About Project
Gall Zeidler Consultants (GZ) designed two mined sections of the tunnel to pass under the existing major roadways (Telok Blangah Road and Kampong Bahru Road) including the temporary and final support, waterproofing, structural and geotechnical instrumentation, and monitoring programs.
Project Name
Sentosa Gateway Road Tunnels
Location
Singapore, Singapore
Construction Period
2009 – 2015
Contractor
CPG Consultants
Designer
Gall Zeidler Consultants
The double-lane tunnel crosses under Telok Blangah Road between existing bridge piers under a maximum overburden of 8 feet (2.5 meters). It is equipped with an emergency shoulder and walkways. The final structure was formed by a single-cell reinforced concrete box that will be erected within a temporary steel pipe box structure. The single-lane tunnel is equipped with an emergency shoulder and walkways. The tunnel crosses under Kampong Bahru Road in an easterly direction, passes under a three-cell concrete culvert with minimal clearance and continues along Keppel Road with a maximum ground cover of 26 feet (8 meters).
The temporary structure comprised of steel pipes arranged in a box-like pattern. These large diameter 2.7 feet (0.82 meters), heavy steel pipes were used to pre-stabilize the ground surrounding the final tunnel. The steel pipes were installed by micro tunneling methods around the final structure to provide initial ground support. The interlocking pipes were filled with concrete.
The design allowed utilities and roadway traffic operational during tunnel construction.
