1. New Hampshire Technical Transfer Josh Olund, P.E., PhD The Brookfield Floating Bridge New Hampshire Technical Transfer Josh Olund, P.E., PhD The Brookfield Floating Bridge April 7, 2016

2. Presentation Agenda Brief Project Background – Where, What & Why Design Criteria & Alternative Selection FRP Pontoon Design FRP Specification Development Approach Ramps Construction/Fabrication Questions Brief Project Background – Where, What & Why Design Criteria & Alternative Selection FRP Pontoon Design FRP Specification Development Approach Ramps Construction/Fabrication Questions

3. WHERE, WHAT AND WHY?

4. Project Location I-89 Project Site

5. Project Information Located on VT 65; Rural Minor Collector Added to the National Register of Historic Places Bridge closed in 2007 to vehicles and 2008 to pedestrians Bridge Committee formed Programmed for replacement in 2011 Located on VT 65; Rural Minor Collector Added to the National Register of Historic Places Bridge closed in 2007 to vehicles and 2008 to pedestrians Bridge Committee formed Programmed for replacement in 2011 Traffic Data: 20142034 AADT110120 DHV10 ADTT12 %T0.60.8

6. History of the Floating Bridge Originally constructed of floating logs in 1820 Bridge has been replaced 7 times Originally constructed of floating logs in 1820 Bridge has been replaced 7 times

7. Learning from the Past Log Bridge  Short Life, Low Capacity Floats under Logs  Floats Dislodge Secured Kerosene Barrels  Low Capacity, Short Life Secure Larger Oak Barrels  Better Capacity, Wet Feet Plastic Barrels + Raised Sidewalk  Barrels leaking Log Bridge  Short Life, Low Capacity Floats under Logs  Floats Dislodge Secured Kerosene Barrels  Low Capacity, Short Life Secure Larger Oak Barrels  Better Capacity, Wet Feet Plastic Barrels + Raised Sidewalk  Barrels leaking

8. Improvements for the Future More durable and maintenance free Modular to aid in major rehabilitation or replacement Improved and known capacity ADA compliant More durable and maintenance free Modular to aid in major rehabilitation or replacement Improved and known capacity ADA compliant

9. DESIGN CRITERIA AND ALTERNATIVE SELECTION

10. Owner Design Parameters 106 determination: New bridge must replicate appearance of existing structure Must be able to be maintained and replaced without removing the entire structure from the water Deck as close to the water without becoming submerged Sidewalk width and ADA requirements H12 Design Truck or 384 plf Lane loading plus 65 psf pedestrian loading 5 ft sidewalks, 12 ft lane 106 determination: New bridge must replicate appearance of existing structure Must be able to be maintained and replaced without removing the entire structure from the water Deck as close to the water without becoming submerged Sidewalk width and ADA requirements H12 Design Truck or 384 plf Lane loading plus 65 psf pedestrian loading 5 ft sidewalks, 12 ft lane

11. Owner Design Parameters (Cont.) Structure in-service from roadway overtopping down to 6” below normal water (3.4 ft elevation change) Need to consider ice pressure & snow loading 30 ft approach ramps, ADA compliant (8% max. grade) Service Criteria – Generally keep water out of travelway  avoid hydroplaning and “slime” Structure in-service from roadway overtopping down to 6” below normal water (3.4 ft elevation change) Need to consider ice pressure & snow loading 30 ft approach ramps, ADA compliant (8% max. grade) Service Criteria – Generally keep water out of travelway  avoid hydroplaning and “slime”

12. Concrete Flotation Alternative General Information: 10 ft deep, 39.5 ft long, 110 ton each (14 total) Cast on-site, likely within west approach Hollow sections to allow for inspection access General Information: 10 ft deep, 39.5 ft long, 110 ton each (14 total) Cast on-site, likely within west approach Hollow sections to allow for inspection access Construction Considerations: Permanent dredging and stone fill revetment Large crane or two cranes needed – minimal staging areas available

