More D The method works best on solid concrete sections, and has limited application to unfilled steel pipe piles, H piles, or steel sheet piles. These data assist evaluation of the pile cross-sectional area and length, the pile integrity and continuity, as well as consistency of the pile material, although evaluation is approximate. This test method will not provide information regarding the pile bearing capacity. It is generally helpful to consider the soil profile, construction method and site records when evaluating data obtained by this method.
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A number in parentheses indicates the year of last reapproval. This test method is applicableto long structural elements that function in a manner similar toany deep foundation units such as driven piles, augeured piles,or drilled shafts , regardless of their method of installationprovided that they are receptive to low strain impact testing.
These notes and footnotes excluding those in tables and figures shall not be consideredas requirements of the standard. No other units of measurement are included in thisstandard. How one applies the results obtained using thisstandard is beyond its scope. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.
NOTE 1—he quality of the result produced by this test method isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Users of this test methodare cautioned that compliance with Practice D does not in itselfassure reliable results. Reliable results depend on many factors; PracticeD provides a means of evaluating some of those factors.
Referenced Documents2. Current edition approved Nov. Published January Originallyapproved in Last previous edition approved in as D — United States Significance and Use4.
The method works best on solid concrete sections,and has limited application to unfilled steel pipe piles, H piles,or steel sheet piles. These data assist evaluation of pile integrityand pile physical dimensions that is, cross-sectional area,length , continuity, and consistency of the pile material, al-though evaluation is approximate and not exact.
This testmethod will not give information regarding the pile bearingcapacity. The time domain record is thenevaluated for pile integrity. The data are evaluated usuallyin the frequency domain. A hammer with a very hard plastic tip can induce ashort input force pulse without causing local pile damage. Theimpact should be applied axially to the pile normally on thepile head. The accelerometer s shouldbe placed at or near the pile head and shall have theirsensitive axis parallel with the pile axis.
Accelerometers shallbe linear to at least 50 g. Alternatively, velocity or displacement transducersmay be used to obtain velocity data, provided they areequivalent in performance to the specified accelerometers. If damage is suspected duringuse, recalibrate or replace the accelerometer. The hammer may have a force load cell between the tipand hammer body. Alternatively, the hammer may have anaccelerometer attached and the measured acceleration may beconverted to force using the hammer mass.
The hammer must be tuned such thatthe fourrier transform of the measured force shall have asmooth spectrum, without any local peaks.
The motion sensor is placed generally near the center ofthe pile. Additional locations should be considered for pileswith diameters greater than mm. The low strain impactshould be applied to the pile head within a distance of mmfrom the motion sensor.
If the pile head is not accessible, aswhen already integral with the structure, the sensor s may beattached to the side of the pile shaft. The apparatus shall include a graphic display of velocity Fig. The velocity displaycan be referenced either to the initial rise, as shown, or to thefirst peak. The apparatus should be capable of averaging data ofseveral blows to reinforce the repetitive information from soiland pile effects while reducing random noise effects.
Theapparatus shall be able to apply increasing intensity amplifi-cation of the motion signal with time after the impact toenhance the interpretation of the measured motions that arereduced by soil and pile material damping. The apparatus musthave filtering capability with variable frequency limits foreliminating high frequency, or low frequency signalcomponents, or both.
The apparatus shall be capable oftransferring all data to a permanent storage medium. A typical schematic arrangement for this apparatus isillustrated in Fig. NOTE 2—It is recognized that the velocity signal may be drawn in eitherdownward or upward positive amplitudes. The depth scale may be alignedeither at the start of the rise as shown or at the initial peak. It isrecommended that information be included in the plot showing themagnification function with time.
When digitizing, the sample frequency, therefore, shall be atleast 25 Hz each for the motion sensor and the optionalinstrumented hammer, if used. The uniformity and accuracy ofthe digital sampling frequency is critical; the clock jitter sampling frequency accuracy must be within 0. Analogdata acquisition systems are specifically prohibited. Attachedto every digitized event should be identifying informationnames and descriptions, signal processing enhancementparameters, and date and time stamps.
The digital record shallbe permanently stored. The apparatus shallbalance the velocity signal to zero between impact events. The force output shall be balanced to zero betweenimpact events. This apparatus may receive thesignals after they have been processed by the apparatus forreducing the data. The apparatus shall display the digitized dataof the impact event or upon recall by the user of the digitallystored event.
The appropriatemotion sensor see 5. Record the measurements from several impacts. Average the suitable records of at least three impacts and applynecessary amplification to the averaged record.
The recordsfrom the individual impacts or the averaged record, or both,should then be stored see 5. The averaged, amplifiedrecord then can be evaluated for integrity. Ensure that the pile head surface is accessible, above water,and clean of loose concrete, soil or other foreign materialsresulting from construction. If the pile head is contaminated,remove a sufficient pile section to reach sound concrete. Because proper pile top preparation is critical to the successfulapplication of this method, if necessary, prepare small areas bya hand grinder to provide a smooth surface for motion sensorattachment and impact.
Attach the motion sensor firmly to pile i. For piles with diameters larger than mm,attach the accelerometer at a minimum of three locations soFIG. Position the apparatus forapplying the impact force so that the impact is applied axiallywith the pile and at a distance no larger than mm from theaccelerometer. Set up the apparatus for recording, reducing,and displaying data so that it is operational and the force andvelocity signals are zeroed.
Full Description 1. This test method is applicable to long structural elements that function in a manner similar to any deep foundation units such as driven piles, augeured piles, or drilled shafts , regardless of their method of installation provided that they are receptive to low strain impact testing. These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard. No other units of measurement are included in this standard.
ASTM D 5882-16 Compliance Statement
More D Scope 1. This test method is applicable to long structural elements that function in a manner similar to any deep foundation units such as driven piles, augeured piles, or drilled shafts , regardless of their method of installation provided that they are receptive to low strain impact testing. These notes and footnotes excluding those in tables and figures shall not be considered as requirements of the standard.