ASTM D5882-07(2013)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D5882 − 07(Reapproved 2013)
Standard Test Method for
Low Strain Impact Integrity Testing of Deep Foundations
This standard is issued under the fixed designation D5882; 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 establish appropriate safety and health practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This test method covers the procedure for determining
the integrity of individual vertical or inclined piles by measur-
NOTE 1—he quality of the result produced by this test method is
ing and analyzing the velocity (required) and force (optional) dependent on the competence of the personnel performing it, and the
suitability of the equipment and facilities used. Agencies that meet the
responseofthepileinducedbyan(handheldhammerorother
criteria of Practice D3740 are generally considered capable of competent
similartype)impactdeviceusuallyappliedaxiallyandperpen-
and objective testing/sampling/ inspection/etc. Users of this test method
dicularlytothepileheadsurface.Thistestmethodisapplicable
are cautioned that compliance with Practice D3740 does not in itself
to long structural elements that function in a manner similar to
assure reliable results. Reliable results depend on many factors; Practice
D3740 provides a means of evaluating some of those factors.
anydeepfoundationunits(suchasdrivenpiles,augeuredpiles,
or drilled shafts), regardless of their method of installation
2. Referenced Documents
provided that they are receptive to low strain impact testing.
1.2 This standard provides minimum requirements for low 2.1 ASTM Standards:
D653Terminology Relating to Soil, Rock, and Contained
strain impact testing of piles. Plans, specifications, and/or
provisions prepared by a qualified engineer, and approved by Fluids
D3740Practice for Minimum Requirements for Agencies
the agency requiring the test(s), may provide additional re-
quirements and procedures as needed to satisfy the objectives Engaged in Testing and/or Inspection of Soil and Rock as
Used in Engineering Design and Construction
of a particular test program.
D6026Practice for Using Significant Digits in Geotechnical
1.3 The text of this standard references notes and footnotes
Data
whichprovideexplanatorymaterial.Thesenotesandfootnotes
(excluding those in tables and figures) shall not be considered
3. Terminology
as requirements of the standard.
3.1 Definitions—Except as defined in 3.2, the terminology
1.4 The values stated in SI units are to be regarded as
used in this test method conforms with Terminology D653.
standard. No other units of measurement are included in this
standard.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 pile integrity, n—the qualitative evaluation of the
1.5 All observed and calculated values shall conform to the
physical dimensions, continuity of a pile, and consistency of
guidelines for significant digits and rounding established in
the pile material.
Practice D6026.
3.2.2 pile impedance, n—the dynamic Young’s modulus of
1.6 The method used to specify how data are collected,
the pile material multiplied by the applicable cross sectional
calculated,orrecordedinthisstandardisnotdirectlyrelatedto
area of the pile and divided by the strain wave speed.
theaccuracytowhichthedatacanbeappliedindesignorother
uses, or both. How one applies the results obtained using this
3.2.3 pulse echo method, n—test in which measurements of
standard is beyond its scope.
the pile head velocity and force (force measurement optional)
are evaluated as a function of time.
1.7 This standard may involve hazardous materials,
operations, and equipment. This standard does not purport to
3.2.4 transient response method, n—test in which the ratio
address all of the safety concerns, if any, associated with its
of velocity transform to force transform (force measurement
use. It is the responsibility of the user of this standard to
required) are evaluated as a function of frequency.
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
RockandisthedirectresponsibilityofSubcommitteeD18.11onDeepFoundations. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2013. Published January 2014. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2000 as D5882 – 07. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D5882-07R13. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5882 − 07 (2013)
4. Significance and Use the fourrier transform of the measured force shall have a
smooth spectrum, without any local peaks.
