With completion of the work, the foundation beneath I-5 is ready for passage of a tunnel boring machine as Sound Transit builds the 3.15 -mile light rail tunnel extension between downtown Seattle and the University of Washington. Crews working for Sound Transit closed the ramp and others in the area about a year ago to perform the underground work.
"The completion of this part of the University Link project is great news for the region's next light rail line, which will move tens of thousands of people every day" said Sound Transit Board Chair and Snohomish County Executive Aaron Reardon. "Finishing on time and under budget also shows our constituents that we're meeting our commitments and being wise stewards of their money."
Contractors from Condon Johnson & Associates won the $19.7-million contract to dig four pits up to 65-foot-deep adjacent to the retaining walls on either side of I-5 near the Olive Way exit ramp to Capitol Hill in Seattle.
After digging the pits, the contractors cut four "windows" into the retaining walls - two on each side of I-5 - for the tunnel boring machine to make its first pass through as early as late 2011 as it travels from Capitol Hill to the Downtown Seattle Transit Tunnel. The windows were filled with material easily removed by the tunnel boring machines, the pits were filled in and the roadway surface was repaved.
Located entirely underground, the $1.9-billion University Link project includes stations at Capitol Hill and the University of Washington and is an extension to the Link light rail line that opened between downtown Seattle and Sea-Tac International Airport last year. University Link is scheduled to open in 2016, adding more than 70,000 riders a day to the system.
Travel times on University Link will be nine minutes between downtown and UW and three minutes between UW and Capitol Hill.