Artificial ground freezing (AGF): The basics.

Artificial ground freezing (AGF): The basics. 

Artificial ground freezing (AGF) is a reliable method to provide a water cut-off and ground stability in water-bearing ground.

Basically, boreholes are drilled into the ground, where freeze pipes are installed, in which chilled brine is circulated or fluid nitrogen is injected. Thus, after a certain time, the ground near the freeze pipes is frozen, and, as a consequence, its strength improves and it becomes practically watertight. When the frozen areas around the pipes merge, a continuous freeze wall is formed.

More information can be found in: 

https://www.golder.com/insights/artificial-ground-freezing-harnessing-nature-to-manage-ground-risk/

Below you can see a picture of one of my numerical simulations for a freeze wall:

Numerical thermal simulation of ground freezing (2 freeze pipes in the picture)

Here you can watch a video on how ground freezing works:

And here another video from a project in Oslo, Norway: