Owner
Central Puget Sound Regional Transit
Client
North Link Transit Partners
Cost
$1.6 billion USD
Timeframe
July 2011
— August 2012
Services performed
Site supervision services, consulting and monitoring.
Description
University Link is a 5km light rail extension that runs in twin-bored tunnels from Downtown Seattle north to the University of Washington, with stations at Capitol Hill and on the University of Washington campus. The project further includes 20 cross passages located in soft ground and a maximum design water head of 60m. To deal with the prevailing geological conditions, specific ground support categories were developed. Steel fiber reinforced initial lining, sheet membrane waterproofing and CIP final lining were utilised.
Geology
The geology along the alignment consists of over-consolidated glacial clay and till with fractured zones, as well as sand and silt layers.
Location
Seattle, USA
Highlights
- Development of ground support categories
- SFR initial lining
- Sheet membrane waterproofing
Cross passage excavation
Propping of TBM tunnel at cross passage
Probe drilling at cross passage
Finished cross passage