13. FRP Flotation Alternative Shallow sections - No lake dredging; fabricated offsite and delivered in short window Lightweight - Lighter equipment for installation Foam Filled - Offers redundancy; prevents water infiltration Shallow sections - No lake dredging; fabricated offsite and delivered in short window Lightweight - Lighter equipment for installation Foam Filled - Offers redundancy; prevents water infiltration

14. Proposed Structure

15. FRP PONTOON DESIGN INITIAL CONSIDERATIONS

16. Connections Hinged connection considered; resulted in large deflections Field splices used to create ‘monolithic’ float across lake Designed field splices with load factors approximately 2x higher than the remainder of the bridge Max anticipated deflection from waves <2”, so wave-induced fatigue was not considered Hinged connection considered; resulted in large deflections Field splices used to create ‘monolithic’ float across lake Designed field splices with load factors approximately 2x higher than the remainder of the bridge Max anticipated deflection from waves <2”, so wave-induced fatigue was not considered

17. Connections (Continued) Desire to avoid penetrations within the float Mechanical connections laterally for modular assembly and potential future repair/removal Desire to avoid penetrations within the float Mechanical connections laterally for modular assembly and potential future repair/removal

18. FRP PONTOON DESIGN DESIGNING WITH FRP

19. FRP Design Challenges Minimal (near non-existent) design standards Lack of performance records in bridge applications Unknown/questionable material properties (at design phase) Minimal (near non-existent) design standards Lack of performance records in bridge applications Unknown/questionable material properties (at design phase)

20. FRP Design - Code Used: Pre-Standard for Load & Resistance Factor Design (LRFD) of Pultruded Fiber Reinforced Polymer (FRP) Structures (Final) Cross between timber and steel codes Required some extrapolation for bridge structures Used: Pre-Standard for Load & Resistance Factor Design (LRFD) of Pultruded Fiber Reinforced Polymer (FRP) Structures (Final) Cross between timber and steel codes Required some extrapolation for bridge structures

21. FRP Design – Factors Multiple condition factors, vary by stiffness, strength, resin type moisture temperature chemical Load Factors from AASHTO & Reduction Factors from ASCE Multiple condition factors, vary by stiffness, strength, resin type moisture temperature chemical Load Factors from AASHTO & Reduction Factors from ASCE load sharing load sharing composite action composite action duration duration

22. FRP Design – Material Properties Increased fiber volume = increased strength, decreased thermal movements Material properties change depending on load direction Stiffness not constant nor directly related to Strength E s = 29,000 ksi E c = 1820* (f`c) E frp = based on fiber volume, type, resin type Increased fiber volume = increased strength, decreased thermal movements Material properties change depending on load direction Stiffness not constant nor directly related to Strength E s = 29,000 ksi E c = 1820* (f`c) E frp = based on fiber volume, type, resin type

23. FRP PONTOON DESIGN MODELING ITERATIONS

24. FRP Design – Project Approach Partnered with UMaine to provide material property guidance Used naval architect to model a variety of sections and strengths Bounded section properties and strengths within the special provisions Partnered with UMaine to provide material property guidance Used naval architect to model a variety of sections and strengths Bounded section properties and strengths within the special provisions

25. 3D FRP Pontoon Model Shell elements on elastic foundation (FRP only) Investigate ice pressure, tire loads Develop plate thickness for 2D model Shell elements on elastic foundation (FRP only) Investigate ice pressure, tire loads Develop plate thickness for 2D model

26. 2D FRP Pontoon Model Beam model on elastic foundation Used unit loads to produce influence surfaces

27. 2D FRP Pontoon Model Post processed influence lines to determine appropriate load patterns and envelope design parameters

28. FRP SPECIFICATION DEVELOPMENT

29. FRP Specifications - Materials Resin – Epoxy-vinyl ester or marine grade epoxy based with 10% max additional styrene 0.3% UV 9 added for ultraviolet protection Fiber Reinforcement: Electrical grade (E-Glass) Minimum amounts identified by volume and orientation Resin – Epoxy-vinyl ester or marine grade epoxy based with 10% max additional styrene 0.3% UV 9 added for ultraviolet protection Fiber Reinforcement: Electrical grade (E-Glass) Minimum amounts identified by volume and orientation

