ASTM D4553-18

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4553 − 18
Standard Test Method for
Determining In Situ Creep Characteristics of Rock
This standard is issued under the fixed designation D4553; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* dures used do not consider material variation, purpose for
obtaining the data, special purpose studies, or any consider-
1.1 This test method covers the preparation, equipment, test
ations for the user’s objectives; and it is common practice to
procedure, and data documentation for determining in situ
increase or reduce significant digits of reported data to be
creep characteristics of a rock mass using a rigid plate loading
commensuratewiththeseconsiderations.Itisbeyondthescope
method.
of these test methods to consider significant digits used in
1.2 This test method is designed to be conducted in an adit
analysis methods for engineering data.
or small underground chamber; however, with suitable
1.7 This standard does not purport to address all of the
modifications, this test could be conducted at the surface.
safety concerns, if any, associated with its use. It is the
1.3 Thetestisusuallyconductedparallelorperpendicularto
responsibility of the user of this standard to establish appro-
the anticipated axis of thrust, as dictated by the design load or
priate safety, health, and environmental practices and deter-
other orientations, based upon the application.
mine the applicability of regulatory limitations prior to use.
For specific precaution statements, see Section 8.
1.4 Flexible plate apparatus can be used if the anticipated
1.8 This international standard was developed in accor-
creep displacement is within the tolerance of the travel of the
dance with internationally recognized principles on standard-
flat jacks.
ization established in the Decision on Principles for the
1.5 Units—The values stated in inch-pound units are to be
Development of International Standards, Guides and Recom-
regarded as standard. The values given in parentheses are
mendations issued by the World Trade Organization Technical
mathematical conversions to SI units that are provided for
Barriers to Trade (TBT) Committee.
informationonlyandarenotconsideredstandard.Reportingof
testresultsinunitsotherthaninch-poundshallnotberegarded
2. Referenced Documents
as nonconformance with this standard.
2.1 ASTM Standards:
1.5.1 The gravitational system of inch-pound units is used
D653Terminology Relating to Soil, Rock, and Contained
when dealing with inch-pound units. In the system, the pound
Fluids
(lbf) represents a unit of force (weight), while the units for
D3740Practice for Minimum Requirements for Agencies
mass is slugs. The slug unit is not given, unless dynamic (F =
Engaged in Testing and/or Inspection of Soil and Rock as
ma) calculations are involved.
Used in Engineering Design and Construction
1.6 All observed and calculated values shall conform to the
D4394Test Method for Determining In Situ Modulus of
guidelines for significant digits and rounding established in
Deformation of Rock Mass Using Rigid Plate Loading
Practice D6026, unless superseded by this test method.
Method
1.6.1 For purposes of comparing a measured or calculated
D4403Practice for Extensometers Used in Rock
value(s) with specified limits, the measured or calculated
D4879Guide for Geotechnical Mapping of Large Under-
value(s) shall be rounded to the nearest decimal of significant
ground Openings in Rock (Withdrawn 2017)
digits in the specified limit.
D6026Practice for Using Significant Digits in Geotechnical
1.6.2 Theproceduresusedtospecifyhowdataarecollected/
Data
recorded and calculated in the standard are regarded as the
3. Terminology
industry standard. In addition, they are representative of the
significant digits that generally should be retained. The proce-
3.1 Definitions:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Rock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved July 1, 2018. Published August 2018. Originally the ASTM website.
approved in 1985. Last previous edition approved in 2008 as D4553–08, which The last approved version of this historical standard is referenced on
was withdrawn January 2017 and reinstated July 2018. DOI: 10.1520/D4553-18. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4553 − 18
3.1.1 Fordefinitionsofcommontechnicaltermsusedinthis rigid as feasible, the rock face is smoothed, and a thin,
standard, refer to Terminology D653. high-modulus material is used for the pad, the error in the
measured displacements will be minimal.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 creep—a time-dependent displacement of a plate
6.2 The rock under the loaded area is generally not
pushed into the surface of the rock by a constant normal load.
homogeneous, as assumed in theory. The rock will respond to
It is not directly related with laboratory creep data because of
theloadaccordingtoitslocaldeformationalcharacteristicsand
the nonuniformity of stress within the rock mass underneath
orientation of discontinuities. The use of the average plate
the plate.
displacement will mitigate this problem. If this creep test is
performedimmediatelyafteraplateloadingtest—TestMethod
3.2.2 displacement—movementoftherigidplate,groutpad,
D4394, for instance, the results of the creep test will be
or rock in response to and in the same direction as the applied
different than if it had been performed on virgin rock.
load.
