UFC 3-220-01N
15 AUGUST 2005
characteristics and their shear strengths on thawing. Criteria for frost susceptibility
based on percentage by weight finer than 0.02 mm are presented in Reference 20.
These criteria have also been developed for pavements. Heave potential at the lower
limits of frost susceptibility determined by these criteria is not zero, although it is
generally low to negligible from the point of view of pavement applications. Applicability
of these criteria to foundation design will vary, depending upon the nature and
requirements of the particular construction. Relative frost-heaving qualities of various
soils are shown in UFC 3-220-10N.
11-2.3.1.1 Permafrost Soils. Permafrost soils cover the entire range of types from
very coarse, boulder strewn glacial drift to clays and organic soils. Strength properties
of frozen soils are dependent on such variables as gradation, density, degree of
saturation, ice content, unfrozen moisture content, temperature, dissolved soils, and
rate of loading. Frozen soils characteristically exhibit creep at stresses as low as 5 to
10 percent of the rupture strength in rapid loading. Typical strength and creep
relationships are described in UFC 3-130-01.
Figure 11-2 Ground Temperatures During Freezing Season in Limestone, Maine
11-5
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