to enter into the discussions of the 3,1.1 Structure problem at Eniwetok.
The details of the foundation problems on Military Structures are covered
in the Construction Section of this report (Vol. III) as H&N's activities
in this regard were limited to construction,
Samples were obtained by the H&N foundation experts sent to the Jobsite, Exploration was carried out at the various sites proposed for the
heavy tower discussed above. However, in order to expedite design to the
maximum degree possible, because of the shortages of critical materials
which were then becoming evident, it was necessary in order to secure
materials to require the H&N consultants to make recommendations based
upon engineering experience upon their kmowledge of the soils at the time
of visual inspections of site conditions, before laboratory test aralyses
were completed, This was done and the foundation designs recommended
were later confirmed by the analysis of laboratory test data before the
erection of the tower. A formal report was submitted later.
In order to insure restriction of tower deflections to the allowable
limit, the decision was made to use piling for support of the foundations.
Pile capacity curves were computed and are reproduced in Figure 5.9-5.

Pile driving specifications were written and are presented as Figure 5.9-6.
H&N elected to employ on the foundation designs le-inch steel H piles,

fifty feet long, loaded to 87 tons per pile; however, upon driving the

first piles, a driving resistance lower than anticipated was developed to
the required fifty foot depth. A tem-foot section was spliced to the top
of the driven piles and further driving, to a total depth of 60 feet below
ground, was accomplished; at which point the higher driving resistances
required were developed. Discussions were had at this time which resulted
in the decision that, while 50-foot pile lengths were most certainly adequate for the design loads, in view of the low resistance encountered in

driving the first piles, it would be advisable to use 60-foot piles where

necessary to obtain specified resistances and to obtain an expert review
of the driving records on the balance of the piles.

The exploration carried on in connection with this foundation problem
included the drilling of a total of fourteen borings to a depth reaching

from seven to 53+ feet below the ground surface and the collection of un-

disturbed core samples and representative loose samples. The types of
soils encountered were classified by visual and textural examinations in
the field which were later supplemented by tests and laboratory inspection.

The locations of the borings are shown in Figures 5.97, 5.98, and 5.9-9

in terms of the coordinate system established on each island. Logs of the
soils encountered are reproduced in Figures 5.9-10 through 5.9~16, The

depths at which both types of samples, (i.e. cores and loose samples) were
obtained are indicated on the logs.

The undisturbed core samples were

subjected to a series of tests to determine the strengths and compressi-

bilities of the soil,

Direct sheer, friction, and consolidation tests

were performed,
In conjunction with these tests the moisture content and
densities of the samples were determined, The results of the sheer tests
and of the associated moisture and density determinations are shown on
the graph appearing at the left of the log of each boring in the manner
described by the key to test data in Figure 5.9-17, The summary of the
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