Usuari:Albert SN/proves: diferència entre les revisions

'''Frost heaving''' (or a '''frost heave''') is an upwards swelling of [[soil]] during freezing conditions caused by an increasing presence of [[ice]] as it grows towards the surface, upwards from the depth in the soil where [[freezing]] temperatures have penetrated into the soil (the freezing front or freezing boundary). Ice growth requires a water supply that delivers water to the freezing front via capillary action in certain soils. The weight of overlying soil restrains vertical growth of the ice and can promote the formation of lens-shaped areas of ice within the soil. Yet the force of one or more growing ice lenses is sufficient to lift a layer of soil, as much as {{convert|1|ft|m|abbr=off}} or more. The soil through which water passes to feed the formation of ice lenses must be sufficiently porous to allow [[capillary action]], yet not so porous as to break capillary continuity. Such soil is referred to as "frost susceptible". El Thecreixement growthde ofles icelents lensesde continuallygel consumesconsumeix thecontínuament risingl'aigua waterque atpuja the freezingal front de congelació.<ref name="Taber 1929">