4.1 Lowstrainimpactintegritytestingprovidesacceleration
5.2.3 Placement of Transducers—Themotionsensorshould
or velocity and force (optional) data on slender structural
beplacedatornearthepileheadusingasuitable,ortemporary,
elements(thatis,structuralcolumns,drivenconcretepiles,cast
thinlayerofbondingmaterial(thatis,wax,vaseline,puttyetc.)
in place concrete piles, concrete filled steel pipe piles, timber
so that it is assured that it correctly measures the axial pile
piles, etc.). The method works best on solid concrete sections,
motion (transducer axis of sensitivity aligned with the pile
and has limited application to unfilled steel pipe piles, H piles,
axis). The motion sensor is placed generally near the center of
orsteelsheetpiles.Thesedataassistevaluationofpileintegrity
the pile. Additional locations should be considered for piles
and pile physical dimensions (that is, cross-sectional area,
with diameters greater than 500 mm. The low strain impact
length), continuity, and consistency of the pile material, al-
shouldbeappliedtothepileheadwithinadistanceof300mm
though evaluation is approximate and not exact. This test
from the motion sensor. If the pile head is not accessible, as
method will not give information regarding the pile bearing
when already integral with the structure, the sensor(s) may be
capacity.
attached to the side of the pile shaft.
4.1.1 Methods of Testing:
5.3 Signal Transmission—Thesignalsfromthesensorsshall
4.1.1.1 Pulse Echo Method (PEM)—Thepileheadmotionis
be conveyed to the apparatus for recording, reducing, and
measuredasafunctionoftime.Thetimedomainrecordisthen
displaying the data, see 5.4, by a low noise shielded cable or
evaluated for pile integrity.
equivalent.
4.1.1.2 Transient Response Method (TRM)—The pile head
motionandforce(measuredwithaninstrumentedhammer)are 5.4 Apparatus for Recording, Reducing and Displaying
measured as a function of time.The data are evaluated usually Data:
in the frequency domain. 5.4.1 General—The signals from the motion and force
(optional) sensors, see 5.2, shall be conveyed to an apparatus
5. Apparatus for recording, reducing, and displaying data as a function of
time. The apparatus shall include a graphic display of velocity
5.1 Apparatus for Applying Impact:
(Fig. 1) and force (optional), and a data storage capability for
5.1.1 Impact Force Application—The impact may be deliv-
retrieving records for further analysis. . The velocity display
eredbyanydevice(forexample,ahandheldhammer)thatwill
can be referenced either to the initial rise, as shown, or to the
produce an input force pulse of generally less than 1 ms
firstpeak.Theapparatusshouldbecapableofaveragingdataof
durationandshouldnotcauseanylocalpiledamageduetothe
several blows to reinforce the repetitive information from soil
impact. A hammer with a very hard plastic tip can induce a
and pile effects while reducing random noise effects. The
short input force pulse without causing local pile damage. The
apparatus shall be able to apply increasing intensity amplifi-
impact should be applied axially to the pile (normally on the
cation of the motion signal with time after the impact to
pile head).
enhance the interpretation of the measured motions that are
5.2 Apparatus for Obtaining Measurements: reducedbysoilandpilematerialdamping.Theapparatusmust
have filtering capability with variable frequency limits for
5.2.1 Velocity Measurement—Obtain velocity data from in-
eliminating high frequency, or low frequency signal
tegration of signals from (one or more) accelerometers, pro-
components, or both. The apparatus shall be capable of
vided the acceleration signal(s) can be integrated to velocity in
transferring all data to a permanent storage medium. The
the apparatus for reducing data. The accelerometer(s) should
be placed at (or near) the pile head and shall have their
sensitive axis parallel with the pile axis. Accelerometers shall
belineartoatleast50 g.EitherA/CorD/Caccelerometerscan
be used. If A/C devices are used, the time constant shall be
greater than 0.5 s and the resonant frequency shall be at least
30000 Hz. If D/C devices are used, they shall have frequency
response up to 5000 Hz with less than−3 dB reduction of
content. Alternatively, velocity or displacement transducers
may be used to obtain velocity data, provided they are
equivalent in performance to the specified accelerometers.
Calibrate the transducer to an accuracy of 5% throughout the
applicable measurement range. If damage is suspected during
use, recalibrate or replace the accelerometer.
