TM 5-852-1/AFR 88-19, Volume 1
CHAPTER 5
FACILITIES ENGINEERING IN AREAS OF DEEP SEASONAL FROST AND PERMAFROST
surface, the amount of solar radiation reaching the
5-1.
General
surface, the wind structure and velocity above the
surface and the surface roughness, the air temperature
a. In the Arctic and Subarctic, engineering
and humidity as a function of height above the surface,
features such as pavements, foundations of structures,
precipitation, snow cover, and evapotranspiration from
walls, utilities and pipelines, underground facilities,
vegetation. Geothermal heat flow toward the surface
excavations and embankments, and drainage facilities
from below is also a factor. These factors are further
must be designed and constructed with proper
discussed in TM 5-852-6/AFR 88-19, Volume 6.
consideration for the special conditions prevailing in
Stripping away, compressing, or otherwise changing the
those areas, as described in chapters 2 and 4.
existing vegetative ground cover and erecting structures
Guidance and criteria for the design and construction of
or constructing pavements, pipelines or other features
facilities in the Arctic and Subarctic are given in the
will alter the thermal balance in the ground. The depth of
remainder of the manuals in the Arctic and Subarctic
annual freeze and thaw will change, and in permafrost
Construction series, TM 5-852-2 through 7, and 9/AFR
areas the depth to the permafrost table will be altered.
88-19, Volume 2, 5 and 6/AFM 88-19, Chap. 3, 4, 7 and
Permafrost degradation or aggradation may occur.
9.
Figure 5-1 shows permafrost degradation measured
b. One of the most important things in any civil
under different surface conditions over a 26-year period
engineering work in the Arctic and Subarctic is the effect
at Fairbanks, Alaska. Permafrost remained stable under
of surface conditions upon the thermal regime in the
the undisturbed, tree-covered area throughout the
ground. Transfer of heat at the air-ground interface is
period.
dependent on such time-varying factors as the thermal
properties of the soil, the albedo (reflectivity) and
insulating properties of the ground cover at the
U.S. Army Corps of Engineers
Figure 5-1. Permafrost degradation under different surface treatments over a 26-year period at Fairbanks, Alaska.
5-1
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