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Geological Engineering

Russel Square Escalator Redevelopment

Service Performed
Preliminary design and settlement analysis for various options and layouts.
Commencement - Services
January 31, 1996
Completion - Services
May 31, 1996
Russel Square, London
United Kingdom
Technical data

Preliminary design studies for the construction of a 4-way escalator shaft using NATM. Escalator shaft 11.5 m span, approx. 60 m long by 32 m deep, initial lining 300 mm thick reinforced sprayed concrete.

Geology description

Made Ground, Alluvium, London Clay.

Geology types
Service areas
Geological Engineering, Tunnel Design & Specialities

Beacon Hill Station

Service Performed
NATM / SEM station design and construction supervision.
Estimated cost
Commencement - Services
February 26, 2000
Completion - Services
December 28, 2007
401 S. Jackson Street
Seattle, WA 98104
United States
Technical data

NATM Light Rail Station located 150 ft (46 m) beneath surface. Station complex includes central elevator/access shaft, concourse, opposing platform tunnels and cross passages. Platform Tunnel Section: 36 ft w x 31 ft h; Platform Tunnel Area: 925 sqft (86 m²); total Station Excavation Area: 63,000 sqft (5853 m²).

Geology description

Over-consolidated glacial clay and till with fracutured zones. Intermittent sand and silt layers with perched groundwater.

Geology types

The Beacon Hill Tunnels and Station are part of the 22.5km initial segment of the Sound Transit Central Link Light Rail Line that will establish a high capacity commuter connection from downtown Seattle to Tacoma. The 1300m running tunnel under Beacon Hill will be mined by Earth Pressure Balance Machine (EPB), while the deep mined Station will be constructed using slurry walls and the New Austrian Tunneling Method (NATM), referred to as Sequential Excavation Method (SEM) for this project.

Bid cost
Final cost
Construction methods
Tunneling under
Max Overburden
Min:120 Max:140
Beacon Hill Station layout
Tunnel excavation under way
3D rendering of Beacon Hill Station complex
Platform tunnel cross section
Schwind Thomas
Installation of Vacuum Dewatering
Rendering of Beacon Hill Station
Project number
Final cost
$280 million USD