washington, D.C. 20590 15. Supplementary Notes Contracting Officer’s Technical Representative (COTR): Louisa Ward FHWA Technical Consultant: Gary Moss 16. Abstract: Repairs to underwater bridge elements have been successfully completed for many years. However, the increased age of the nation’s bridges and related structures, as well as the increased emphasis in regular underwater inspection since the revisions to the National Bridge Inspection Standards in 1988 indicates an increased need to perform repairs to elements located below or in water. This manual is intended to serve as a reference for design engineers, construction inspectors, resident engineers, inspection divers and other administrative and technical staff whose work tasks include the repair or rehabilitation of elements of bridges or similar structures located below water. The manual addresses a variety of design and construction issues that must be considered in determining the feasibility of, and selecting the repair or rehabilitation methodology, for underwater projects. This information can aid in developing cost effective and durable repair and rehabilitation designs. 17. Key Words 18. Distribution Statement Bridge repair, underwater bridge repair, scour, No restrictions. This document is available from the bridge rehabilitation, scour countermeasures National Technical Information Services, Springfield, Virginia 22161 19. Security Classif. (of this report) 20. Security Classification (of this page) 21. No of Pages 22. Price Unclassified Unclassified Form DOT F 1700.7 (8-72) Reproduction of completed page authorized Underwater Bridge Repair, Rehabilitation, and Countermeasures Report No. FHWA-NHI-10-029 Prepared by Collins Engineers, Inc. 123 North Wacker Drive, Suite 300 Chicago, Illinois 60606 Prepared for Federal Highway Administration U.S. Department of Transportation Washington, D.C. 20590 May 2010 Underwater Bridge Repair, Rehabilitation, and Countermeasures—NHI Course 130091A Reference Manual TABLE OF CONTENTS CHAPTER I UNDERWATER REPAIR AND REHABILITATION OF BRIDGES AND STRUCTURES ................................................ 1-1 SECTION 1. INTRODUCTION ................................................................ 1-1 1-1.1 Purpose ............................................................... 1-1 1-1.2 Background ........................................................... 1-1 1-1.3 Scope .................................................................. 1-1 CHAPTER II MAINTENANCE ................................................................ 2-1 SECTION 1. INTRODUCTION ................................................................ 2-1 2-1.1 Marine Environment Factors ....................................... 2-1 2-1.2 Deterioration Models ................................................ 2-3 2-1.3 Preventive Maintenance Activities ................................ 2-5 2-1.4 Performance Monitoring ............................................ 2-6 CHAPTER III UNDERWATER REPAIR PLANNING DATA AND REPAIR OPTION ANALYSIS ............................................................ 3-1 SECTION 1. INTRODUCTION ................................................................ 3-1 SECTION 2. CONDITION ASSESSMENT ..................................................... 3-1 3-2.1 General ............................................................... 3-1 3-2.2 Steel ................................................................... 3-1 3-2.3 Timber ................................................................ 3-2 3-2.4 Masonry ............................................................... 3-2 3-2.5 Scour .................................................................. 3-3 3-2.6 Concrete .............................................................. 3-3 SECTION 3. STRUCTURAL ANALYSIS ...................................................... 3-6 3-3.1 Introduction .......................................................... 3-6 3-3.2 Piles ................................................................... 3-6 3-3.3 Undermining .......................................................... 3-7 3-3.4 Concrete .............................................................. 3-7 SECTION 4. REPAIR STRATEGY ............................................................ 3-8 CHAPTER IV MARINE CONSTRUCTION MATERIALS ..................................... 4-1 SECTION 1. INTRODUCTION ................................................................ 4-1 SECTION 2. STEEL ........................................................................... 4-1 i Underwater Bridge Repair, Rehabilitation, and Countermeasures—NHI Course 130091A Reference Manual 4-2.1 General ............................................................... 4-1 SECTION 3. CONCRETE ..................................................................... 4-3 4-3.1 Mix Design ............................................................ 4-3 4-3.2 Reinforcing ........................................................... 4-5 SECTION 4. MASONRY ....................................................................... 4-6 4-4.1 Stone .................................................................. 4-6 4-4.2 Mortar ................................................................. 4-6 SECTION 5. TIMBER ......................................................................... 4-6 4-5.1 Preservatives ......................................................... 4-7 4-5.2 Decay Reinforced Species .......................................... 4-7 4-5.3 Fabrication ........................................................... 4-7 SECTION 6. COMPOSITES ................................................................... 4-8 4-6.1 Components .......................................................... 4-8 4-6.2 Physical Properties .................................................. 4-8 4-6.3 Mechanical Properties .............................................. 4-8 4-6.4 Example Products ................................................... 4-9 CHAPTER V UNDERWATER REPAIRS ..................................................... 5-1 SECTION 1. INTRODUCTION ................................................................ 5-1 SECTION 2. GENERAL CONSTRUCTION OPTIONS ........................................ 5-1 5-2.1 Repairs Performed “In-the-Dry” ................................... 5-1 5-2.2 Repairs Performed “In-the-Wet” .................................. 5-1 SECTION 3. ENVIRONMENTAL CONSIDERATIONS ........................................ 5-2 5-3.1 Site Conditions ....................................................... 5-2 5-3.2 Water Conditions .................................................... 5-2 5-3.3 Regulatory ............................................................ 5-4 SECTION 4. METHODS TO OBTAIN DRY WORK CONDITIONS ........................... 5-5 5-4.1 Traditional Cofferdams ............................................. 5-5 5-4.2 Dikes ................................................................... 5-6 5-4.3 Proprietary Barrier Systems ........................................ 5-6 5-4.4 Limpet Cofferdams .................................................. 5-7 CHAPTER VI EQUIPMENT FOR UNDERWATER REPAIR ................................. 6-1 SECTION 1. INTRODUCTION ................................................................ 6-1 SECTION 2. DIVING SYSTEMS ............................................................... 6-1 6-2.1