Frozen soil barrier technology. Innovative technology summary report

The technology of using refrigeration to freeze soils has been employed in large-scale engineering projects for a number of years. This technology bonds soils to give load-bearing strength during construction; to seal tunnels, mine shafts, and other subsurface structures against flooding from groundwater; and to stabilize soils during excavation. Examples of modern applications include several large subway, highway, and water supply tunnels. Ground freezing to form subsurface frozen soil barriers is an innovative technology designed to contain hazardous and radioactive contaminants in soils and groundwater. Frozen soil barriers that provide complete containment ({open_quotes}V{close_quotes}configuration) are formed by drilling and installing refrigerant piping (on 8-ft centers) horizontally at approximately 45{degrees} angles for sides and vertically for ends and then recirculating an environmentally safe refrigerant solution through the piping to freeze the soil porewater. Freeze plants are used to keep the containment structure at subfreezing temperatures. A full-scale containment structure was demonstrated from May 12 to October 10, 1994, at a nonhazardous site on SEG property on Gallaher Road, Oak Ridge, Tennessee