TM 5-852-4/AFM 88-19, Chap. 4
(3) Example of design of a uniformly
Deformation:
loaded square raft foundation.
Zone A, 0.0313 x 2 ft = 0.0626 ft
Zone B, 0.00158 x 3 ft = 0.0047 ft
Assumptions: assume the same soil conditions
Zone C, 0.0000884 x 6 ft
= 0.0005 ft
as shown in figure 4-62 and a foundation of the general
TOTAL = 0.0678 ft = 0.81
type shown in figure 4-68.
Say 1 in., at end of 25 years.
Determining required depth of base of raft. The
analysis is the same as for the isolated square footing in
The details for the field test of the third method
the preceding example.
are given in paragraph 4-5. Actual data for a field test
Determining the temperature distribution with
under the conditions assumed in this example are not
depth below foundation for critical period of year. The
available. As indicated in paragraph 4-5, the various
analysis is the same as for the isolated square footing in
requirements for the field test make this approach
the preceding example.
difficult to employ and the designer will generally have to
Checking bearing capacity in critical period of
rely on laboratory unconfined compression creep tests in
year.
estimating creep deformation.
U. S. Army Corps of Engineers
Figure 4-66. Conditions for creep analysis.
4-104
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