PHOTOGRAMMETRIC ENGINEERING
FrG. 1. A typical example showing what may
happen if the builder is not familiar with the
permafrost conditions: Bert and Mary's nice little
inn at Richardson Highway between Fairbanks
and Big Delta, Alaska, originally built with a ver-
anda as a coffee-room. Ten months later, however,
useful as a steep-sloping entrance only, to the
settled main building. (Photo by the author
August 24, 1955.)
PERMAFROST PROBLEMS
The seasonal frost is no doubt a problem
for the constructor. It is a small one, however,
compared to the controlling influence of
permafrost on certain engineering projects;
examples are transportation, surface and
underground exploration, construction and
durability of structures in or on permafrost,
water supply, sewage disposal, etc.
Permanently frozen ground is common not
only in the Arctic but in several subarctic
Fi1G. 2. Sorted circles and polygons (center) in
stony terrain, the polygons up to 15 feet (4.5 m.)
across, on North East Land, Svalbard, at 650—800
feet (abt. 200—240 m.) above sea level. (Ground
photo by the author July 30, 1957.)
areas. To ignore permafrost in construction is
to invite delays, expensive repairs, or later
failures (Black).
If proper location and construction meth-
ods are not used, permanently frozen ground
can cause collapse of both roads and build-
ings. Heaving, settling in the thawed ground,
and poor drainage are the main problems.
Figure 1 illustrates what may happen if an
architect is not familiar with permafrost prob-
lems. Neither the landlord nor the builder
had any idea of the presence of permaífrost in
this area of the subarctic region of Alaska.
There was, however, permanently frozen
ground. When the insulating surface was re-
moved, the ground thawed and the main
building, which was constructed with a heavy
concrete footing, settled. If by chance the re-
sult had been heaving instead of settling, an
ice wedge could have broken the floor and ap-
peared in the kitchen!
Permafrost, however, presents not only
many special engineering problems but agri-
cultural problems as well. The less disturb-
ance of the natural insulating vegetation and
soil cover, the better. Farming activities quite
naturally include clearing the surface with
the object of cultivating new fields, which
may be undermined by large ice masses.
Then, when the soil cover is disturbed and
the surface is cleared, the ice melts and ther-
mokarst mounds and pits are formed. Thus
the new fields may eventually become diffi-
cult or impossible to cultivate (Pévé).
F1G. 3. A vast area closely covered with blocks
crumbled through frost action. In this Devils
Acre sorted polygons and sorted circles appeared
everywhere. Ground photo from North East Land,
between Mt. Celsius at Murchison Bay and the
West Ice at abt. 850 feet (250 m.) above sea level.
(Taken by the author July 30, 1957).
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