University Link Light Rail U230
- Location Washington
MethodsEarth pressure balance tunneling Precast concrete segment lining Concrete pouring
Michels Construction, Inc. was part of an integrated joint venture responsible for executive management field supervision and engineering on the Central Puget Sound Regional Transit Authority's University Link Light Rail Extension Project. The project extends light rail service from Capitol Hill to downtown Seattle and the airport. Michels' scope of work included the excavation and installation of twin precast concrete segment tunnels. Each of the tunnels are approximately 3,800 linear feet, and 18'10" in diameter. They were excavated to depths ranging from more than 13 feet to less than 18 feet, where they crossed underneath Interstate 5. Nearly the entire tunnel alignment consists of horizontal and vertical curves with the tightest curve radius being only 550 feet.