Snapshot
Highway construction behind TBM Bertha
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 |
| Tunnel design: | Mega-EPBM, 17.48m o.d., to drive the 2.7km highway tunnel under the streets of downtown Seattle |
| Internal structures: | Two road decks, side walls, and equipment rooms |
| Internal structure progress: | In-situ concrete structures cast in 54ft sections |
| Upper road deck: | Cast in place |
| Lower road deck: | Precast panels installed once TBM tunneling is complete and all TBM service lines are removed |
| Revised schedule: | TBM excavation completed by early 2017 Highway tunnel to open by end of 2018 |
