Steel Press-Brake-Formed Tub Girder
What is a Steel Press-Brake-Formed Tub Girder?
PBFTGs utilize a single steel plate that is strategically bent into a superior structural shape.
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Our environment is changing, and bridges across the United States are deteriorating at a rate which currently outpaces the available funding to slow or reverse deterioration rates. It is estimated that it will take more than 80 years to fix all current structurally compromised bridges considering current federal and state capital investment levels. With service life as low as 35 years for the current baseline practice, the demand for newly constructed bridges will greatly exceed our future capacity.
In addition to not meeting aspirational service life timeframes, each current baseline practice has its own specific associated problem to solve. Steel Press-Brake-Formed Tub Girder (PBFTG) uses proven material and current design standards, combined with new fabrication and construction techniques, to produce a bridge superstructure with reduced maintenance cost and shortened construction time, that lengthens the service life over the current bridge superstructure baseline practice.
PBFTGs utilize a single steel plate that is strategically bent into a superior structural shape. The plate is cold formed into a U shape with a press brake, with each bend occurring along the plate's longitudinal axis. The formed steel plate bend radius exceeds the minimum requirement, based on AISC and ASTM cold forming guidelines, and is designed for infinite fatigue life due to lack of connections and discontinuities. These fabrication advancements further lengthen the service life of the steel tub girder over other fabrication technologies. Additionally, a hot-dipped galvanized coating can be applied to the PBFTG to further lengthen the maintenance-free service life. By applying a Duplex coating, painting over hot-dip galvanized steel, and with appropriate composite concrete bridge deck detailing, PBFTG will meet the AASHTO Committee on Bridges and Structures strategic objectives of extending bridge service life to an anticipated 100 years.
Resources
Contacts
Lead States Team Members
Bradley Wagner, P.E.
Chief Design Engineer
Michigan Department of Transportation
Phone: 517-256-6451
Email:
WagnerB@michigan.gov
Joe Alderson, M.S. & P.E.
Structural Project Manager
Missouri Department of Transportation
Central Office – Bridge Division
Phone: 573-522-8722
Email:
Joseph.Alderson@modot.mo.gov
Timothy Leaf, P.E.
Structural Project Manager
Missouri Department of Transportation
Central Office – Bridge Division
Phone: 573-526-1505
Email:Timothy.Leaf@modot.mo.gov
Guozhou Li, P.E.
Assistant Chief Bridge Engineer
Pennsylvania Department of Transportation - Bridge Office
Phone: 717-214-8773
Email:
guli@pa.gov
Friend of Lead States Team
Guy Nelson, P.E., S.E.
Structural Engineer
Product Development Director
Valmont Structures*
*Note that AASHTO does not endorse, recommend or promote any specific proprietary product. Proprietary product names are mentioned for information purposes only and does not constitute an endorsement or recommendation by AASHTO.
