 |
| Purchase Information |
| Use this form to request purchase information on ASTM online subscriptions. |
|
|
Document ASTM D 5311 is offered by IHS as part of an online subscription. This subscription contains many documents on the same topic.
You may also purchase this document alone from the IHS Standards Store.
ASTM D 5311 Document Information:
Title
Standard Test Method for Load Controlled Cyclic Triaxial Strength of Soil
ASTM International
Publication Date:
Oct 15, 1992
Scope:
This test method covers the determination of the cyclic strength
(sometimes called the liquefaction
potential) of saturated soils in either undisturbed or reconstituted
states by the load-controlled
cyclic triaxial technique.
The cyclic strength of a soil is evaluated relative to a number of
factors, including: the
development of axial strain, magnitude of applied cyclic stress,
number of cycles of stress
application, development of excess pore-water pressure, and state of
effective stress. A
comprehensive review of factors affecting cyclic triaxial test results
is contained in the
literature (1).(Footnote 2)
Cyclic triaxial strength tests are conducted under undrained
conditions to simulate essentially
undrained field conditions during earthquake or other cyclic loading.
Cyclic triaxial strength tests are destructive. Failure may be defined
on the basis of the number
of stress cycles required to reach a limiting strain or 100 % pore
pressure ratio. See Section 3
for Terminology.
This test method is generally applicable for testing cohesionless free
draining soils of relatively
high permeability. When testing well-graded materials, silts, or
clays, it should be recognized
that pore-water pressures monitored at the specimen ends to not in
general represent pore-water
pressure values throughout the specimen. However, this test method may
be followed when testing
most soil types if care is taken to ensure that problem soils receive
special consideration when
tested and when test results are evaluated.
There are certain limitations inherent in using cyclic triaxial tests
to simulate the stress and
strain conditions of a soil element in the field during an earthquake.
Nonuniform stress conditions within the test specimen are imposed by
the specimen end platens. This
can cause a redistribution of void ratio within the specimen during
the test.
A 90° change in the direction of the major principal stress occurs
during the two halves of the
loading cycle on isotropically consolidated specimens.
The maximum cyclic shear stress that can be applied to the specimen is
controlled by the stress
conditions at the end of consolidation and the pore-water pressures
generated during testing. For
an isotropically consolidated contractive (volume decreasing) specimen
tested in cyclic
compression, the maximum cyclic shear stress that can be applied to
the specimen is equal to
one-half of the initial total axial pressure. Since cohesionless soils
are not capable of taking
tension, cyclic shear stresses greater than this value tend to lift
the top platen from the soil
specimen. Also, as the pore-water pressure increases during tests
performed on isotropically
consolidated specimens, the effective confining pressure is reduced,
contributing to the tendency
of the specimen to neck during the extension portion of the load
cycle, invalidating test results
beyond that point.
While it is advised that the best possible undisturbed specimens be
obtained for cyclic strength
testing, it is sometimes necessary to reconstitute soil specimens. It
has been shown that different
methods of reconstituting specimens to the same density may result in
significantly different
cyclic strengths. Also, undisturbed specimens will almost always be
stronger than reconstituted
specimens.
The interaction between the specimen, membrane, and confining fluid
has an influence on cyclic
behavior. Membrane compliance effects cannot be readily accounted for
in the test procedure or in
interpretation of test results. Changes in pore-water pressure can
cause changes in membrane
penetration in specimens of cohesionless soils. These changes can
significantly influence the test
results.
The mean total confining pressure is asymmetric during the compression
and extension stress
application when the chamber pressure is constant. This is totally
different from the symmetric
stress in the simple shear case of the level ground liquefaction.
The values stated in both inch-pound and SI units are to be regarded
separately as the standard.
The values given in parentheses are for information only.
This standard does not purport to address all of the safety concerns,
if any, associated with its
use. It is the responsibility of the user of this standard to
establish appropriate safety and
health practices and determine the applicability of regulatory
limitations prior to use.
Footnote 2 - The boldface numbers in parentheses refer to a list of
references at the end of the
text.
Keywords:
- consolidated-undrained tests
- cohesionless soils
- laboratory tests
- liquefaction
- triaxial tests
About IHS
IHS (NYSE: IHS) is a leading global provider of critical technical information, decision-support tools and related services in a number of industries including aerospace and defense, automotive, construction, electronics, and energy. IHS serves customers ranging from large governments and multinational corporations to smaller companies and technical professionals in more than 100 countries. IHS been in business for more than 45 years and employ more than 2,300 people around the world.
