ASTM D5079-90(1996)
(Practice)Standard Practices for Preserving and Transporting Rock Core Samples
Standard Practices for Preserving and Transporting Rock Core Samples
SCOPE
1.1 These practices cover the preservation, transportation, storage, cataloging, retrieval, and post-test disposition of rock core samples obtained for testing purposes and geologic study.
1.2 These practices apply to both hard and soft rock, but exclude ice and permafrost.
1.3 These practices do not apply to those situations in which changes in volatile gas components, contamination of the pore fluids, or mechanical stress relaxation affect the intended use for the core.
1.4 This practice offers a set of instruction for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgement. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word "Standard" in the title of this document means only that the document has been approved through the ASTM consensus process.
1.5 This standard does not purport to address the safety problems 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.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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.
Designation: D 5079 – 90 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Practices for
Preserving and Transporting Rock Core Samples
This standard is issued under the fixed designation D 5079; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope dated that soil sampling procedures must be employed to
obtain intact pieces of core.
1.1 These practices cover the preservation, transportation,
3.1.4 special care—fluid sensitive samples and those which
storage, cataloging, retrieval, and post-test disposition of rock
must later be subjected to testing. Requirements for this level
core samples obtained for testing purposes and geologic study.
of protection include those prescribed for routine care.
1.2 These practices apply to both hard and soft rock, but
exclude ice and permafrost.
4. Significance and Use
1.3 These practices do not apply to those situations in which
4.1 The geologic characteristics and the intended use of the
changes in volatile gas components, contamination of the pore
rock core samples determine the extent and type of preserva-
fluids, or mechanical stress relaxation affect the intended use
tion required. If engineering properties are to be determined for
for the core.
the core, it must be handled and preserved in such a way that
1.4 This standard does not purport to address the safety
the measured properties are not significantly influenced by
problems associated with its use. It is the responsibility of the
mechanical damage, changes in chemistry, and environmental
user of this standard to establish appropriate safety and health
conditions of moisture and temperature, from the time that the
practices and determine the applicability of regulatory limita-
core is recovered from the core drill until testing is performed.
tions prior to use.
Drill core is also the sample record for the subsurface geology
2. Referenced Documents at the borehole location, and as such must be preserved for
some period of timed, in some cases indefinitely, for future
2.1 ASTM Standards:
geologic study.
D 420 Practice for Investigating and Sampling Soil and
4.2 These practices present a selection of curatorial require-
Rock for Engineering Purposes
ments which apply to the majority of projects. The require-
D 2113 Practice for Diamond Core Drilling for Site Inves-
ments are given for a variety of rock types and project types
tigation
ranging from small to large and from noncritical to critical.
D 4220 Practice for Preserving and Transporting Soil
Noncritical projects are those in which failure of an element or
Samples
the structure would result in negligible risk of injury and
2.2 API Standard:
property loss, while there is great risk to property and life after
API RP-40 Recommended Practice for Core Analysis Pro-
failure of critical structures and projects. Guidance is given for
cedure
the selection of those specific requirements which should be
3. Terminology
followed for a given project.
3.1 Definitions of Terms Specific to This Standard:
5. Guide for Implementation
3.1.1 critical care—samples which are fragile or fluid or
5.1 A qualified person shall be assigned to have curatorial
temperature sensitive. This protection level includes the re-
management responsibility for a given project. This person
quirements prescribed for routine and special care.
shall be technically competent in the management of rock core
3.1.2 routine care—non-sensitive, non-fragile samples for
samples and shall have a knowledge of the various end uses for
which only general visual identification is necessary, and
the cores and their associated preservation requirements. This
samples which will not change or deteriorate before laboratory
responsible person shall have the authority to implement the
testing.
requirements selected from these practices. In some cases, he
3.1.3 soil-like care—materials which are so poorly consoli-
or she may also have to decide between competing uses for the
same core.
These practices are under the jurisdiction of ASTM Committee D-18 on Soil
5.2 The responsible person shall select from Sections 6-11
and Rock and are the direct responsibility of Subcommittee D18.12 on Rock
those requirements and procedures that should be applied for
Mechanics.
the core from a particular project. The curatorial manager shall
Current edition approved June 29, 1990. Published August 1990.
