ASTM D7012-07e1
(Test Method)Standard Test Method for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures
Standard Test Method for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures
SIGNIFICANCE AND USE
The parameters obtained from these procedures are in terms of undrained total stress (as already mentioned in 1.1.1.). However, there are some cases where either the rock type or the loading condition of the problem under consideration will require the effective stress or drained parameters be determined.
Unconfined compressive strength of rock is used in many design formulas and is sometimes used as an index property to select the appropriate excavation technique. Deformation and strength of rock are known to be functions of confining pressure. The confined compression test is commonly used to simulate the stress conditions under which most underground rock masses exist. The elastic constants are used to calculate the stress and deformation in rock structures.
The deformation and strength properties of rock cores measured in the laboratory usually do not accurately reflect large-scale in situ properties because the latter are strongly influenced by joints, faults, inhomogeneities, weakness planes, and other factors. Therefore, laboratory values for intact specimens must be employed with proper judgment in engineering applications.
Note 2—Notwithstanding the statements on precision and bias contained in this test method; the measures of precision of these test methods are dependent on the competence of the personnel performing them, and on the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing. Users of this test method are cautioned that compliance with Practice D 3740 does not in itself assure reliable testing. Reliable testing depends on many factors; Practice D 3740 provides a means for evaluating some of those factors.
SCOPE
1.1 This test method covers the determination of the strength of intact rock core specimens in uniaxial compression and confined compression. The tests provide data in determining the strength of rock, namely: the uniaxial strength, shear strengths at varying pressures and varying temperatures, angle of internal friction, (angle of shearing resistance), and cohesion intercept. The test method specifies the apparatus, instrumentation, and procedures for determining the stress-axial strain and the stress-lateral strain curves, as well as Young's modulus, E, and Poisson's ratio, υ. It should be observed that this method makes no provision for pore pressure measurements and specimens are undrained (platens are not vented). Thus the strength values determined are in terms of total stress, that is, are not corrected for pore pressures. This test method does not include the procedures necessary to obtain a stress-strain curve beyond the ultimate strength.
1.1.1 This standard replaces and combines the following Standard Test Methods for: D 2664 Triaxial Compressive Strength of Undrained Rock Core Specimens Without Pore Pressure Measurements; D 5407 Elastic Moduli of Undrained Rock Core Specimens in Triaxial Compression Without Pore Pressure Measurements; D 2938 Unconfined Compressive Strength of Intact Rock Core Specimens; and D 3148 Elastic Moduli of Intact Rock Core Specimens in Uniaxial Compression.
1.1.2 The original four standards are now referred to as Methods in this standard as follows: Method A — Triaxial Compressive Strength of Undrained Rock Core Specimens Without Pore Pressure Measurements; Method B — Elastic Moduli of Undrained Rock Core Specimens in Triaxial Compression Without Pore Pressure Measurements; Method C — Unconfined Compressive Strength of Intact Rock Core Specimens; Method D — Elastic Moduli of Intact Rock Core Specimens in Uniaxial Compression; and Option A — Elevated Temperatures.
1.2 For an isotropic material, the relation between the shear and bulk moduli and Young's modulus and Poisson's ratio are:
where: G= shear modulus, K= bulk modulus, E= Young's modulus, and υ= Poisson's ratio.
1.2.1 The engineer...
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
´1
Designation: D7012 – 07
Standard Test Method for
Compressive Strength and Elastic Moduli of Intact Rock
Core Specimens under Varying States of Stress and
1
Temperatures
This standard is issued under the fixed designation D7012; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1
´ NOTE—Adjunct number in Footnote 3 was changed editorially in July 2009
1. Scope 1.1.2 The original four standards are now referred to as
Methods in this standard as follows: Method A — Triaxial
1.1 This test method covers the determination of the
Compressive Strength of Undrained Rock Core Specimens
strength of intact rock core specimens in uniaxial compression
Without Pore Pressure Measurements; Method B — Elastic
and confined compression. The tests provide data in determin-
Moduli of Undrained Rock Core Specimens in Triaxial Com-
ing the strength of rock, namely: the uniaxial strength, shear
pression Without Pore Pressure Measurements; Method C —
strengths at varying pressures and varying temperatures, angle
Unconfined Compressive Strength of Intact Rock Core Speci-
ofinternalfriction,(angleofshearingresistance),andcohesion
mens; Method D — Elastic Moduli of Intact Rock Core
intercept. The test method specifies the apparatus, instrumen-
SpecimensinUniaxialCompression;andOptionA—Elevated
tation, and procedures for determining the stress-axial strain
Temperatures.
andthestress-lateralstraincurves,aswellasYoung’smodulus,
1.2 For an isotropic material, the relation between the shear
E,andPoisson’sratio, y.Itshouldbeobservedthatthismethod
and bulk moduli andYoung’s modulus and Poisson’s ratio are:
makes no provision for pore pressure measurements and
specimens are undrained (platens are not vented). Thus the E
G 5 (1)
strength values determined are in terms of total stress, that is, 2~11y!
are not corrected for pore pressures. This test method does not
E
K 5 (2)
include the procedures necessary to obtain a stress-strain curve
3~1 2 2y!
beyond the ultimate strength.
where:
1.1.1 This standard replaces and combines the following
G = shear modulus,
Standard Test Methods for: D2664 Triaxial Compressive
K = bulk modulus,
Strength of Undrained Rock Core Specimens Without Pore
E = Young’s modulus, and
Pressure Measurements; D5407 Elastic Moduli of Undrained
y = Poisson’s ratio.
