Bridging the Gap Between Economics and Innovation
| February 07, 2014 |
When Iowa’s Jesup Bridge became a safety hazard, the local agency found a way to design and fund reconstruction of this important thoroughfare.
The Jesup Bridge in Buchanan County, Iowa, has been a vital market link for farmers, growers and the community as a whole since it was constructed in the late 1940s. According to the Iowa Department of Transportation, an average of 4,360 vehicles cross this bridge every single day between rural Jesup, Iowa and Highway 20, which leads to the city.
This might seem like small potatoes to a big city or municipality, but for this rural county bridge, this is considered heavy traffic. The loss of this bridge could effectively isolate the residents of this community and cause severe economic duress, and that’s exactly what happened.
The 22-foot-wide concrete bridge became functionally obsolete, too narrow to handle two-way traffic. Buchanan County Engineer Brian Keierleber said the bridge had a sufficiency rating of 49 out of 100. With increasing frequency, agricultural loads could not cross the structure because they were too wide. In fact, any large vehicle made this a single-lane bridge. For one of the most heavily traveled roads in the county, this was a major safety issue and an economic impediment.
Load capacity has also been an issue throughout time. Nearly 25 years ago, Buchanan County drove H pilings through the deck and braced the beams to increase the weight bearing capacity.
“In 2013, the bridge was once again rated as obsolete for its intended purpose and was in clear need of replacement,” Keierleber says. “There existed an obvious detrimental impact to the community, and it needed to be addressed.”
Creative funding for quick action
Like any municipal project, funding a new bridge is a major undertaking. Estimated at nearly $250,000, finding the money would require some creativity. With a sufficiency rating below 50, something needed to be done quickly, and federal funding would take too long.
Fortunately for Buchanan County, Keierleber is South Central Vice President of the National Association of County Engineers (NACE) and sits on several other industry committees, which exposes him to the latest construction ideas and product developments. It was here he saw an opportunity to design and help fund an innovative Jesup Bridge.
New software, eSPAN140, is a free, web-based, design tool utilizing standard designs and details for short-span steel bridges and/or buried soil structures up to 140 feet long. It creates customized steel-bridge design solutions with results defined in less than five minutes, according to Mike Engestrom, chairman of SSSBA and technical marketing director for Nucor-Yamato Steel. The software was developed by two college professors and brought to market by the Short Span Steel Bridge Alliance (SSSBA).
Keierleber realized the SSSBA needed to have someone design and build a bridge using the software to showcase its capabilities and benefits. He also recognized the speed with which a galvanized steel bridge could be erected would serve his needs perfectly.
To design the bridge, Keierleber typed in the specifications for his project – including bridge span length, the number of striped traffic lanes, roadway and width and skew angle – and received a steel bridge design solution in less than five minutes
The new, state-of-the-art, galvanized, short-span, steel 40-foot-wide Jesup Bridge became a demonstration/research bridge project in cooperation with West Virginia University, the University of Wyoming and Iowa State University. (For more information about this partnership, visit betterroads.com/jesup-bridge.)
This cooperative research effort meant that the cost of the new bridge could be subsidized with grants and donations from SSSBA members. The steel, the fabrication and the hot-dip galvanizing corrosion protection were all donated. The new bridge would end up costing Buchanan County less than $100,000 for installation.
The original bridge was demolished on Aug. 20, 2013, and the new, modern, functional bridge was dedicated and opened to traffic on Nov. 11, 2013. With creativity, the problem was solved in a two months.
The American Galvanizers Association and several individual galvanizer members are also involved with county engineering associations and the SSSBA, so they became involved in “100 Year Bridge” discussions and in the education of county engineers about the sustainability, durability and corrosion protection provided by hot-dip galvanizing. The donation of the galvanizing for the Jesup Bridge was an opportunity to demonstrate these attributes and provide a tool for continued research that will benefit taxpayers across the entire United States.
“Without a doubt, Buchanan County will certainly build more galvanized steel bridges,” Keierleber says. Galvanized steel fits in the 100-year design concept that has been adopted in Buchanan County, Iowa. Galvanized steel beams and rebar are key components in this design.
“It all goes back to economics,” Keierleber adds. “It will dictate everything we do. It goes back to cost comparisons and being worried about cost savings in the long run instead of the short term.”
Local labor, local jobs
Beyond research, this project is an enhancement to the community because it removes a barrier to commerce and mobility for county residents. It also provided jobs and income for local county crews, which essentially handled the entire bridge replacement. Typically, contractors are hired for this job, but Keierleber wanted his crews to be intimately familiar with the construction of this bridge. To further involve the community and keep them informed of the bridge and its progress, a live webcam was used.
The use of the eSPAN140 software for bridge design was unique to this project. Using this tool meant the county didn’t have to wait for an engineering firm to produce various designs. After successfully erecting the Jesup Bridge using this tool, county engineers can now be confident in designing a bridge to their specific needs and then being able to share it with others, even though a rendering may not be complete. Additionally, based upon geographic location, the software is programmed to consider typical production and stocking patterns of local steel mills and service centers to ensure material availability.
“Since the bridge has been open, it has relatively uneventful, which is a good thing,” Keierleber says. “There are no more combines getting stuck. Reconstruction of the bridge has had a huge [positive] impact on the community.”
Testing out the software and knowing the county no longer has to be as reliant on federal funding has also made a significant impact, Keierleber says. “Now we can go online and preliminarily design our bridge.”
Demonstration Project Team
• U.S. Bridge: Bridge Superstructure Fabrication, Railing Materials and Fabrication, Steel Detailing
• Nucor-Yamato Steel: Rolled Beams/Girders
• Skyline Steel: H-piles for the Integral Abutment system
• AZZ Galvanizing: Galvanizing
• Nucor Fastener/Ziegler Bolt & Part Co.: Superstructure and Rail Fasteners
• St. Louis Screw and Bolt: Shear Studs
• BlueArc Stud Welding: Stud Welding
• D-Mac Industries: Stay-in-Place Forms
• Gerdau – Memphis Reinforcing Steel: Rebar
• Buchanan County, Iowa: Installation/Demolition
• West Virginia University: eSPAN140 development
• University of Wyoming: eSPAN140 development and Iowa bridge research
• Iowa State University: Iowa bridge research and project coordination
For more information:
• American Galvanizers Association: galvanizeit.org
• Creating the Buchanan County Bridge Design with eSPAN140 blog: betterroads.com/jesup-bridge
• eSPAN140: espan140.com
• eSPAN140 presentation by Dr. Michael Barker, University of Wyoming: teamconference.org/2013/Short_Span_Steel_Bridges.pdf
• Iowa Department of Transportation news: news.iowadot.gov
• Short Span Steel Bridge Alliance (SSSBA): shortspansteelbridges.org
For more articles from the Better Roads “Better Bridges” section, including its “Annual Bridge Inventory,” go to betterroads.com/category/technology-2/better-bridges.