Over the summer, County Prestress & Precast began production of the company’s largest prestress concrete bridge girders made to date at its state-of-the-art indoor production facility located in Janesville, WI. The seven-and-a-half foot tall, 160-foot-long, and 203,000 lb. girders are slated to construct the I-294, Mile Long Bridge in Chicago, IL. Construction is underway at the site, with the expectation that girder deliveries will begin in mid-November 2019. The girders are engineered to mirror a California Wide Flange girder which has been used successfully on the West Coast where earthquakes are prevalent.
The 160-foot girder is only the beginning of County Prestress & Precast flexing its muscle for this massive project. Additionally, the company will be producing 186-foot-long girders that weigh up to 240,000 lbs. In total, County Prestress & Precast will manufacture 275 girders for phase one of the project, with bidding for phase two set for 2020. Phase one includes a bridge that will carry traffic northbound over the Des Plaines River, the Chicago Sanitary and Ship Canal, several roadways, industrial areas and a railway freight yard. Phase two will include the construction of another completely new bridge that will be dedicated to southbound traffic. This larger style girder was specified for the project in order to span wider distances and ease the impact the piers will have on the environment and businesses below.
The primary challenge in manufacturing this girder is its incredible height. Coming in at 7.5 feet high, the girders required County Prestress & Precast's production team to work from special scaffolding and raised platforms. In addition, the girders’ weight required new investments in cranes, rigging equipment, and chains. County Prestress & Precast's prestress team in Janesville, WI is meeting the challenge by utilizing their previous experience with many other large-scale and high-profile projects.
County Prestress & Precast will continue to produce California Wide Flange girders throughout the winter to meet the demands of the monumental Mile Long Bridge.