3.2.3 load—total force acting on the rock face.
7. Apparatus
3.2.4 rigid plate—platewithadeflectionoflessthan0.0005
7.1 Surface Preparation Equipment—Test site preparation
in. (0.0127 mm) from the center to the edge of the plate when
equipment shall include an assortment of excavation tools,
maximum load is applied.
such as drills and chipping hammers. Blasting shall not be
4. Summary of Test Method allowed during a preparation of the test site.
4.1 Areas on two opposing faces of a test adit underground
7.2 Instrumentation:
chamber are flattened and smoothed.
7.2.1 Displacement Measuring Equipment—For displace-
ment measurements, dial gauges or linear variable differential
4.2 A grout pad and rigid metal plate are installed against
transformers (LVDTs) are generally used. An accuracy of at
eachfaceandahydraulicloadingsystemisplacedbetweenthe
least 60.0001 in. (0.0025 mm), including the error of the
rigid plates.
readout equipment, and a sensitivity of at least 0.00005 in.
4.3 The two faces are rapidly loaded to the desired creep
(0.0013 mm) is recommended. Errors in excess of 0.0004 in.
load,withoutshock,theloadmaintained,andthedisplacement
(0.01mm)caninvalidatetestresultswhenthemodulusofrock
of the plate measured as a function of time.
6 4
mass exceeds 5×10 psi (3.5×10 MPa).
7.2.2 Load Cell—A load cell is recommended to measure
5. Significance and Use
the load on the bearing plate. An accuracy of 61000 lbf (4.4
5.1 Results of this test method are used to predict time-
kN) or 65 % of maximum test load, including errors intro-
dependent deformation characteristics of a rock mass resulting
duced by the readout system, and a sensitivity of at least 500
from loading. It is a test that may be required depending on
lbf (2.2 kN) are recommended. Long-term stability of the
rock type or anticipated loads, or both.
instrumentation system shall be verified throughout the test.
5.2 This test method may be useful in structural design
7.3 Loading Equipment:
analysis where loading is applied over an extensive period.
7.3.1 Hydraulic Ram or Flat Jacks—This equipment, ca-
5.3 This test method is normally performed at ambient
pable of applying and maintaining desired pressures to within
temperature in the field, but equipment can be modified or
63 %, is usually used to apply the load.Aspherical bearing of
substituted for operations at other temperatures.
suitable capacity shall be coupled to one of the bearing plates.
5.4 Results of this test method may be useful in verifying
If a hydraulic ram is used, the load shall be corrected to
laboratory creep data and structural mathematical modeling accountfortheeffectsoframfriction.Ifflatjacksareused,the
analyses.
jacksshallnotbeexpandedbeyondathicknessequalto3%of
the diameter of a metal jack and care shall be taken that the
5.5 Creep characteristics are determined under a nonuni-
jacks do not operate at the upper end of their range.
form state of stress within the rock mass underneath the plate.
7.3.2 The loading equipment includes a device for applying
5.6 If during a field investigation, time-dependent charac-
the load and the reaction members, usually thick-walled
teristics are detected, then an in situ creep test shall be
aluminum or steel pipes, to transmit the load.
performed.
7.3.3 Load Maintaining Equipment—Equipment such as a
NOTE 1—The quality of the result produced by this standard is
servo-control system or air over hydraulic oil is required.
dependent on the competence of the personnel performing it, and the
suitability of the equipment and facilities used. Agencies that meet the
7.3.4 Bearing Pads—Thebearingpadsshallhaveamodulus
6 4
criteria of Practice D3740 are generally considered capable of competent
of elasticity of around 4×10 psi (3×10 MPa) and shall be
and objective testing/sampling/inspection/etc. Users of this standard are
capable of conforming to the rock surface and bearing plate.
cautioned that compliance with Practice D3740 does not in itself assure
High early strength grout or molten sulfur bearing pads are
reliable results. Reliable results depend on many factors; Practice D3740
provides a means of evaluating some of those factors. recommended.
