These Recommendations pertain to the design, testing, and installation of stay cables for cable stayed bridges using prestressing wires, strand, or bar as the main tension element. Recommendations are presented only for stay cables used in redundant cable-stayed bridges.
These Recommendations pertain to the design, testing, and installation of stay cables for cable stayed bridges using prestressing wires, strand, or bar as the main tension element. Recommendations are presented only for stay cables used in redundant cable-stayed bridges.
These Recommendations are intended to be used in conjunction with the appropriate provisions of the “LRFD Bridge Design Specifications,” from the American Association of State Highway and Transportation Officials (AASHTO LRFD).
This edition supersedes all previous editions. Standards and specifications shall refer to the latest edition unless a specific date is given.
Updated items include saddle testing provisions, fire resistance qualification testing and vibration control system requirements.
Table of Contents
1.0 SCOPE
1.1 Referenced standards and specifications
1.1.1 American Association of State Highway and Transportation Officials (AASHTO)
1.1.2 American Welding Society (AWS)
1.1.3 ASTM International
1.1.4 British Standards Institute
1.1.5 California Department of Transportation (CALTRANS)
1.1.6 European Committee for Standardization
1.1.7 Federal Highway Administration (FHWA)
1.1.8 French Association for Standardization
1.1.9 German Institute for Standardization
1.1.10 International Federation for Structural Concrete (fib)
1.1.11 Post-Tensioning Institute (PTI)
1.1.12 SSPC: Society for Protective Coatings
1.1.13 Swiss Society of Engineers and Architects
2.0 NOTATION, DEFINITIONS, AND ABBREVIATIONS
2.1 Notation
2.2 Definitions
2.3 Abbreviations
3.0 MATERIALS
3.1 General
3.2 Main tension elements
3.2.1 Wire
3.2.1.1 Quality control
3.2.2 Strand
3.2.2.1 Quality control
3.2.3 Epoxy-coated strand
3.2.3.1 Quality control
3.2.3.2 Surface preparation
3.2.3.3 Application of epoxy coating
3.2.3.4 Inspection of materials
3.2.3.5 Replacement of rejected epoxy strand
3.2.4 Bar
3.2.4.1 Quality control
3.2.5 Wire or strand not specifically itemized in ASTM A421/A421M or A416/A416M
3.2.6 Bars not specifically itemized in ASTM A722/A722M
3.3 Individually sheathed strands with corrosion-inhibiting coating
3.3.1 Surface preparation
3.3.2 Application of corrosion-inhibiting coating
3.3.2.1 Quality control
3.3.3 Application of sheathing
3.3.4 Inspection
3.3.5 Replacement of rejected sheathed strand
3.3.6 High-density polyethylene material for sheathed strand
3.3.7 Polypropylene material for sheathed strand
3.3.8 Corrosion-inhibiting coating material
3.3.9 Performance tests for individually sheathed polyethylene or polypropylene strand
3.4 Anchorage components
3.5 Stay pipe
3.5.1 Cross-sectional area
3.5.2 Steel pipe
3.5.2.1 Coating
3.5.3 High-density polyethylene pipe
3.5.3.1 Pipe specifications
3.5.3.2 Material specifications
3.5.3.3 Wall thickness
4.0 SYSTEMS QUALIFICATION AND TESTING
4.1 Corrosion protection
4.1.1 General
4.1.2 Barriers
4.1.2.1 Anchorage/free length interface
4.1.3 Materials
4.1.4 Qualification of barriers
4.1.4.1 Internal barriers
4.1.4.2 External barriers
4.1.5 Qualification of temporary corrosion protec¬tion system
4.1.6 Qualification of anchorage assembly
4.1.6.1 Leak test
4.1.6.2 Preparation
4.1.6.3 Testing
4.1.7 Acceptance criteria
4.1.7.1 Barriers
4.1.7.2 Anchorage assembly
4.1.8 Documentation
4.2 Acceptance testing of stay cables
4.2.1 Limitations of full-scale acceptance testing of stay cables—seismic loading
4.3 Acceptance and performance testing of isolated MTE cable saddles
4.3.1 Introduction
4.3.2 Testing protocol for saddles
4.3.3 Friction testing
4.3.3.1 Testing procedure
4.3.3.2 Interpretation
4.3.4 Fatigue, strength, and corrosion protection
4.3.4.1 Qualification of saddles
4.3.4.2 Saddle fatigue test
4.3.4.3 Additional testing
4.3.5 Acceptance of prior tests of cable saddles
4.4 Acceptance of prior tests of stay cables
4.5 Quality control of other stay cable components
4.6 Fire resistance qualification testing
4.6.1 Furnace and test temperatures
4.6.2 Test specimen and monitoring temperature of MTE
4.7 Summary of testing requirements
