When it rains in Milwaukee, dangerous wastewater no longer pours into Lake Michigan, thanks to 9 newly added miles of concrete tunnel built by Shea-Kenny J.V. Planned more than a decade ago by the Milwaukee Metropolitan Sewerage District, the last segment of the tunnel opened in March 2009, adding 27 million gallons of storage capacity to the overall system.
During the final phase of the project, Shea-Kenny crews completed 175 feet of tunnel lining per day, with each section requiring 110 yards of fast-setting, high-strength concrete formulated to the job's exact specifications. The mix was designed to reach 1,200 psi within 8 hours and deliver final strengths of at least 4,000 psi. Recorded 28-day strengths reached as high as 5,500 psi.
The project has earned awards for excellence from the American Public Works Association and the Wisconsin Ready Mixed Concrete Association.
Location: 320 feet below the streets of Milwaukee, Wisconsin
Size: 2 miles of 23-foot tunnel lining
General Contractor: Shea-Kenny J.V., Milwaukee
Concrete Provided: 53,500 yards of high-strength mix specially formulated for this project by Prairie Wisconsin