Thomson-East Coast Line Uses Ground-Freezing Technology That Brings Winter To Singapore
Marina Bay Sands is no stranger to unconventional events.
But having a huge ice tunnel in the middle of sweltering hot Singapore is certainly new stuff.
Since March this year, the Land Transport Authority (LTA) of Singapore has been building underground ice walls for the Thomson-East Coast Line’s (TEL) Marina Bay Station.
Marina Bay on Ice?
Are they filming a Disney move at the station, or creating a winter wonderland?
Neither. The engineers are just trying to solidify the ground to dig a stretch of tunnel for the TEL.
LTA is using this ground-freezing technology for the first time because the ground around Marina Bay area “consists of old alluvium clay”.
The waterlogged alluvium clay 40 metres underground makes the conventional method of cement grouting difficult to apply.
Cement grouting is the process whereby cracks in granular soil or rocks are filled to increase the strength and stiffness of the rock.
Ice walls will help by stabilising the ground and preventing water seepage during when LTA excavates the ground to build the tunnel.
In this way, TEL construction can proceed without affecting the Circle Line and North-South Line above.
Ground-freezing technology: how does it work?
Freeze pipes are installed in the ground. Chilled brine at -30°C then circulates within the pipes, causing the soil to freeze.
Multiple ice columns then form around the pipes.
Check out how the ice columns will grow and join to form one continuous ice wall in this cool video below.
After the tunnels are constructed, the freeze pipes will be deactivated and the ground will thaw.
Saving the best for last
No winter wonderland can beat the convenience of another MRT line.
Wait for it — the first stage of TEL slated to open in 2019.
The entire TEL will only be fully functional in 2024.
Looks like Christmas didn’t be coming early for the engineers; they really have work cut out for them in the years ahead.