7709.56b,T of C Page 1 of 12 FSH 7709.56b - TRANSPORTATION STRUCTURES HANDBOOK Contents ZERO CODE CHAPTER 1 PLANNING 2 STRUCTURE LOCATION 3 SITE SURVEYS 4 PRELIMINARY DESIGN 5 HYDROLOGY 6 HYDRAULICS 7 STRUCTURAL DESIGN 8 OPERATION 9 CONSTRUCTION ZERO CODE Contents 01 AUTHORITY 02 OBJECTIVE 03 POLICY 04 RESPONSIBILITY 05 DEFINITIONS 08 REFERENCES CHAPTER 1 - PLANNING Contents 1.01 Authority 1.02 Objective 1.03 Policy 1.04 Responsibility 1.1 PRELIMINARY PLANNING 1.11 Road Management Objective 1.12 Alternatives 1.13 Costs 1.14 Project Development Process (Flow Chart) 1.2 PROJECT FUNDING 1.3 REQUIRED DESIGN INFORMATION 1.4 PROJECT ENGINEERING REPORT 1.41 Report Contents 1.42 Report Preparation, Review, and Approval CHAPTER 2 - STRUCTURE LOCATION Contents 2.02 Objective 2.03 Policy 2.04 Responsibility 2.1 RECONNAISSANCE 2.2 SITE SELECTION 2.3 FITTING THE STRUCTURE TO THE SITE CHAPTER 3 - SITE SURVEYS Contents 3.02 Objective 3.03 Policy 3.04 Responsibility 3.1 FOUNDATION INVESTIGATION 3.11 Field Reconnaissance 3.12 Preliminary Investigation 3.13 Foundation Investigation Report 3.14 Final Investigation 3.2 GUIDELINES FOR PREPARING TOPOGRAPHIC MAPS 3.21 Use of Photogrammetry 3.3 ROAD DESIGN INFORMATION 3.4 STREAM CHANNEL SURVEY 3.5 ADDITIONAL DATA 3.51 Information on Existing Substructure 3.52 Information on Nearby Structures 3.53 Photographs CHAPTER 4 - PRELIMINARY DESIGN Contents 4.02 Objectives 4.03 Policy 4.04 Responsibility 4.05 Definition 4.08 References 4.1 PRELIMINARY DESIGN PROCESS 4.2 SELECTING ALTERNATIVE STRUCTURE TYPES 4.3 DESIGN CONSIDERATIONS 4.31 Appearance 4.32 Waterways 4.33 Long-Term Versus Short-Term Structures 4.34 Modular Portable Bridges 4.35 Use of Previously Used Materials 4.35a General Requirements 4.35b Railroad Car Units 4.4 ECONOMIC ANALYSIS OF ALTERNATIVES 4.5 SELECTING THE ALTERNATIVE FOR FINAL DESIGN 4.51 Documentation CHAPTER 5 - HYDROLOGY Contents 5.02 Objective 5.03 Policy 5.04 Responsibility 5.05 Definitions 5.08 References 5.1 GENERAL PROCEDURES 5.2 PROBABILITY AND FREQUENCY 5.3 TYPES OF FLOW DATA 5.4 ESTIMATING PEAK FLOW 5.41 Gauge Data 5.42 United States Geological Survey Regression Equations 5.43 Federal Highway Administration Regression Equations 5.44 Rational Formula 5.45 Soil Conservation Service Methods 5.45a Watersheds Smaller Than 2,000 Acres 5.45b Watersheds Up to 20 Square Miles 5.46 Locally Developed Data 5.47 Historical Methods 5.5 METHODS FOR DEVELOPING HYDROGRAPHS 5.51 Unit Hydrographs From Gauge Data 5.52 Synthetic Unit Hydrographs 5.52a Snyder and Soil Conservation Service Synthetic Unit Hydrographs 5.52b United States Geological Survey Synthetic Unit Hydrographs CHAPTER 6 - HYDRAULICS Contents 6.02 Objective 6.03 Policy 6.04 Responsibility 6.05 Definitions 6.08 References 6.08a Open-Channel Flow 6.08b Bridge Hydraulics 6.08c Fords, Vented Fords, and Low-water Bridges 6.08d Culvert Hydraulics 6.08e Energy Dissipators 6.1 HYDRAULIC DESIGN OF CHANNELS 6.11 Open-Channel Hydraulics 6.11a Flow States 6.11b Open-Channel Flow Equations 6.11c Stage Discharge Curves 6.12 Roadside Channels 