5.2.2 Force Measurement (optional)—The impact device
shallbecapableofmeasuringtheimpactforceasafunctionof
time. The hammer may have a force load cell between the tip
and hammer body. Alternatively, the hammer may have an
FIG. 1 Typical Velocity Traces for the Pulse Echo Method Gener-
accelerometer attached and the measured acceleration may be
ated by the Apparatus for Obtaining Dynamic Measurements
converted to force using the hammer mass. The force calibra-
(note the orientation of the input pulse is shown as positive in
tion shall be within 5%. The hammer must be tuned such that this standard; orientation could also be shown negative)
D5882 − 07 (2013)
apparatus shall allow for a permanent graphical output of the 5.4.4 Display Apparatus—Ensure that the signals from the
records. A typical schematic arrangement for this apparatus is transducersspecifiedin5.2.1and5.2.2aredisplayedbymeans
illustrated in Fig. 2. of an apparatus, such as an LCD graphic display, such that the
velocity and force (optional) can be observed as a function of
NOTE2—Itisrecognizedthatthevelocitysignalmaybedrawnineither
time for each hammer blow. This apparatus may receive the
downwardorupwardpositiveamplitudes.Thedepthscalemaybealigned
signals after they have been processed by the apparatus for
either at the start of the rise (as shown) or at the initial peak. It is
recommended that information be included in the plot showing the
reducingthedata.Theapparatusshalldisplaythedigitizeddata
magnification function with time.
of the impact event or upon recall by the user of the digitally
5.4.2 Recording Apparatus—Analog signals from the mo- storedevent.Adjusttheapparatustoreproduceasignalhaving
tionsensormustbedirectlydigitizedusingananalogtodigital adurationgreaterthan2L/cplus5milliseconds,whereListhe
converter with at least 12 bit resolution (16 bit or higher pile length and c is the material wave speed.
resolution is preferred)such that signal components having a
low pass cut-off frequency of 5000 Hz (−3dB) are retained.
6. Procedure
When digitizing, the sample frequency, therefore, shall be at
6.1 General—Record applicable project information into
least 25000 Hz each for the motion sensor and the optional
the apparatus when appropriate (Section 7). The appropriate
instrumented hammer, if used.The uniformity and accuracy of
motion sensor (see 5.2) shall be attached to or pressed against
the digital sampling frequency is critical; the clock jitter
the pile head. Record the measurements from several impacts.
(sampling frequency accuracy) must be within 0.01%.Analog
Averagethesuitablerecordsofatleastthreeimpactsandapply
data acquisition systems are specifically prohibited. Attached
necessary amplification to the averaged record. The records
to every digitized event should be identifying information
from the individual impacts or the averaged record, or both,
names and descriptions, signal processing enhancement
should then be stored (see 5.4.2). The averaged, amplified
parameters, and date and time stamps. The digital record shall
record then can be evaluated for integrity.
be permanently stored.
5.4.3 Apparatus for Reducing Data—The apparatus for 6.2 Preparation—For cast-in-place concrete piles or con-
reducing signals from the transducers shall be a digital com- crete filled pipe piles, perform the integrity testing no sooner
puter or microprocessor capable of at least the following than 7 days after casting or after concrete strength achieves at
functions: least 75% of its design strength, whichever occurs earlier.
5.4.3.1 Velocity Data—If accelerometers are used (see Ensure that the pile head surface is accessible, above water,
5.2.2), the apparatus shall provide signal conditioning and and clean of loose concrete, soil or other foreign materials
integrate acceleration to obtain velocity. The apparatus shall resulting from construction. If the pile head is contaminated,
balance the velocity signal to zero between impact events. remove a sufficient pile section to reach sound concrete.
5.4.3.2 Force Measurements—The apparatus shall provide Because proper pile top preparation is critical to the successful
applicationofthismethod,ifnecessary,preparesmallareasby
signal conditioning and amplification, for the force measure-
ments. The force output shall be balanced to zero between a hand grinder to provide a smooth surface for motion sensor
impact events. attachment and impact.Attach the motion sensor firmly to pile
5.4.3.3 Signal Conditioning—The force and velocity data (i.e. solid contact) at selected locations away from the edge of
shall have equal frequency response curves to avoid relative the pile head. For piles with diameters larger than 500 mm,
phase shifts and amplitude differences. attach the accelerometer at a minimum of three locations so
FIG. 2 Schematic Diagram of Apparatus for Integrity Testing
D5882 − 07 (2013)
thatanintegrityevaluationnearthepileheadmaybemadefor sufficient information for integrity evaluation. Alternately, the
each localized section of pile. Position the apparatus for pile head force can be measu
...