Annual Book of ASTM Standards, Vol 04.08. then see that these procedures are implemented, and also see
Available from American Petroleum Institute, 1220 L Street, Washington, DC
that the records specified in Section 12 are kept.
20005.
D 5079
5.3 The following factors should be considered when select-
ing the curatorial requirements from Sections 6-11:
5.3.1 Project requirements for use of the core range from
simple ones, in which the only need is to identify and locate the
various lithologic units, to complex and critical ones in which
detailed property testing of the core is required for engineering
design. Priorities for multiple uses or different types of tests
must sometimes be established when available core lengths are
limited and when one use or test precludes another. For
example, splitting a core for detailed geologic study prevents
later strength testing, which requires an intact core.
5.3.2 Mechanical property tests for structural design pur-
poses should be performed on a core in its natural moisture
state, particularly if the rocks are argillaceous. Irreversible
changes occur when such rocks are allowed to dry out, often
resulting in invalid design data. The initial moisture content of
such a core should therefore be preserved.
5.3.3 Freezing of pore water in the core may reduce the
strength of the rock. The high temperature associated with
unventilated storage sheds in summer, and temperatures alter-
nating between hot and cold, may cause moisture migration
from the core and weakening of the rock due to differential
thermal expansion and contraction between grains. Such tem-
perature extremes should therefore be avoided, particularly for
weak sedimentary rock types.
5.3.4 A weak rock core may be broken or further weakened
by careless handling, such as dropping a core box, or by
mechanical vibration and shock during transportation. Break-
NOTE 1—Numbers refer to corresponding sections of this practice.
ing of the core reduces sample lengths available for testing.
FIG. 1 Flow Chart for Core Handling, Use, and Storage Activities
Weakening caused by such mechanical stressing may lower
measured strength parameters and may affect other properties.
6.2 Controlled Humidity Room.
5.3.5 The required preservation time may vary from as short
6.3 Core Boxes—See 7.6.1.
as three months to several years, and sometimes core may need
6.4 Vinylidene Chloride Plastic Film, Aluminum Foil, Plas-
to be stored indefinitely. A core taken simply to identify the
tic Microcrystalline Wax, for sealing in moisture content of
bedrock lithology beneath a small structure may be needed for
cores.
a few months only. For large and critical structures, it may be
6.5 Polyethylene Layflat Plastic Tubing.
necessary to retain the core for many years as re-examination
6.6 Poly(vinyl chloride) Tubing.
and testing may be required at some later time for additional
6.7 Sawdust, Rubber, Polystyrene, or material of similar
geologic study or re-evaluation of property data. Some states
resiliency to cushion the core.
have regulations governing the disposition and storage of core
6.8 Miscellaneous Equipment, such as adhesive tape and
obtained within the state.
waterproof felt-tip markers.
5.4 Fig. 1 is a flow chart that shows the various core
handling, use, and storage activities and the corresponding
7. Requirements and Procedures at the Drilling Site
section numbers in these practices. Note that four care or
7.1 Sample Recovery:
protection levels are defined in Section 3 to account for the
7.1.1 Accomplish sample recovery in accordance with Prac-
great variety of rock sensitivities and core uses encountered in
tice D 2113 or API RP-40.
practice.
7.1.2 Whichever approved drilling method is used, remove
5.5 The person assigned curatorial management responsibil-
the samples from the core barrel with a minimum of distur-
ity should study the flow chart in Fig. 1 as it relates to the
bance.
designated Sections 6-11 in these practices. Note in particular,
7.2 Handling:
that a selection of the required protection must be made in 7.5,
7.2.1 Each borehole shall be given full-time attention by a
where four levels of protection are specified, namely routine
qualified inspector constantly available for observing, direct-
care, special care, critical care, and soil-like care.
ing, photographing, and field logging. The inspector shall not
5.6 Special attention is also directed to records requirements
perform simultaneously the same duties for more than one
in Section 12, that document the history of the core handling,
boring unless the borings are close enough to each other so that
preservation, and storage.
the entire inspection process can be done for each boring.
