The 2017 ASCE Infrastructure Report Card gives the U.S. bridge infrastructure a C+ grade, unchanged from four years ago. More than 56,000 of the nation’s bridges were structurally deficient in 2016, and the report claims “the most recent estimate puts the nation’s backlog of bridge rehabilitation needs at $123 billion.” Read more here.
Short span bridges make up most of the nation’s bridge inventory. With national attention focused once again on America’s crumbling infrastructure, the members of the Short Span Steel Bridge Alliance (SSSBA) offer these proven cost-effective and time-saving solutions for raising the grade:
Tub girder technology. The press-brake-formed steel tub girder (PBTG) system is an innovative short span design solution that resulted from a challenge by the Federal Highway Administration to the steel industry. The system consists of modular galvanized shallow trapezoidal boxes fabricated from cold-bent structural steel plate. 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 Accelerated Bridge Construction (ABC) 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, and
- Is simple to fabricate, requiring very little welding.
PBTG bridges can be installed by local crews and do not require specialized equipment. The first PBTG bridge was constructed in Buchanan County, Iowa in 2015, and another is being built this month in Muskingum County, Ohio. Two more are scheduled for installation in West Virginia later this year. Read more about the PBTG system here.
Free customized project design tool. SSSBA members and their industry partners developed a free-to-use, web-based short span steel bridge design tool ― eSPAN140 ― that delivers preliminary customized solutions in three easy steps. Users can access the tool at www.eSPAN140.com and fill in a few basic parameters for their project. The tool provides a customized Solutions Book that includes:
- Standard designs for rolled beam, plate girder, corrugated structural plate, and corrugated steel pipe,
- Manufacturers’ customized prefabricated solutions,
- Durability solutions,
- The names and contact information for individuals and companies that can design and build the bridge, and
- Access to complimentary design support from experts at SSSBA’s Bridge Technology Center.
To date, more than 2,750 preliminary designs have been delivered to bridge owners and designers by eSPAN140. The Jesup South Bridge in Buchanan County, Iowa was the first bridge built in the U.S. with an eSPAN140 design. Read more here.
Free short span steel bridge design workshops. The SSSBA provides complimentary half-day or full-day workshops on short span steel bridge design to state and tribal Local Technical Assistance Programs (LTAPs). Topics covered include practical and cost-effective steel bridge design and fabrication with eSPAN140, press-brake-formed steel tub girders, steel buried bridge design, galvanized coating solutions, and economical design with case studies. View a sample agenda here. For more information, contact SSSBA Director Rich Tavoletti at firstname.lastname@example.org.
Information on nontraditional design solutions – steel buried bridges. Steel buried bridges are a viable design option in almost all cases where a traditional bridge is used, and are particularly useful in the 25-foot to 80-foot span range. They are durable and resilient, with the ability to support very heavy loads such as mining shovels, large off-road trucks weighing over one million pounds, and freight train loads. They take advantage of ABC practices and can be built with local crews using their own equipment. Many buried bridges can be built in two days or less, excluding foundation work. Since the steel plates stack easily, in most cases they can be shipped to the project site on a single truck, saving shipping costs and reducing environmental impacts.
Recently, Buchanan County, Iowa replaced its 200th Street Bridge with a steel buried bridge, using a local crew which had never worked on this type of project before. The fabricator, county engineer and contractor who worked on this project comment on their experiences in a new video. Watch the video here.
A free webinar on steel buried bridge design is being offered in conjunction with Infrastructure Week 2017. The webinar, “Introduction to Structural Design of Steel Buried Bridges (Non-Seismic),” will be held on May 18 at 11:00 a.m. EDT, and offers 1 LU or 1 PDH. More information and registration details are available here.
On a day-to-day basis, bridge design professionals and owners in the U.S. face a daunting bridge repair and replacement challenge with limited time and resources. They consistently deliver creative and cost-saving solutions despite these limitations. The Short Span Steel Bridge Alliance and its steel partners are committed to helping them achieve their objectives with cost-effective, time-saving steel solutions. For more information, including research on cost savings and the life cycle benefits of choosing steel, visit www.shortspansteelbridges.org. Working together, we can rebuild the nation’s bridge infrastructure and improve its overall grade point average.