The $32.7 million rehabilitation of two Interstate 74 bridges over a local street and rail tracks in Champaign-Urbana, Illinois, is nearing completion.

“The project was undertaken to repair deteriorated bridge decks and failed expansion joints,” says Jason Smith, Supervising Construction Field Engineer, Project Implementation/Construction, Illinois Department of Transportation (IDOT) Region 3/District 5.

The bridge carrying traffic over the CN railroad tracks and Illinois Central Railroad yard opened in 1956 and the one at Market Street in 1957. Both were widened in 1992 to add an auxiliary lane. The average daily traffic count stands at 63,100 vehicles.

The project was part of the state’s six-year, $45 billion Rebuild Illinois capital plan, designed to address deteriorated bridge decks, failed expansion joints and low vertical clearances. The plan became law in 2019 and is the largest capital program in Illinois history. It offers $33.2 billion to improve every mode of transportation in every part of the state. Other funds will go toward universities, early childhood centers, and state facilities. The plan is expected to create jobs and grow businesses.

Illinois DOT designed the project and divided it into three stages, starting in August 2020, with the second phase beginning in April 2021, and the final in April 2022.

Sangamo Construction of Springfield, Illinois, received the construction contract in 2020. The company, founded in 1925, remains family owned and operated. The project remains on track to finish in November 2022.

“It’s an aggressive schedule,” says Casey Nell, Project Manager for Sangamo. “Everything seems to be going well.”

The project consists of the replacement of the concrete superstructures of the I-74 bridges over two CN mainline rail tracks, 16 rail yard tracks, and Market Street. The work includes the replacing the bridge decks, parapets, bridge beams – including one that had been damaged at Market Street, and expansion joints, Smith reports. This project features updated guardrails, lighting, and pavement markings. Crews initially installed temporary lighting and pavements. Work progressed on one bridge direction at a time, starting with the eastbound bridges, which opened at the end of 2021.

The railroad bridge is the larger of the two structures, about 730 feet long. The steel-plate girders are more than 6 feet tall and were fabricated at Industrial Steel Construction in Gary, Indiana. “The bridge beams have been galvanized for a longer-lasting life span,” Smith says.

On the railroad bridge, Sangamo removed the old bridge deck and girders, Nell reports. In one area, the expansion joint had failed, likely as a result of road salt and chemicals used in the winter deteriorating the concrete pier. Sangamo replaced those joints. The team also replaced that pier. IDOT had placed temporary shoring towers to hold up the bridge deck until the replacement could be put in place. The team also constructed new abutments, completed numerous concrete structural repairs, and replaced slope walls. Crews poured an 8-inch concrete deck.

The construction has not interfered with train traffic. Sangamo has worked closely with the railroads to coordinate and ensure CN’s safety standards are met. Construction required coordinating with all three entities using the tracks and yard: CN, Amtrak, and the Illinois Central Railroad (ICRR). Crews worked around when trains came through in two-to-four hour windows.

“It’s rare if there is not a train in the yard,” Nell says. “We had to get creative with our windows, like working 24 hours at a time.”

Complicating the work were several large Ameren electric transmission lines crossing where crews were working, which required coordinating outages with the power company when trains were not coming through.

“We’ve been pleased with the partnering effort between Sangamo, IDOT, CN, ICRR, and Ameren to get the structure rebuilt over the rail yard,” Nell says. “Everybody was willing to accommodate each other, even if it was not ideal. Everyone has been willing to come to the table and find a solution. That has been the best aspect of the job so far.”

The bridge over Market Street is about a half mile west of the railroad bridge and is smaller. Sangamo placed rolled beams and will be paving a new concrete deck.

The work includes raising the vertical clearance to avoid future accidents with trucks running into the structure. That entails pouring pier cap extensions, adding 10 inches to 15 inches of concrete to each pier cap.

The project has presented several challenges.

“Access to the site has been one challenge,” Smith says. “The contractor has had to be creative to gain access.”

The two bridges are in close proximity, with access from the side of the other bridge cut off. Crews have had to cut in and build access ramps up the slopes, Smith adds.

Another challenge has been the schedule and the need to complete the project by the end of this year.

Sangamo removed the median barrier wall to enable traffic to crossover and allowed crews to maintain two lanes of traffic in each direction on I-74 during daytimes while working to construct one side of each structure. The Neil Street on ramp to I-74 eastbound has been closed due to its proximity to the Market Street bridge.

At certain times at night, one lane will remain open. During the winter, traffic was restored to preconstruction normal. During construction, the department has identified alternate routes eastbound and westbound.

Smith reports being proud of the “safe work zone and the quality of construction. I have been told by many that the completed side is the smoothest bridge deck they have ever traveled.”

Photos courtesy of Sangamo Construction