submarine gas transmission pipeline across west … · member of strabag group 47 scotts road...
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Member of STRABAG Group
SUBMARINE GAS TRANSMISSION PIPELINEACROSS WEST JURONG CHANNEL
Location: SingaporeClient: Powergas SingaporeEngineer: WorleyParsons Pte Ltd.Construction Period: Feb 2011 to Dec 2012Contract Value: 23.6 Million SGD
PROJECT OVERVIEWThe project includes laying a gas pipeline under the sea, crossing the West Jurong Channel, together with onshore pipelines laid in trenches.
In order to avoid negative impacts of disturbing the seabed by dredging the option to construct by means of tunnelling was chosen. The constructed tunnel provides a sleeve for the installation of the gas pipeline. The tunnel was constructed by pipe jacking.
This method of tunnel construction allowed the size of the tunnel to be kept to a minimum. Once the tunnel was completed, a DN700mm steel gas pipeline was installed inside the tunnel and in the shafts and tied into the onshore pipework.
• Construction of two deep shafts ID14.0m and ID7.5m, with a depth of 30 metres using diaphragm wall construction.
• Construction of a sleeve tunnel with ID2000mm and a length of 1,550m, in one single drive.
• The tunnel works were completed 36 days ahead of schedule.
• Construction of a pipeline crossing the West Jurong Channel without dredging and without obstructing marine traffic was a major achievement and was a first in Singapore.
• Installation of a DN700 steel gas pipeline inside the sleeve tunnel.
• The longest tunnel constructed by pipe jacking method in one single drive in Asia-Pacific Region.
PROJECT HIGHLIGHTS
Member of STRABAG Group
47 Scotts Road#17-02 Goldbell TowersSingapore 228233Phone: +65 6339 0436Fax: +65 6339 [email protected]
GEOLOGY
The geology is mixed with mainly silty, sandy soils with mudstone stretches. Züblin’s Dual Mode machine was perfectly suited for these ground conditions and the tunnel was completed without any problems.
THE CHALLENGENo tunnel of this length has previously been constructed in a single drive in the Asia-Pacific region. Being under the sea, also increases construction risks significantly.
However, by installing intermediate jacking stations and maintaining proper lubrication at all times the TBM and pipe jacking equipment successfully completed the 1,550m drive.
This length is a record for the Asia-Pacific region and is also the world’s 5th longest tunnel constructed by pipe jacking in one single drive.
Jurong West Channel
Mudstone
Silt
Sand Clay