Rock Core Specimens in Triaxial Compression Without Pore
1.2.1 The engineering applicability of these equations de-
Pressure Measurements; D2938 Unconfined Compressive
creases with increasing anisotropy of the rock. It is desirable to
Strength of Intact Rock Core Specimens; and D3148 Elastic
conduct tests in the plane of foliation, cleavage or bedding and
Moduli of Intact Rock Core Specimens in Uniaxial Compres-
at right angles to it to determine the degree of anisotropy. It is
sion.
notedthatequationsdevelopedforisotropicmaterialsmaygive
only approximate calculated results if the difference in elastic
1
moduli in two orthogonal directions is greater than 10 % for a
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.
given stress level.
Current edition approved July 1, 2007. Published July 2007. Originally approved
e1
NOTE 1—Elastic moduli measured by sonic methods (Test Method
in 2004. Last previous edition approved in 2004 as D7012–04 . DOI: 10.1520/
D7012-07E01. D2845) may often be employed as preliminary measures of anisotropy.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
´1
D7012 – 07
1.3 This test method given for determining the elastic mation and strength of rock are known to be functions of
constants does not apply to rocks that undergo significant confining pressure. The confined compression test is com-
inelastic strains during the test, such as potash and salt. The monly used to simulate the stress conditions under which most
elastic moduli for such rocks should be determined from underground rock masses exist. The elastic constants are used
unload-reload cycles, that are not covered by this test method. to calculate the stress and deformation in rock structures.
1.4 The values stated in SI units are to be regarded as the 4.3 The deformation and strength properties of rock cores
standard. measured in the laboratory usually do not accurately reflect
1.5 This standard does not purport to address all of the large-scale in situ properties because the latter are strongly
safety concerns, if any, associated with its use. It is the influenc
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D 7012 – 07
Designation:D7012–04
Standard Test Method for
Compressive Strength and Elastic Moduli of Intact Rock
Core Specimens under Varying States of Stress and
1
Temperatures
This standard is issued under the fixed designation D 7012; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1
´ NOTE—Editorial changes were made in January 2007.
—Adjunct number in Footnote 3 was changed editorially in July 2009
1. Scope
1.1 Thistestmethodcoversthedeterminationofthestrengthofintactrockcorespecimensinuniaxialcompressionandconfined
compression. The tests provide data in determining the strength of rock, namely: the uniaxial strength, shear strengths at varying
pressures and varying temperatures, angle of internal friction, (angle of shearing resistance), and cohesion intercept. The test
method specifies the apparatus, instrumentation, and procedures for determining the stress-axial strain and the stress-lateral strain
curves, as well asYoung’s modulus, E, and Poisson’s ratio, y. It should be observed that this method makes no provision for pore
pressure measurements and specimens are undrained (platens are not vented). Thus the strength values determined are in terms of
total stress, that is, are not corrected for pore pressures. This test method does not include the procedures necessary to obtain a
stress-strain curve beyond the ultimate strength.
1.1.1 This standard replaces and combines the following Standard Test Methods for: D 2664 Triaxial Compressive Strength of
Undrained Rock Core Specimens Without Pore Pressure Measurements; D 5407 Elastic Moduli of Undrained Rock Core
Specimens in Triaxial Compression Without Pore Pressure Measurements; D 2938 Unconfined Compressive Strength of Intact
Rock Core Specimens; and D 3148 Elastic Moduli of Intact Rock Core Specimens in Uniaxial Compression.
1.1.2 The original four standards are now referred to as Methods in this standard as follows: MethodA—Triaxial Compressive
Strength of Undrained Rock Core Specimens Without Pore Pressure Measurements; Method B — Elastic Moduli of Undrained
Rock Core Specimens in Triaxial Compression Without Pore Pressure Measurements; Method C — Unconfined Compressive
Strength of Intact Rock Core Specimens; Method D — Elastic Moduli of Intact Rock Core Specimens in Uniaxial Compression;
and Option A — Elevated Temperatures.
1.2 For an isotropic material, the relation between the shear and bulk moduli and Young’s modulus and Poisson’s ratio are:
E
G 5 (1)
2~11y!
E
K 5 (2)
3~1 2 2y!
where:
G = shear modulus,
K = bulk modulus,
E = Young’s modulus, and
y = Poisson’s ratio.
1.2.1 Theengineeringapplicabilityoftheseequationsdecreaseswithincreasinganisotropyoftherock.Itisdesirabletoconduct
tests in the plane of foliation, cleavage or bedding and at right angles to it to determine the degree of anisotropy. It is noted that
equations developed for isotropic materials may give only approximate calculated results if the difference in elastic moduli in two
orthogonal directions is greater than 10 % for a given stress level.
NOTE 1—Elastic moduli measured by sonic methods (Test Method D 2845) may often be employed as preliminary measures of anisotropy.
1.3 This test method given for determining the elastic constants does not apply to rocks that undergo significant inelastic strains
1
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.
Current edition approved . Published February 2004.
e1
Current edition approved July 1, 2007. Published July 2007. Originally approved in 2004. Last previous edition approved in 2004 as D 7012–04 .
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
´1
D7012–07
D7012–04
during the test, such as potash and salt. The elastic moduli for such rocks should be determined from unload-reload cycles, that
are not covered by this test method.
1.4 The values stated in SI units are to be regarded as the standard.
1.5 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
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.