In 2008, the Missouri Department of Transportation (MoDOT) found itself in the unenviable position of having one of the highest percentages of structurally deficient and functionally obsolete bridges of any state in the country. In order to remedy this condition, MoDOT boldly reinvented Alternative Project Delivery (APD) by bundling 554 small bridges into a single design-build contract affectionately known as “Safe & Sound.” MoDOT seized this opportunity to deploy three HCB bridges to investigate a prefabricated bridge system that not only facilitated Accelerated Bridge Construction (ABC) but also provided a sustainable solution to avoid this same predicament in another 50 years. This demonstration project was in part funded by a Highways for LIFE (HfL) grant from the Federal Highway Administration.
Spanning nearly 106 feet, the B0410 Bridge necessitated an HCB 50-percent longer than any other Hillman Composite Beam (HCB®) constructed to date. This posed additional challenges in fabrication, shipping and handling. The demands of this project spawned the advent of the HCB double-web box, comprising two HCBs infused with a monolithic FRP bottom flange and a separate composite top flange adhered to the U-shaped HCB tub. The result is a closed cell box beam, 5-feet tall and 6-feet wide. With greater torsional strength and stability, the double-web HCB allowed for construction of the bridge using only three HCB units for the 30-foot, 8-inch-wide deck.
B0410 was constructed in Dade County north of Lockwood, Missouri, near the end of the Safe & Sound Project. To further compress the construction schedule, the concrete arches in the HCBs were prefilled by Coastal Precast Systems in Chesapeake, Virginia, before shipping to the site on trailing dollies and being placed with two small mobile cranes positioned on either side of Sons Creek.
Extensive instrumentation and studies were also conducted by the Missouri University of Science and Technology, Rolla, as part of a field evaluation of Hillman Composite Girder bridges in Missouri.
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Owner: Missouri Department of Transportation (MoDOT)
Contractor: KTU Constructors/Emery Sapp
Completion date: September 2012
Project Sheet: Click here for downloadable PDF version
“The technical expertise that HCB Inc. provided was fantastic. They answered any questions we had and worked with us to develop some techniques for erecting them. Using HCBs reduced trucking substantially. We were able to move four beams per truckload. If we had used conventional beams, we would have had to use significantly more trucks. Located in a marine environment, Knickerbocker Bridge was a great application for HCBs because it will withstand corrosion better than steel or concrete.”