6.13 Channel Modification 6.14 Channel Stabilization 6.14a Spurs and Retarding Structures 6.14b Grade Control Structures 6.14c Channel Linings 6.15 Fish Passage 6.2 HYDRAULIC DESIGN OF BRIDGES 6.21 Bridge Location 6.22 Bridge Hydraulic Analysis 6.23 Scour 6.24 Pier Design 6.25 Abutment Design 6.26 Bridge Hydraulic Capacity 6.27 Relief Structures 6.3 FORDS, VENTED FORDS, AND LOW-WATER BRIDGES 6.31 Selection Considerations 6.31a Paved or Natural Fords 6.31b Vented Fords 6.31c Low-Water Bridges 6.32 Design Considerations 6.32a Natural Fords 6.32b Paved Fords 6.32c Vented Fords 6.32d Low-Water Bridges 6.33 Hydraulics of Fords, Vented Fords, and Low-Water Bridges 6.33a Fords 6.33b Vented Fords 6.33c Low-Water Bridges 6.4 HYDRAULIC DESIGN OF CULVERTS 6.41 Location and Installation 6.42 Site Surveys 6.43 Culvert Type 6.43a Shape 6.43b Materials 6.43c Number of Barrels 6.44 End Treatments 6.45 Culvert Hydraulics 6.45a Headwater Depth 6.45b Tailwater Depth 6.45c Conditions of Flow 6.45d Entrance Configuration 6.45e Culvert Flow Depth and Outlet Velocity 6.45f Overtopping Flow 6.45g Calculation of Overtopping Flow 6.46 Fish Passage 6.46a Design Requirements for Fish Passage 6.46b Types of Culverts for Fish Passage 6.47 Debris Control 6.5 MISCELLANEOUS CULVERT DESIGN CONSIDERATIONS 6.51 Energy Dissipators 6.51a Types of Energy Dissipators 6.51b Flow Conditions 6.52 Scour CHAPTER 7 - STRUCTURAL DESIGN Contents 7.01 Authority 7.02 Objective 7.03 Policy 7.04 Responsibility 7.08 References 7.1 GENERAL STANDARDS 7.11 Use of Regional Standard Designs/Drawings 7.12 Culverts 7.13 Previously Used Materials 7.2 DESIGN SPECIFICATIONS 7.21 Bridge Widths 7.22 Design Loads 7.23 AASHTO Fatigue Design Stress 7.24 Bridge Railings 7.25 Approach Railing 7.3 DESIGN CALCULATIONS AND DRAWINGS 7.4 STRUCTURE LIFE 7.5 FORDS AND LOW-WATER CROSSINGS 7.6 TRAIL BRIDGES 7.7 CHANNEL MODIFICATIONS 7.8 CONSTRUCTION ACCESS (TEMPORARY) BRIDGES 7.9 SUBSURFACE DRAINAGE SYSTEMS 7.91 Types of Subsurface Drains CHAPTER 8 - OPERATION Contents 8.01 Authority 8.02 Objectives 8.03 Policy 8.04 Responsibility 8.05 Definition 8.08 References 8.1 TECHNICAL INSPECTIONS 8.11 Bridges Under Other Jurisdictions 8.12 Inspection Intervals 8.13 Qualifications of Personnel 8.14 Technical Inspection Procedures 8.14a Field Work 8.14b Condition Inspection 8.14c Appraisal Evaluation 8.15 Inspection Report 8.16 Inventory Updates 8.17 Reporting 8.17a Bridges Under Other Jurisdictions 8.17b Forest Service Bridges Subject to the National Bridge Inspection Standards 8.2 PERMANENT BRIDGE RECORDS 8.3 DETERMINING BRIDGE CAPACITY 8.31 General Requirements 8.32 Load Ratings 8.33 Posting 8.34 Weight Limits and Signing 8.35 Object Markers 8.4 INVENTORIES 8.5 SUBSTANDARD RAILINGS ON EXISTING BRIDGES CHAPTER 9 - CONSTRUCTION Contents 9.02 Objectives 9.03 Policy 9.04 Responsibility 9.08 References 9.1 GENERAL REQUIREMENTS 9.2 CONSTRUCTION ENGINEERING REQUIREMENTS 9.21 Construction Inspection Plan 9.22 Construction Inspection Certification 9.23 Contractor Drawings 9.24 Final Construction Report 9.25 As-Built Drawings