TM 5-852-4/AFM 88-19, Chap. 4
CHAPTER 4
FOUNDATION DESIGN
foundation type are similar to those in seasonal frost
4-1. Selection of foundation type. As illustrated figure
areas of the temperate zones except that difficulties and
4-1, site data, engineering policies, general and
expense involved in preventing uplift or thrust damage
environmental criteria, cost limitations, knowledge of the
from frost heave, as by placing footing below the annual
state-of-the-art, and specific facility requirements are
frost zone, are intensified. In permafrost areas, however,
used to develop the engineering design.
Cost
the selection of foundation type is more complex; it is
comparisons should be made for realistically competitive
rarely practical here to carry footings below the zone of
alternate designs. Feedback may occur at all stages of
frozen ground and additional factors must be considered
the procedure, resulting in a new or modified
86,201
. The principal foundation design options
in design
approaches, design refinements and revised cost
for foundations on permafrost are illustrated in figure 4-2.
estimates, within constraints established by the basic
For areas of deep frost penetration without permafrost
data. Selection is finally made of the foundation type
the design alternatives are similar, except that the
which most effectively meets requirements at minimum
possibility of permafrost degradation does not have to be
cost, and design drawings and specifications are
considered.
completed for this type. Accurate cost estimates require
a. Construction when foundation supporting
full development of the design details covered in
conditions will not be adversely affected by thaw.
succeeding chapters of the manual, as applicable.
(1) Whenever possible, structures in arctic
However, the designer should begin to make at least
and subarctic areas should be located on clean,
rough cost estimates early in the design process in order
granular, non-frost-susceptible materials or rock which
to insure that efforts are applied along avenues most
are free of ground ice. In absence of subsurface
likely to produce economical results. In subarctic areas
exploration, per-
without permafrost, procedures for selection of
U. S. Army Corps of Engineers
Figure 4-1. Design of foundations in areas of deep frost penetration and permafrost.
4-1
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