Groundwater cut-off in conjunction with excavation support for the sinking of vertical shafts was the earliest application of ground freezing and remains the most common. For deep mines, no better method of sinking shafts through deep, water-bearing ground has yet been established. However, over the past 20 years, ground freezing has become a versatile tool for both soft ground and hard rock excavation and tunneling.
There are several advantages of ground freezing unique to the construction of vertical shafts. The freeze can be implemented perfectly through the soil/rock interface, which is often the most difficult geology in which to create a groundwater cut-off by other methods. Proper instrumentation can provide assurance of the integrity of the full depth freeze prior to excavation.