30. FRP Specifications – Design Calc’s Provide design parameters, unique loading conditions, resistance factors, and environmental factors Provide enveloped physical constraints Provide design parameters, unique loading conditions, resistance factors, and environmental factors Provide enveloped physical constraints FRP Raft Physical Constraints Raft Weight (lb) Vertical Bending Stiffness, E*I x (kip*in 2 ) Plate Thickness (in) Vertical Neutral Axis Location, Measured from Bottom Fiber (in)

31. FRP Specifications – Proof Tests Fabricator required to prove design is feasible Table I – Prefabrication Proof Testing Requirements Physical/Mechanical propertyRequirements ASTM Test Method Barcol Hardness> 40D2583 Water Absorption< 0.7%D570 Density Within ± 5% of theoretical design value D792 Coefficient of Thermal Expansion (Longitudinal)< 8x10 -6 in/in/ o FD696 Coefficient of Friction for Adjoining Pontoon Surfaces > 0.45 (Wet Conditions) D1894 Fiber Volume Fraction> 45% by volumeD2584 Tensile Strength Longitudinal> 30 ksi D3039 Transverse> 15 ksi Tensile Modulus Longitudinal> 2,000 ksi D3039 Transverse> 1,500 ksi Compressive Strength Longitudinal> 30 ksi D6641 Transverse> 15 ksi Compressive Modulus Longitudinal> 1,800 ksi D6641 Transverse> 1,400 ksi Flexural Strength Longitudinal> 35 ksi D7264 Transverse> 20 ksi Flexural Modulus Longitudinal> 1,800 ksi D7264 Transverse> 1,400 ksi In-plane Shear Strength> 12 ksiD5379 In-plane Modulus> 600 ksiD5379 Interlaminar Shear Strength> 3.5 ksiD2344 Pin Bearing Strength 1 > 20 ksiD953

32. APPROACH RAMPS

33. Approach Ramps Not as simple as they seem… Need to accommodate: Vertical (gravity) loads Lateral wind loads Torsion due to unbalanced loading (think extreme support settlement) Not as simple as they seem… Need to accommodate: Vertical (gravity) loads Lateral wind loads Torsion due to unbalanced loading (think extreme support settlement)

34. Approach Ramps – Vertical Loads Non-composite glued-laminated girders Live load distribution through timber deck and diaphragms Material type used over historics Non-composite glued-laminated girders Live load distribution through timber deck and diaphragms Material type used over historics

35. Approach Ramps – Lateral Loads Tie-rods used beneath girders provide lateral stiffness to the overall system Bearings have overlapping C-shapes which essentially doesn’t allow localized rotation Frame and Truss Action Tie-rods used beneath girders provide lateral stiffness to the overall system Bearings have overlapping C-shapes which essentially doesn’t allow localized rotation Frame and Truss Action

36. Approach Ramps – Torsion Needs to be rotationally flexible – ends of girders to follow pontoon movement Released” girders by: Separating deck panels (no joint connectivity) Connecting diaphragms with single, centered rod No uplift capacity at bearings Needs to be rotationally flexible – ends of girders to follow pontoon movement Released” girders by: Separating deck panels (no joint connectivity) Connecting diaphragms with single, centered rod No uplift capacity at bearings End Pontoon 65 psf H12

37. Approach Ramps – Torsion

38. CONSTRUCTION/FABRICATION

39. Fabrication VARTM process used with single mold

40. Fabrication Pontoons preassembled at fabrication facility for accuracy

41. Construction Assembled on land, lifted in to Lake

42. Construction Pontoons field connection

43. Construction Approach ramp girders installed

44. Construction Timber construction through winter

45. Construction Completed Structure

46. QUESTIONS?