Composite Arch “Bridge-in-a-Backpack” System
description
Transcript of Composite Arch “Bridge-in-a-Backpack” System
Outline1. What & How? 2. Design options3. Overview of recent projects4. Specific project details5. Performance tested in Lab6. AIT’s services “ How can we work
with you? ”
Composite Arch “Bridge-in-a-Backpack” System
What is the “ Bridge-in-a-Backpack ” System
Image Credit – NY Times/University of Maine
“ A Hybrid bridge system combining benefits of high-performance composites with durability and cost savings of cast-in-place concrete”
Carbon Fiber Composite + Concrete Arch Superstructure
Projects Completed & UnderwayStatus Bridge Location/Name
DescriptionConst.Year Key Stats
Complete(7)
Pittsfield, ME – Neal BridgePilot Project with University of Maine
2008 29.0’ Span23 Arches
Anson, ME – McGee BridgeMunicipal Design/Build Project
2009 28.0’ Span9 Arches
Bradley, ME – Jenkins BridgeMaine Composite Bridge Initiative
2010 28.5’ Span14 Arches
Auburn, ME – Jenkins BridgeMaine Composite Bridge Initiative
2010 38.0’ Span13 Arches
Belfast, ME – Perkins BridgeMaine Composite Bridge Initiative
2010 48.0’ Span16 Arches
Hermon, ME – Tom Frost Memorial BridgeSnowmobile/Pedestrian Bridge
2010 44.5’ Span3 Arches
Fitchburg, MAMA DOT Accelerated Bridge Program
2011 37.5’ Span15 Arches
Under Construction
(2)
Caribou, ME – Farm Access OverpassMaine Composite Bridge Initiative
2011 54.0’ Span22 Arches
Pinkham’s Grant, NHState Bridge Program
2011 24.5’ Span6 Arches
Design &Proposal
Bridges in design in ME, MI, proposals submitted in 11 states
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Design Options - Headwalls
• FRP Panel Walls– MSE or Through-Tied Configurations– Compatible with skewed bridges– Lightweight, easy to install– Durable, and cost competitive
• Concrete – Precast or CIP– MSE, Through-Tied, or Gravity– PC Panel, PCMG Units, Cast-in-place– Versatile design options– More conventional aesthetic
Multiple options to meet the Engineering, Economic, and Aesthetic requirements of the site
Headwall Options for Test-Level 4 Design
• Wall-mounted Barriers– Precast or CIP Gravity Wall– Precast Panel MSE Walls
McGee Bridge Replacement Example – 28’ Span
CONSTRUCTION SEQUENCE
1. Demo. existing steel bridge2. Excavate for footings3. Drill bedrock, form footings4. Arch installation5. Pour concrete footings6. Install composite decking7. Fill arches with concrete8. Erect composite headwalls9. Pour deck concrete10. Backfill bridge, install geogrid11. Finish grading12. Guardrails and cleanup
12 Days Total Construction TimeLow Bid Against Steel, Concrete, Wood
A note on footings
Perkins Bridge, Belfast, MERoyal River Bridge, Auburn, ME
Steel H-piles Spread Footings
Key Metrics• Span – 54’-2”• Rise – 12’-0½”• Rise/Span – 22%• Skew – 30 deg
• 22 – 15” Diameter Arches• Arch weight ~300lb each• Precast Concrete MSE
Headwalls/Wingwalls
Caribou Connector Bridge
Caribou Connector Bridge
Caribou Connector Bridge
How we got here- “Bridges to the future, now”
FHWA’s Public Interest Finding:• Allows for federal funding on projects where aspects deviate from typical
requirements, when in the interest of the public. i.e. in cases of “Cost-Effectiveness or System Integrity…” [FHWA]
• Simple application process – approval from FHWA in as little as 2 days
Maine’s Composites Initiative
• Six bridges in two years
• Variety of bridges to best gage how system fit’s into Maine’s bridge inventory
• 28-55’ spans• Stream/road crossing• Foundation types• Headwall designs
[FHWA Contract Administration Core Curriculum Manual, Section 3.C, http://www.fhwa.dot.gov/construction/cqit/findings.cfm]
Also being used in:
• Massachusetts
• New Hampshire
• Michigan
• Proposals in 11 states & 3 countries outside the US
Design-Build - Detail-Build - Value Engineering
Load-Deflection Response of Concrete-Filled FRP Tubular Arch
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Vertical Deflection at Crown (in)
App
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Initial Static Test to Failure Post-Failure Behavior
Performance Testing: Arch Testing
HL-93 Design Load Equivalent
National Recognition for Bridge-in-a-Backpack
Engineering Excellence Award Royal River Bridge, Auburn, ME
(Along with Maine DOT & Kleinfelder |SEA)
AASHTO TIG - 2011 Focus Technology
Product featured in: Engineering News Record,
The NY Times,Concrete International,
Popular Science, Popular Mechanics, The Boston Globe
American Society of Civil Engineers2011 Charles Pankow Award for
Innovation
2010 Award for Composites ExcellenceMost Creative Application
Summary and Quick Facts on CFFT Arch BridgesInnovative Product Application
• Rapid fabrication our facility or option to fabricate at/near jobsite
• Hybrid composite-concrete system improves material performance
• Steel free superstructure
• Reduced carbon footprint
Performance Tested• Design/tested to exceed AASHTO load
requirements
• Superior redundancy – safe system
• Corrosion resistant materials
• Field load testing indicates even greater levels of safety
Cost Effective and Fast Installation• Light weight product– reduces equipment
transportation needs
• Erected with a small crew, no skilled labor
• Performs up to 2x lifespan of conventional materials
• Accelerated Bridge Construction
• Rapid design, fabrication, and delivery
What can AIT do for you?
• Structural Design– AIT’s engineers design the composite arch bridge superstructure– AIT can design the bridge substructure, internally or with consultants– Optimization to maximize efficiency of structure
• Supply– AIT supplies a complete engineered bridge system– Packages: arches/decking, modular FRP headwalls– Installation Oversight
Daniel BannonStructural Engineer
Jonathan KenersonManufacturing Manager