Owner
Massachusetts Bay Transportation Authority
Client
URS/DMJM + Harris JV
Cost
$550 million USD
Timeframe
January 2003
— January 2008
Services performed
Sub-consultant for NATMÂ design.
Description
Silverline Phase III is an underground extension of the Silver Line from the current terminal at South Station into Downtown Boston. The tunnels through Boston's Chinatown lie up to 25m below surface and include ca. 1400m long-running tunnels, two stations and complex underground junctions. The NATM design alternatives for LRT / Busway tunnels are located beneath existing subway stations and running tunnels. 3D modelling tools were utilised to create multiple alignments.
Geology
Made ground, peat, glacial till (cohesive, plastic), Boston Blue Clay and sand.
Location
Boston, US
Highlights
- NATM tunnelling in difficult ground conditions
- Control of tunnel and structure settlements
- Review of project plans, specifications, estimate and other documents
3D rendering of the Silverline Phase III alignment
NATM alternative beneath MTA's Chinatown Station