5.0 LRFD DESIGN
5.1 Loads
5.1.1 Dead loads
5.1.2 Live loads
5.1.3 Fatigue load
5.1.4 Dynamic load allowance
5.1.5 Wind loads on stay cables
5.1.6 Thermal loads
5.2 Wind-induced vibrations
5.2.1 Mechanisms of dynamic excitation
5.2.2 Monitoring of cable vibrations
5.2.3 Design provisions
5.2.3.1 Contingency measures
5.2.3.2 Rain-wind-induced vibrations
5.2.3.4 Aerodynamic contour of cable
5.2.3.5 Damping
5.2.3.6 Stabilizing cables
5.2.3.7 Connections
5.2.3.8 Rattling
5.3 Design
5.3.1 Design limit states
5.3.2 Load factors and combinations
5.3.2.1 Construction limit state
5.3.3 Resistance factors
5.3.3.1 Special seismic resistance factors
5.3.4 Bending effects free length
5.3.4.1 Strength of stay cable anchorages for lateral loads
5.3.5 Fatigue limit state
5.4 Cable replacement
5.5 Loss of cable
5.5.1 Cable loss due to fire
5.6 Construction
5.7 Design of cable saddles
5.7.1 General
5.7.1.1 Design requirements
5.7.2 Design criteria
5.7.2.1 Cable radius
5.7.2.2 Slip and force transfer
5.7.2.3 Cable bending stresses
5.7.2.4 Cable loss with saddles
5.7.2.5 Analytical requirements for seismic loading
5.7.3 Detailing
5.7.3.1 Corrosion protection system
5.7.3.2 Qualification of saddle corrosion protection system details
5.7.4 Testing
5.7.4.1 Saddle design testing
5.7.4.2 — Fatigue testing
5.7.4.3 — Friction testing
5.8 Alternative stay cable systems
5.9 Guide pipe minimum design forces
5.10 Extrados/low-fatigue stay systems
6.0 INSTALLATION OF STAY CABLES
6.1 Quality control program
6.2 Fabrication
6.2.1 General
6.2.2 Prefabrication
6.2.3 Site fabrication
6.3 Handling of stay cable components
6.3.1 Procedures
6.3.2 Cable protection and coiling
6.3.3 Equipment and lifting devices
6.3.4 Damage and repair
6.4 Packing and shipping
6.4.1 Stay cable metallic components
6.4.2 Strands, wires, and bars
6.4.2.1 Bare strands and wires
6.4.2.2 Bare bars
6.4.2.3 Epoxy-coated, galvanized, or sheathed strand
6.4.3 Anchor and socket assemblies
6.4.4 Pipe
6.4.4.1 High-density polyethylene pipe without tension element
6.4.4.2 Steel pipe
6.4.5 Preassembled cables with HDPE pipe
6.5 Material site inspection
6.6 Storage
6.6.1 Requirements and limitations
6.6.2 Facility
6.6.3 Environmental control
6.7 Pre-installation inspection
6.7.1 Bare, epoxy-coated, galvanized, or sheathed strands and wire
6.7.2 Bare strands and wires
6.7.3 Epoxy-coated or sheathed strands
6.7.4 Bar
6.7.5 High-density polyethylene pipe
6.7.6 Steel pipe
6.7.7 Pre-assembled cable
6.7.8 Anchors and socket assemblies
6.8 Stay pipe assembly preparation
6.8.1 High-density polyethylene pipe
6.8.1.1 Pipe length
6.8.1.2 Fusion welds
6.8.2 Steel pipe
6.8.2.1 Welding requirements
6.8.2.2 Inspection for steel pipe welding
6.9 Installation
6.9.1 Installation program
6.9.1.1 Cable alignment and centering devices
6.9.1.2 Minimum cable forces
6.9.1.3 Final acceptance of stay forces
6.9.2 Vibration control
6.9.3 Jacks and gauges
6.9.4 Stressing
6.9.5 Detensioning
6.9.6 Installation records
6.9.6.1 Monitoring
6.9.6.2 Permanent records
7.0 STAY CABLE INSPECTION AND MONITORING
7.1 General
7.1.1 Design considerations
7.1.2 Inspection and maintenance
7.1.3 Inspections
7.2 Visual inspection of stays
7.3 Condition evaluation
7.4 Non-destructive evaluation and monitoring
7.5 Frequency of inspection
7.6 Monitoring of cable vibrations
7.7 Cable inspection and maintenance manual
7.7.1 Items for inspection and maintenance manual
8.0 VIBRATION CONTROL SYSTEM PERFORMANCE
8.1 Requirements
8.2 Working amplitudes
8.3 Extreme amplitudes
8.4 Operational conditions
8.5 Amplitude effect on anchors
8.6 Inherent structural damping
8.7 Performance verification
9.0 CITED REFERENCES
APPENDIX A DETAILS OF “ONE PIN TEST”
APPENDIX B SAMPLE OF GALVANIZED STRAND SPECIFICATIONS
APPENDIX C CORROSION PROTECTION SYSTEM DETAIL
App.C.1 Temporary corrosion protection
App.C.2 Wrapping with protective tape
App.C.3 Coating for steel pipe
App.C.3.1 Shop-applied prime coat
App.C.3.1.1 Surface preparation
App.C.3.1.2 Prime coat preparation
App.C.3.1.3 Prime coat application
App.C.3.1.4 Quality inspection for prime coat
App.C.3.2 Field-applied intermediate and finish coats
App.C.4 Portland cement grout
App.C.4.1 General
APPENDIX D CONVERSION FACTORS SI TO US UNITS
APPENDIX E ALTERNATE SADDLE FATIGUE TEST SETUP