Definition - What does Ground Freezing mean?
Ground freezing can be defined as the process of freezing the ground around excavations, tunnels, shafts or boreholes in order to stabilize the soil and prevent it from collapsing. This procedure eliminates the need for dewatering especially in places with high groundwater table. This method has been successfully used in trenchless construction methods such as microtunneling. In addition to stabilizing loose soil, it also imparts additional compressive strength to the soil.
Trenchlesspedia explains Ground Freezing
In microtunneling, ground freezing is done in order to cut off the groundwater to construct the shaft, for modification of ground at microtunnel boring machine (MTBM) break-in and break-out, and for ground support. Ground freezing can also be used in emergency situations when unforeseen situations such as loose subsurface conditions are encountered.
Ground freezing works by converting the water present in the pores to ice when chilled liquid is circulated in pipes placed in small diameter holes drilled in the ground. The rock and soil particles fuse together to form a frozen mass that is impermeable and acquires good compressive strength. Two commonly used cooling agents are brine and liquid nitrogen.