TBM Bertha ready for New Year restart
  • CREG

30 Dec 2015: Todd Trepanier, Program Administrator of the Alaskan Way viaduct replacement tunnel project in Seattle for the Washington State Department of Transportation (WSDOT), and Chris Dixon, Project Manager for construction JV Seattle Tunnel Partners (STP), held a press briefing on 23 December 2015 to describe in detail the plan for relaunching TBM Bertha after its two-year long repair process. The 17.48m diameter mega-TBM is to mine through the north wall of the recovery shaft during this week, the last week of 2015 and the first week of 2016, to complete the remaining 8,000ft (2,450m) of its total 9,000ft (2.7km) drive during 2016.

References
Alaskan Way bored tunnel alignment - video report - TunnelCast, October 2010
Mega-TBM factory tested in Japan – video report - TunnelCast, Dec 2012
Technical details of record setting TBM–video report - TunnelTalk, Dec 2013
TBM Bertha suffers main bearing seal failure - TunnelTalk, February 2014

Snapshot

TBM Bertha ready for New Year restart

Sterling Noren reporting for TunnelTalk from Seattle
Project: Alaskan Way Viaduct replacement tunnel, Seattle
Contractor: Seattle Tunnel Partners Dragados - Tutor Perini JV
Client: Washington State Department of Transportation
Project scope: World's largest single-tube, double-deck highway tunnel to replace the earthquake damaged Alaskan Way viaduct across the waterfront of Seattle
Tunnel design: Mega-EPBM, 17.48m o.d., to drive the 2.7km highway tunnel under the streets of downtown Seattle
TBM supplier: Hitachi Zosen 17.48m EPBM
Tunnel lining: Nine segments plus key in each 600mm thick x 2m wide ring
TBM programme: TBM drive started June 2013
Date of breakdown: December 2013
Revised schedule: Remaining 8,000ft programmed to be completed by end of 2016