frozen ground or permafrost

design depth of frost penetration

(1) (North American usage) the mean of the three largest depths of seasonal frost penetration measured during the past thirty years, or the largest depth of seasonal frost penetration beneath a snow-free soil surface measured during the past ten years (2) (Russian usage) the mean of the depths of seasonal frost penetration measured during at least the last ten years with the ground surface free of snow and the groundwater level below the depth of seasonal frost penetration.

desiccation polygon

closed, multi-sided, patterned ground feature formed by desiccation cracks in fine-grained soil material, usually less than 2 meters (6.6 feet) in diameter.

desiccation crack

crack or fissure developed in fine-grained soil material as a result of shrinkage during drying.

depth of zero annual amplitude

the distance from the ground surface downward to the level beneath which there is practically no annual fluctuation in ground temperature.

depth of thaw

the minimum distance between the ground surface and frozen ground at any time during the thawing season in an area subject to seasonal freezing and thawing.

depth of seasonal frost penetration

the maximum thickness of the seasonally frozen layer.

density of frozen ground

the mass of a unit volume of frozen soil or rock.

delayed strength

the failure strength of a material at a given strain rate or after a given period under deviatoric stress.

degree-day (C or F)

a derived unit of measurement used to express the departure of the mean temperature for a day from a given reference (or base) temperature.

degree of saturation

(1) the total degree of saturation of frozen soil is the ratio of the volume of ice and unfrozen water in the soil pores to the volume of the pores (2) the degree of saturation of frozen soil by ice is the ratio of the volume of ice in the soil pores to the volume of the pores.

Pages

Subscribe to RSS - frozen ground or permafrost