6. Apparatus
7.2.2 For relatively solid pieces of core that will not be
6.1 Camera, for taking photographs of cores for logging. adversely affected, the inspector shall use a marker, such as a
D 5079
felt-tip, to orient each piece so that later users will always be lithologic contact depths, types and locations of protection
able to distinguish top from bottom. Acceptable formats are a applied to samples, and any facts that would otherwise be
continuous line with arrows or parallel solid and dashed lines unknown to whomever may complete a more detailed log at a
with the dashed line always on the same side of the solid line. later time. It is desirable that detailed logs be completed by the
The direction convention shall be recorded in the log book. same inspector who does the field logging. It is advisable for
Locations of known depths should be marked directly on the the inspector immediately to make notations on the depths at
core when the orientation marks are drawn. which, in his judgment, any core losses occurred. Sometimes it
7.3 Core Photography: is possible later to fill in gaps in the initial log by interpreta-
7.3.1 Perform core photography on all core samples with a tions from wireline logs.
camera of 35 mm (minimum) format using color film to record 7.4.2 The inspector is to complete a detailed log on the drill
, , ,
4 5 6 7
permanently the unaltered appearance of the rock. The film site (see the literature ) in cases where the core is likely
selected should be color balanced for the available lighting to deteriorate or otherwise change before being examined
(daylight, flash, incandescent, or florescent), or an appropriate again.
filter should be placed on the camera to compensate for the 7.4.3 For fragile core that must be immediately protected by
difference. The core should be cleaned prior to any photogra- wrapping and sealing, preliminary logging should take place in
phy. the field, but application of protective measures are to take
7.3.2 A commercially available color strip chart should be precedence over time-consuming detailed logging.
included in the photo frame to serve as a reference to check the
NOTE 1—It is permissible later to make changes in detailed logs when
accuracy of the photographic reproduction of the rock core
laboratory analysis indicates original misidentification of rock type or
colors.
other geologic features.
7.3.3 For rock placed in core boxes, take one photo of each
7.5 Sample Protection—Four levels of sample protection
box once it is filled to capacity. Include the inside of the box lid
are covered (see Section 3): routine care, special care, critical
with appropriate identification data and a clearly visible length
care, and soil-like care. The level of protection chosen will
scale laid along one edge of the box so that it also shows in the
depend on the geologic character of the rock and the intended
photo.
use for the core.
7.3.4 Where very long, intact cores are being preserved in
7.5.1 Routine care (see Fig. 2):
single plastic tubes, make detail-revealing close-ups of each
7.5.1.1 For rock cored in 5 to 10-ft. runs, samples are
core interval in addition to a single photo showing the complete
sufficiently protected if placed in structurally sound core boxes.
core.
Enclosing the core in a loose-fitting polyethylene sleeve
7.3.5 Take photographs before the core is obscured by
(layflat tubing) prior to placing the core in the core box is
protective sealants and wraps, and before any deterioration
recommended.
begins in particularly fragile or sensitive rock types.
7.5.1.2 Where very long solid cores have been recovered
7.3.6 For a boxed core that is not particularly sensitive and
and need to be preserved intact, place each core in a reasonably
for which maintenance of in-situ moisture content is not
stiff tube (poly(vinyl chloride) (PVC) tubing is recommended)
important, two photos should be made: one with the core in a
of equal or slightly greater length and secure both ends to
surface dry condition and one with the core in a wet condition
prevent slippage. The inside diameter of the tube should be
to bring out optical properties that would not otherwise be
slightly greater than the core diameter; the wall thickness of the
apparent.
tube must be sufficient to provide the rigidity to prevent core
7.3.7 This procedure may require photography both in the
breakage due to bending.
field and then later in the storage facility, but it must be
7.5.2 Special Care:
completed before any test core removal and before damage
7.5.2.1 The moisture state of some rocks, and even the
from mishandling has a chance to occur.
moisture-state history of rocks such as shales, affects their
7.3.8 Where it is impossible for a photo to show identifica-
properties. If tests are to be performed on the core, and if it is
tion data marked directly on the sample or its container, then
possible that a change in the moisture state may influence the
mount appropriately marked placards so as to be included in
test results, then the core must be sealed to prevent changes in
the frame.
the moisture state until the time of testing. This same procedure
7.3.9 Organize the photographs and mount in a folder for
also applies to other samples where it is important to maintain
easy access and pr
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.