Mortenson Construction Completes Tunnel on Milwaukee Regional Medical Center Campus
Mortenson replaced the existing tunnel with one that is 230 feet long and 6 feet wide by 6 feet and 6 inches tall, with 9-inch thick walls and a lid. The tunnel is completely walkable and waterproof, was built in just over four months, and is designed to last 50 years.
On the project, Mortenson self-performed the precast concrete panels for the first time on a Wisconsin project. The tunnel’s concrete includes a xypex additive, stainless and epoxy reinforcement and exterior waterproofing for a water-resistant tunnel. The team used new Peri formwork for cast in place wall sections.
In total, the team installed 21 precast lids that were 10 feet by 7 feet 6 inches by 9 inches. The Mortenson team cast each of the panels on site in groups of four at a time. All 20 panels were then set in eight hours utilizing a 75-ton crane and a self-perform concrete team.
Mortenson worked with trade partners Veit and Martin Petersen to demo the existing tunnel and steam pipe by working around existing underground and exposed power/telecom utilities on the site. This was accomplished with zero service disruptions. The team was able to get the new steam tunnel operational 10 days early.