A five-volume report produced by a professor from West Virginia University that details a new approach to developing and testing short-span bridges is gaining world-wide recognition.
The report, “Development and Experimental Testing of Press-Brake-Formed Steel Tub Girders for Short Span Bridge Applications,” was compiled by Karl Barth, Samples Distinguished Professor of Engineering in the Department of Civil and Environmental Engineering, and his former doctoral research assistant, Greg Michaelson, who is now on the faculty at Marshall University, and published by the Short Span Steel Bridge Alliance.
The research has been recognized by several trade journals including “Civil + Structural Engineer,” “Equipment World” and “Bridge Design & Engineering.”
The PBGT system uses modular galvanized trapezoidal boxes fabricated from cold-bent structural-steel plates that can be constructed using either galvanized or weathering steel. The concrete deck is precast on the girder and the modular unit is shipped by truck to the bridge site.
According to Barth, the report is really making an impact on the industry.
“The system offers several advantages over traditional short span steel bridge solutions,” Barth said. “The girder requires very little welding and can be produced in 45 minutes. The system’s modular composite design requires less use of stiffeners or cross frames and due to its modular nature, it can be shipped directly to the bridge site, resulting in less construction time and traffic interruptions.
“These and other benefits are generating interest from bridge owners, engineers and other design professionals both here and abroad who are looking for cost-effective solutions to their bridge infrastructure challenges.”
SSSBA hopes that by publishing the research, PBGT bridges will become a common solution for federal, state and local jurisdictions that need to replace many bridges quickly and economically.
One such bridge is the Amish Sawmill Bridge in Buchanan County, Iowa. The original bridge, constructed in 1966 on abutments from a previous bridge, was deemed structurally deficient and functionally obsolete by inspectors in 2015. Construction on the bridge, the first to utilize the PBGT technology, began in the summer of 2015 and was completed by December 2015. Testing was done in 2016 and found that the PBGT exhibit consistent performance, and are a practical option in the short span bridge industry, especially when paired with accelerated bridge construction methods.