Steel’s Swift Response: Flood-Damaged Bridge Replaced in 4 Months

Topics: Accelerated, News, Prefabricated

Excerpt and images provided by Modern Steel Construction – Rapid Response: The steel industry’s emergency repair skills ensured a replacement for a flood-damaged upstate New York bridge opened within mere months.

Floods, washed-out roads, and damaged bridges and dams are major inconveniences for any municipality. They’re crushing for a remote town of about 400 in the Adirondack Mountains. Each roadway into the community is essential, and substantial road or bridge damage can
usher in 80-mile detours. The next morning, New York State Department of Transportation (NYSDOT) inspectors surveyed bridges and culverts in the flooded area —including the State Route 28N bridge over Fishing Brook.

The bridge inspection—accessed by way of a side-by-side utility vehicle due to flooding and damage on the surrounding roadways—revealed that a dam breach just upstream of the Route 28N crossing undermined the west abutment of the bridge and created 12 in. of settlement, which damaged the superstructure, deck, and abutment. The existing bridge was built in 1932 and founded on spread footings on dense soil.

Inspection results and a review of the record plans concluded that the existing bridge could not be rehabilitated and needed to be replaced. Bridge replacement projects can typically last more than a year. This one, though, needed to be completed faster. State Route 28N is too crucial a roadway to have a temporary replacement bridge for much longer than a few months, and construction had to be done before the
Adirondack winter set in, which can happen as early as October or November.

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Additional Resources

What are Press Brake Tub Girders?

Press-brake-formed tub girder (PBTG) is a new technology for short span bridge applications. It consists of modular galvanized shallow trapezoidal boxes fabricated from cold-bent structural steel plate (watch fabrication video). A concrete deck is recommended to be precast on the girder and the modular unit can be shipped by truck to the bridge site.

The system utilizes standard plate widths (based on availability) and is optimized to achieve maximum structural capacity, with most of the steel in the bottom flange and increased torsional stiffness. It is a closed system, since the girder is closed at the bottom. It is versatile for multiple-deck options.

The system utilizes Accelerated Bridge Construction practices, since it:
- Can be installed in one or two days
- Is modular, allowing the use of a precast deck
- Is cost-effective―as much as 1/3 less than a standard concrete girder structure
- Is simple to fabricate, requiring very little welding.
The Short Span Steel Bridge Alliance has developed standardized plans using standard plate sizes (60”, 72” 84”, 96”, 108”, 120”). The designs were developed to achieve maximum structural capacity and are available to use in the free-to-use, web-based design tool eSPAN140.

The press-brake-formed tub girder system is open source.

Learn more about press brake tub girders→