TM 5-852-4/AFM 88-19, Chap. 4
Table 3-1. Example of Settlement Estimate - Location A, figure 3-7.
Average
Settlement
Cumulative
Depth
pressure
Strain
of layer
settlement
(ft)
(psi)
(in./in.)
(in.)
(in.)
10-15
11.6
0.0o64
3.84
3.84
15-20
13.6
0.036
2.16
6.00
20-25
15.8
0.0425
2.55
8.55
25-30
17.8
0.124
7.44
15.99
30-35
19.6
0.088
5.28
21.27
35-40
21.2
0.071
4.26
25.53
40-45
22.8
0.089
5.34
30.87
45-50
24.3
0.070
4.20
35.07
Notes:
1.
Values for average pressure determined from "Adopted Site Working Curve" in Figure 3-6.
2.
Values of strain for first five layers taken from plots of pressure vs strain in Figure 3-5a for
Exploration A. Values for three lower layers determined from similar plots not shown.
may be expected to consolidate nearly as rapidly as thaw
apparatus of this type and has performed research on
progresses, the rate of settlement will correspond closely
thermal properties of construction materials at below
71
freezing temperatures. Thermal conductivity probes
in time with the rate of thaw. Because the thaw front
108,171
but procedures
have been extensively investigated
under a heated structure advances more rapidly at the
which will produce reliable results under all conditions
center than under the edges, as illustrated in figure 4-9,
have thus far not been developed.
the actual distribution of settlement displacement across
(2) The thermal conductivity of soil is
the foundation normally will develop in a dish shape.
g. Thermal properties. The basic thermal
dependent upon a number of factors such as density;
moisture content; particle shape; temperature; solid
properties of soils and other construction materials
frozen, unfrozen, or partially frozen. The latent heat of
pertinent to foundation design are specific heat, thermal
fusion 6f soil is dependent upon the amount of water in
conductivity and latent heat of fusion. Satisfactory
the voids which actually freezes. The specific heat
values of thermal conductivity and specific heat of these
capacities of soils may be adequately computed by
materials for design computations are available in tables
14
summing the specific heat capacities of each constituent,
and charts of TM 5-852-6, the values for soils and rock
multiplied by its respective mass fraction, taking into
being based primarily on investigations by Kersten."
account moisture phase proportions. Anderson and
Because special equipment is required, special
123
Tice have made detailed investigations of the unfrozen
measurement of perties for design purposes is not
water contents in frozen soils and Anderson and
recommended for normal design situations.
121
have recently summarized other related
Morgenstern
(1) If performance of thermal conductivity
fundamental thermal research since 1963.
tests is required, however, it is recommended that the
119
h. Ground water records.
Knowledge of
guarded hot plate method be used, ASTM C 177, with
surface and
equipment
modified
to maintain
specimen
temperatures below freezing.
CRREL has test
3-11
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