Paula Wallis, TunnelTalk

Sound Transit has awarded to Jay Dee/Coluccio/Michaels, the JCM U-Link JV, the second tunneling contract for the 3.15 mile University Link (U-Link) light rail system in Seattle. Sound Transit’s Board of Directors approved the contract last Thursday October 22, 2009 with a Notice to Proceed expected by November 4.

Fig 1. University-Link alignment

The JV’s bid of $153.5 million is about 12% below Sound Transit’s original cost estimate for the project. The contract also included a 10% contingency, that could increase the cost to $168.9 million, however Sound Transit reports that it is still $42 million less than the amount set aside for the tunnel section in the budget for the University Link phase of the network.

The contract includes 3,800ft (1.15km) of segmentally lined twin running tunnels between Capital Hill Station and the Pine Street Stub Tunnel (PSST); excavation and initial support of the Capital Hill Station plus five SEM (sequential excavation method) cross-passages at intervals between the pressurized face TBM bored tunnels; construction of a temporary TBM retrieval shaft at the PSST headwall; and completion of the tunnel interfaces with the PSST.

Traylor/ Frontier-Kemper JV holds the first U-Link contract, awarded June 2009 for the alignment from Capitol Hill to the University of Washington. The JV's low bid of $309.2 million for that section came in 22% or $86 million below the Engineer’s $395.35 million estimate.

Meanwhile work is currently underway to prepare the I-5 freeway structure for the coming under pass of the TBM drives for the metro. Crews have started excavating two construction pits of about 60ft deep by 40ft wide (18m x 12m) in the Olive Way off-ramp. They are also installing tie-backs and whalers on the Pike/Pine reversible HOV (high ovvupancy vehicle) lane to minimize wall movement and ground settlement and once completed will excavate similar construction pits to the Olive Way ramp.

With the tunneling contracts awarded, Sound Transit is preparing the community for six years of construction activity. Community outreach includes public presentations that outline the construction schedule, nighttime construction work, truck routes to and from the staging sites, noise levels, and business mitigation measures. Sound Transit is planning a 'meet the contractor' event in the coming weeks as part of its continuing outreach program.

The $1.9 billion University Link is scheduled to open in 2016.

References

Few bids, but trend continues for Seattle's LRT - TunnelTalk, Aug 2009
Keen interest for Seattle’s next LRT bid - TunnelTalk, Aug 2009
Low bid cuts cost of University Link - TunnelTalk, March 2009
Strong competition starts North Link in Seattle - TunnelTalk, Dec 2008
Beacon Hill celebration and investigations - TunnelTalk, Jul 2009

Sound Transit: University Link Light Rail