U-Link prepares to receive its TBMs Mar 2011
Sound Transit News Release
- Three TBMs to be used on the University Link extension of the Sound Transit LRT system in Seattle, Washington, are due to arrive on site during the coming months and to being their tunnel drives by mid-year.
Capitol Hill EPBM ready for delivery in Japan
- The Hitachi Zosen EPBM ordered by the Jay Dee/Coluccio/Michels JV for contract U230 has been formally accepted in Japan and will ship in the coming weeks. The 21ft 2in (6.5m) o.d. machine will complete the two 3,800ft (1.1km) running tunnels from the Capitol Hill open cut station box to a reception shaft on the far side of the I-5 Interstate highway where they will join with the existing Sound Transit LRT bus tunnel under downtown Seattle.
- Once the TBM parts arrive at the Seattle port in early April, it will be trucked to site and assembled at the bottom of the 80ft (25m) deep station box ready for a launch at the tunnel eye of the first drive in about July. After completing the first drive the machine will return to the station box to complete the parallel drive.
- The TBM will progress on a maximum 5% down gradient for the two drives and operate under an expect pressure of about 1.7 bar. Mucking out behind the machine is specified as continuous conveyor and there are volume weighers on the transfer belt conveyor that are also specified.
- On site at Capitol Hill, the first of five pours for the station base slab was poured last Saturday with 20 to 25 trucks/hr delivering the 900m3 of concrete needed. Excavation of the TBM retrieval shaft at Pine Street is at about 20ft deep and will continue until early summer.
The twin set of Herrenknecht EPBMs for contract U220 in the final phases of testing
- Meanwhile, at the University of Washington station job site to the north, about 99% of the southern portion of the open-cut station box is complete and the Traylor Bros/Frontier-Kemper JV is preparing to pour the 10ft thick concrete slab that will create the floor for the TBM tunneling operations.
- This will require about 7,000m3 concrete and more than 1 million pounds of rebar. The work is to be completed by March/April 2011. Traylor/Frontier-Kemper has selected two Herrenknecht EPBMs for the twin 2-mile (3km) tunnels for Contract U220 to Capitol Hill and these are nearing final assembly and testing at a manufacturing facility in Tacoma, south of Seattle.
- At the same time production of tunnel segments for both contracts has been progressing a pace. By the end of January the casting yard, set up by the Traylor Bros/Technopref JV in Tacoma, had procuded about 1,400 segment rings or about 31% of the total needed for the two contracts.
Mobilization of Seattle's U-Link extension - TunnelTalk, July 2010
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