Ground Freezing

Ground Freezing has been carried for groundwater control and excavation support. Two different techniques are used: the open method, which uses liquid nitrogen, and the closed method, where electric plants chill a solution of calcium chloride into the water (brine). Liquid nitrogen evaporates at a temperature of -196 °C, producing a thermic shock on the surrounding groundwater and freezing a cylinder of 1.00 m within 3 to 4 days. Brine circulates into steel pipes at a temperature of approximately -36°C, creating the same cylinder of frozen soil within 3 to 4 weeks.

The main applications of ground freezing are in the field of tunnelling and underpinning. In the last few years the partner of GEODANYA has performed relevant projects in the Benelux and Italy for the construction of cross passages between main tunnels.