FLOOD10393

• County: Statewide
• Basin: Statewide
• Title: Engineering and Design - Design and Contruction of Levees
• Date: 3/31/1978
• Floodplain - Doc Type: Educational/Technical/Reference Information

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EM 1110-2-1913
31 Mar 78

CHAPTER 3

LABORATORY TESTING

3-1. General.

a. Reference should be made to EM 1110-2-1906 (ref. A-3a(7)) for
current soil testing procedures, and to EM 1110-2-1902 (ref. A-3a(4))
for applicability of the various shear strength tests in stability
analyses.

b. Laboratory testing programs for levees will vary from minimal
to extensive, depending on the nature and importance of the project and
on the foundation conditions, how well they are known, and whe-l-her
existing experience and correlations are applicable. Since shear and
other tests to determine the engineering properties of soils are ex-
pensive and time-consuming, testing programs generally consist of water
content and identification tests on most samples and shear, consolida-
tion, and compaction tests only on representative samples of foundation
and borrow materials. It is imperative to use all available data such
as geological and geophysical studies, when selecting representative
samples for testing. Soil tests that may be included in laboratory
testing programs are listed in table 3-1 for fine-grained cohesive soils
and in table 3-2 for pervious soils, together with pertinenturemarks on
purposes and scope of testing.

3-2. Classification and Water Content Determinations. After soil
samples have been obtained in subsurface exploration of levee founda-
tions and borrow areas, the first and essential step is to make visual
classifications and water content determinations on all samples (except
that water content determinations should not be made on clean sands and
gravels) . These samples may be jar or bag samples obtained from test
pits, disturbed or undisturbed drive samples, or auger samples. Field
descriptions, laboratory classifications, and water content values are
used in preparing graphic representations of boring logs. After examin-
ing these data, samples of fine-grained soils are selected for Atterberg
limits tests, and samples of coarse-grained soils for gradation tests.

Section I. Fine-Grained Soils

3-3. Use of Correlations. Comparisons of Atterberg limits values with
natural water contents of foundation soils and use of the plasticity
chart itself (fig. 3-1), together with split-spoon driving resistance,
geological studies, and previous experience often will indicate poten-
tially weak and compressible fine-grained foundation strata and thus the

3-1