Barron County Installs Wisconsin’s First Steel Press-Brake Formed Tub Girder Bridge

Photo Credits: Barron County, WI

The construction of Wisconsin’s first steel Press-Brake-Formed Tub Girder (PBFTG) was completed in Barron County, WI earlier this summer. The bridge which passes over the Yellow River and is located on 15^th Avenue in the town of Baron, WI was closed to traffic during construction for roughly 13 weeks.

The bridge construction project began in mid-April 2023 and was finished just a couple of months later in June 2023. The project was funded by the Wisconsin DOT Transportation Local Road Improvement supplemental funds and matching funds from the Town of Barron.

Special thanks to Mark Servi, Highway Commissioner at the Barron County Highway Department, for his leadership to build Wisconsin’s first steel press-brake formed tub girder bridge.

Why Press-Brake Tub Girders?

PBFTG bridge consist of modular galvanized shallow trapezoidal boxes fabricated from cold-bent structural steel plate. In 2015, the first Short Span Steel Bridge Alliance (SSSBA) installation of a PBFTG bridge for a short span application took place in Buchanan County, Iowa – the Amish Sawmill Bridge. Today, 18 states have installed this innovative bridge system.

The success of PBFTG structures can be attributed to the many benefits they offer to bridge owners, including:

• Cost-Effective (as much as 1/3 less than a standard concrete girder structure)
• Ease of Shipment and Fabrication (requires very little welding)
• Modular
• Accelerated Construction (can be installed in less than a day)
• Design Versatility
• Minimal Maintenance During Their Long Service Lives of More Than 100 Years

The underside of bridge reflecting in the water.

Bridge Design and Standards

The 15^th Avenue Bridge was constructed in conjunction with SSSBA member Valmont Structures. According to the bridge design documents, the Fabrication and Workmanship and the Material and Construction components were to conform to the Wisconsin State Standards Specification for Highway and Structure Construction (2022 Edition).

The structures also needed to conform to the Bridge Welding Code, Current Edition from ANSI/AASHTO/AWS. All structural steel was to conform to ASTM A709 and galvanized for advanced corrosion protection.

Underside of tub girders. Looking at pile bent pier.

Bridge Construction

The prime contractor for the project was Larson Construction. Cooper Engineering of Rice Lake completed the design for the project and is performing the construction inspection. Mattison Contractors performed the grading with Monarch Paving completing the asphalt paving.

The construction project featured:

• Installation of U18 x 51’ ft. U-BEAM
• Installation of 18″ GALVANIZED PBFTG w/ SHEAR DEVELOPERS
• Pouring of concrete abutments/pier diaphragms and deck
• Bridge inspection performed by Barron County

Based on feedback from engineers involved, this was considered a unique project that they hope to see more of in the future. With this being the first of its kind in the state of Wisconsin and with more states utilizing the technology, SSSBA will continue to monitor these efforts and provide the industry with the most up to date feedback on how these bridges are performing.

For more information on Valmont Structures and U-Beam bridges, contact Valmont Structures.

Completed bridge

Learn More About Wisconsin’s First PBFTG Bridge

On September 6, the SSSBA and Barron County are hosting a complimentary educational workshop to learn about PBFTG bridges – and other cost-effective short span steel bridges options – including a presentation and tour of the 15th Avenue Bridge.

Register to Attend

Construction Photos

Tub Girders have arrived on-site.

Riprap placed at east abutment.

Placing the last girder on Span 1. Girders had to be spun for correct placement.

Final tub girder getting placed.

Typical metal deck form installation over the top of the tub girders.

Typical edge of deck overhang brackets.

Pier diaphragm rebar.

Concrete deck pour.

Larson reapplied waterproof membrane after abutment gap repair was completed.

Open to traffic!