7.3.5 Bearing Plates—The bearing plates shall approximate
6. Interferences
a rigid die as closely as practical.Abearing plate that has been
6.1 Acompletely inflexible plate used to load the rock face foundsatisfactoryisshowninFig.1.Althoughtheexactdesign
is difficult to construct. However, if the plate is constructed as and materials may differ, the stiffness of the bearing plate shall
D4553 − 18
FIG. 1 Rigid Bearing Plate for 12 in. (30.5 cm) Diameter In Situ Creep Test
be the minimum stiffness necessary to not produce measurable approximatelysixtimestheplatediameter;recommendedplate
1 1
deflection of the plate under maximum load. diameter is commonly 1 ⁄2 to 3 ⁄4 ft (0.5 to 1 m). Other sizes
are used depending upon site specifics. A map of the adit and
8. Safety Hazards
test site shall be prepared in accordance with Guide D4879.
8.1 Enforce safety by applicable safety standards.
9.3 The effects of anisotropy should be investigated by
appropriately oriented tests; for example, parallel and perpen-
8.2 Pressure lines should be bled of air to preclude violent
dicular to the bedding of a sedimentary sequence, or parallel
failure of the pressure system.
and perpendicular to the long axes of columns in a basalt flow.
8.3 Total displacement should not exceed the expansion
9.4 Tests shall be performed at a site not affected by
capabilitiesoftheflatjacks;normallythisisapproximately3%
of the diameter of a metal jack. structural changes resulting from excavations of the adit. The
zone of rock that contributes to the measured displacement
9. In Situ Conditions
during the plate loading depends on the diameter of the plate
NOTE 2—The guidelines presented in this section are the domain of the
and the applied load. Larger plates and higher loads measure
agencyororganizationrequestingthetestingandareintendedtofacilitate
theresponseofrockfurtherawayfromthetestadit.Thus,ifthe
definition of the scope and development of site-specific requirements for
rockaroundtheaditisdamagedbytheexcavationprocess,and
the testing program as a whole.
thedeformational/creeppropertiesofthedamagedzonearethe
9.1 Test each structurally distinctive zone of rock mass
primary objective of the test program, small-diameter plate
selectingareasthataregeologicallyrepresentativeofthemass.
tests on typically excavated surfaces are adequate.
Test those portions of the rock mass with features such as
9.5 Siteconditionsmaydictatethatsitepreparationandpad
faults, fracture zones, cavities, inclusions, and the like to
construction be performed immediately after excavation.
evaluatetheireffects.Designthetestingprogramsothateffects
oflocalgeologycanbeclearlydistinguishedandtheimpactof
excavation minimized. 10. Procedure
9.2 The size of the bearing plate will be determined by the 10.1 Verifythecomplianceofequipmentandapparatuswith
local geology, pressures to be applied, and the size of the adit theperformancespecificationsinSection7.Ifrequirementsare
to be performed. These parameters should be considered prior not stated, the manufacturer’s specifications for the equipment
to excavation of the adit. Acceptable adit dimensions are may be appropriate as a guide, however, care should be taken
D4553 − 18
for sufficient performance. Performance verification is gener- very small charges is advised to remove the unwanted/residual
ally done by calibrating the equipment and measurement materials. In weaker materials, coarse grinding or cutting
system. Accomplish calibration and documentation in accor- devices may be used.
dance with the quality assurance procedures in Annex A1.
10.4.2 Size—The prepared rock surface shall extend at least
one-half the diameter of the bearing plate beyond the edge of
10.2 Ensure that the test results are defensible and traceable
the plate.
by following at least the minimum guidelines for personnel
10.4.3 Rock Quality—To the extent practicable, prepare the
qualifications, calibrations, test setup, test procedure, equip-
bearing surface in sound rock. Remove loose and broken rock
ment performance and verification, and vetting of test data are
from the excavation. Deeper breaks may be detected by a dull
followed in Annex A1.
hollow sound when the rock surface is struck with a hammer;
10.3 Conduct the test across a “diameter” or chord of the
remove such material.
adit with the two test surfaces nearly parallel and in planes
10.4.
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