TransportationCentral Subway
A 3.1-mile underground extension of the Market Street subway, delivering twin bored tunnels, three underground stations and a cavern beneath an operating city centre.
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SR 99 Alaskan Way Viaduct Replacement
A four-lane, four-block downtown viaduct built as a structurally independent tunnel beneath a working street.
Deep excavation and temporary works engineering for a cut-and-cover viaduct in a congested downtown core.
A stacked, unbalanced section required staged temporary support, underpinning of existing utilities, and a spoil management plan that kept deliveries flowing on a constrained urban street network.
Scope of work
- Tunnels & Underground Engineering
- Construction Management
- Structural Engineering
Project facts
- Length
- 4 blocks
- Lanes
- 4
- Format
- Cut-and-cover
- Completion
- 2013
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TransportationCentral Subway project details
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