Sentosa Gateway Road Tunnels

Land Transportation Authority

Consulting Services and Tunnel Design:

Gall Zeidler Consultants designed two mined sections of the tunnel to pass under existing major roadways (Telok Blangah Road and Kampong Bahru Road) including the temporary and final support, waterproofing, structural and geotechnical instrumentation and monitoring programs. The remainder of the tunnel will be constructed using cut and cover techniques.

The double–lane, mined road tunnel crosses under Telok Blangah Road between existing bridge piers under a max. overburden of 10 feet (3 meters). It is equipped with an emergency shoulder and walkways. The final structure will be formed by a single-cell reinforced concrete box that will be erected within a temporary steel pipe box structure.

The single–lane, mined road tunnel is equipped with an emergency shoulder and walkways. The tunnel crosses under Kampong Bahru Road in easterly direction, passes under a three–cell concrete culvert with minimal clearance and continues along Keppel Road. Maximum ground cover 26 feet (8 meters).

LOCATION:

Singapore, Singapore

DATE:

2009-Present

STRUCTURE:

Two road tunnels

Length:

1–Lane tunnel 384 feet (117 meters)
2–Lane tunnel 312 feet (95 meters)

CROSS-SECTION:

1–Lane tunnel: approx. 46 x 30 feet (14 x 9 meters) (W x H)
2–Lane tunnel: approx. 35 x 27 (33 at Pump Station) feet (10.8 x 8.1 [10] meters) (W x H)

GEOLOGY:

Predominantly granular soils with layers of cohesive soils, peat, peaty and organic clay, organic sand, residual soil, and sedimentary rocks (below tunnel invert. Groundwater level approximately at 8.2 feet (2.5 meters) below the surface

Cost:

Estimated US $ 40 million

CLIENT:

CPG Consultants

Owner:

Land Transportation Authority