Pre-Fabricated Steel Bridges for Accelerated Bridge Construction (ABC)
1. Steel: The Bridge Material of Choice
National Steel Bridge Alliance
A division of the American Institute of Steel Construction
www.steelbridges.org
PreFabricated
Steel Bridges
for
Accelerated
Bridge
Construction
Steel: The Bridge Material of Choice
National Steel Bridge Alliance
A division of the American Institute of Steel Construction
www.steelbridges.org
2. Current State of ABC Efforts In The US
• Over 800 bridges have
been designed or
constructed using
PreFabricated Bridge
Elements or Systems
(PBES) in last 3 years
• PreFabricated Bridge
Systems (complete
bridges) have historically
been steel bridges
• The use of steel
PreFabricated Bridge
Elements is growing fast
The following slides will feature
projects utilizing steel PreFabricated
Bridges or Modules
3. Coleman Bridge – VA
completed in 1995
PreFabricated Bridge System
4. Coleman Bridge – VA
completed in 1995
PreFabricated Bridge System
5. Coleman Bridge – VA
completed in 1995
PreFabricated Bridge System
8. 800 Structural elements
400 Gusset plates
13000 Bolts
11 weeks from contractors Notice to Proceed to
open for traffic
Eggners Ferry Bridge – KY
emergency span replacement
PreFabricated Bridge System
9. Sam White Bridge – UT
moved with Self Propelled Modular Transporters
Complete Steel Superstructures
10. Wellesley – MA
moved with Self Propelled Modular Transporters
Complete Steel Superstructures
11. Phillipston – MA
moved with Self Propelled Modular Transporters
Complete Steel Superstructures
22. Modular Steel Bridge System 1
Modular Pre-Framed Girders
• Conventional fabrication
• Tangent and skewed sections
• Options for decking
• Concrete cast off site / near site
• Precast concrete panels
• Timber
• Simple or continuous spans
23. Modular Steel Bridge System 2
Modular Shallow Bent Plate Box Girders
• Galvanized steel
• Concrete deck cast off site / near site
• Simple or continuous spans
• Very economical
24. Modular Steel Bridge System 3
Orthotropic Slab Bridge for Short Spans
• Long service life
• Low dead load vs. concrete deck
• Ideal for re-decking existing bridges
• Potential for automation of fabrication
25. Why Consider Modular Steel Elements?
Steel fabrication requirements are conventional
• Reducing risk
Steel’s light weight
• Permits re-use of existing substructure, foundation
• Minimizes shipping limitations
• Maximizes crane lift, reach & placement capabilities
Steel’s maximum span length / structure depth ratio
• Allows structure depth limitations
• Maintains existing approaches, or can increase underclearance
Steel construction can be faster
• Using bolted connections
Steel is prefabricated to a high degree of accuracy
• Accommodating complex geometries (skews, vertical curves)
• Ensuring proper field fit-up and final roadway alignment
26. Steel: The Bridge Material of Choice
National Steel Bridge Alliance
A division of the American Institute of Steel Construction
www.steelbridges.org
Steel: The Bridge Material of Choice
National Steel Bridge Alliance
A division of the American Institute of Steel Construction
www.steelbridges.org
Steel Bridges
for
Accelerated
Bridge
Construction
Notes de l'éditeur
Demand for ABC coming from customers, Once they’ve seen 1 ABC, they ask, ‘Why can’t they all be done this way?”And FHWA is doing whatever they can to help spread the gospel.Started with big projects, now finding it’s way into more typical bridges – highway overpasses, etc.So, I’ll be showing examples of successful ABC projects using steel as the principal structural component in the prefabricated bridge elements
A really big water crossingThis is some of the off-site fabrication that was done for the Coleman Bridge over the York River in Virginia.This fabrication was done in Norfolk, VA – 40 miles downriver from the bridge site
In this project, an outmoded 2 lane structure was completely replace with a new 4 lane structure The new structure is on the original alignment and used the original river caissons. Here 1 of the 2 swing spans is being lowered onto its pier.
This complete structure replacement – all 3750’ feet of it - required road closures totaling only 9 daysCompleted in 1995, it was the forerunner of big bridge moves.
A big water crossing – this 400’ span 3 rib arch arch had been built on the pier to the right in this photo This picture was taken just as it finished its move onto a barge to be towed to the final bridge site at the head of the Narragansett BayThis was PFBES with NO ABC
A new span swinging into place for the Eggners Ferry Bridge in the Kentucky lakes district – a major tourist area in KY.An errant cargo ship – some 1000’ feet out of the nav channel - removed the previous span on January 26 of this year.In mid March a contract was let to replace the span
This is a 320’ span, 2 lanes wide, 32’ high comprised of … CLICKWork was completed in 11 weeks
We’re probably all familiar by now with the big marquee projects that make the headlines in ENR and the other trade publications2 span skewed highway overpass – maybe claimed as the longest 2 span bridge moved in North America
Taking the bridge module 1 step further is to just go ahead and complete the bridge construction before the bridge is ‘placed’This project about 10 miles west of here rolled in the completed bridgeActually, the inverset bridge we saw earlier in Lake Placid was actually the total superstructure
Similarly, a project in Philipston, MA where a single span bridge, at about a 450 skew was rolled into place. A significant difference here is that the new bridge was built on temporary towers over the existing roadway. When fabrication was finished, it was driven straight up (or down) the road to the existing piers. While this did have some impact on traffic during construction of the new bridge – occasional lane closure, lane narrowing, etc - this eliminated the need for a nearby site for prefab and simplified the requirements for the SPMT
.. And this project south of here – on about a 450 skew, AND over railroad tracksAlso on the tour yesterday
No, this is not another big move project, this is the segue to steel bridge modules. This is one of the most visible projects in NYS DOT’s ABP – the redecking of this twin arch bridge carrying I87, the Northway north from Albany. Bids were opened in June, will complete redecking of 1 bound before the snow flies
For starters I will not apologize for the fact this photo is just a little bit out of focus; as I know from 1st hand experience that fab shop conditions are not the most conducive to getting good pictures.This pic was actually taken last Thursday and it shows the steel required for the deck modules. As you can see, the fabrication requirements are very simple and straightforward, and this is typical for the framing under almost all PBUs that use 2 beams in the unit.The beams are W27x94, deck panels are 25’ long, spanning between the arch floor beams. Out to out on the panels is either 8 ‘-3” or 11’-3, depending on their transverse location in the deck”
The poster child for ABC in Massachusetts – I93 fast14This one in Medford - 3 simple spans with the deck cast continuously over the pier
I believe the field trip went to this site yesterday.(Holloway Street over Massachusetts Route 140)3 simple spans with the deck cast continuously over the pier
Here’s another kind of steel beam module. However in this case the steam beam is fabricated from .5” thick plate folded into an open bottom tub shape and then decked w/ C-I-P concrete.You’ll hear more about this tomorrow.
We’ve seen several examples of this prefabricated bridge element
Another one in developmentEither folded plate like the project in Uxbridge, or conventional 5 plate fabrication for longer spansLimited to width of press brake. Beyond 60’, developing a shallow tub fabricated in conventional manner from 5 plates.
And finally, orthotropic deck panels.Maybe not the most economical solution for everyday bridges today, but with the development of standards ..Deck and rib thicknessRib to deck weld, etcWe could get to automated production and the cost would plummet
Conventional fabrication – it’s a time tested technology, now with standard designs. OK; folded plate, orthotropic are newCost premium for ABC is directly a function of accelerated project delivery. If no APD, no premium.Re: shipping weight – can further reduce by using lightweight concrete in the decks