1、Designation: D4633 10D4633 16Standard Test Method forEnergy Measurement for Dynamic Penetrometers1This standard is issued under the fixed designation D4633; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This test method describes procedures for measuring the energy that enters the penetrometer drill rod string during dynamicpe
3、netrometer testing of soil due to the hammer impact.1.2 This test has particular application to the comparative evaluation of N-values obtained from the Standard Penetration Tests(SPT) of soils in an open hole as in Test Method D1586 and Practice D6066. This procedure may also be applicable to other
4、dynamic penetrometer tests.1.3 The values stated in SI units are to be regarded as standard. The inch-pound units given in parentheses are mathematicalconversions which are provided for information purposes only and are not considered standard. Reporting of test results in unitsother than SI shall n
5、ot be regarded as nonconformance with this test method.1.3.1 The converted inch-pound units use the gravitational system of units. In this system, the pound (lbf) represents a unit offorce (weight), while the unit for mass is slugs. The converted slug unit is not given, unless dynamic (F = ma) calcu
6、lations areinvolved.1.4 LimitationsThis test method applies to penetrometers driven from above the ground surface. It is not intended for use withdown-hole hammers.1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in PracticeD6026.
7、1.5.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industrystandard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do notconsider material variation, purpose
8、for obtaining the data, special purpose studies, or any considerations for the users objectives;and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations.It is beyond the scope of this standard to consider significant digits used
9、 in analytical methods for engineering design.1.6 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to howthe data can be applied in design or other uses, since that is beyond its scope. Practicetext of this standard references notes
10、andfootnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not beconsidered as requirements of the D6066 specifies how these data may be normalized.standard.1.7 This standard does not purport to address all of the safety concerns, if any,
11、 associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and Contained
12、FluidsD1586 Test Method for Penetration Test (SPT) and Split-Barrel Sampling of SoilsD3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD6026 Practice for Using Significant Digits in Geotechnical Dat
13、a1 This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.02 on Sampling and RelatedField Testing for Soil Evaluations.Current edition approved Jan. 1, 2010July 1, 2016. Published February 2010July 2016. Originally appro
14、ved in 2005. Last previous edition approved in 20052010 asD4633 05.D4633 10. DOI: 10.1520/D4633-10.10.1520/D4633-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to t
15、he standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes a
16、ccurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Har
17、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D6066 Practice for Determining the Normalized Penetration Resistance of Sands for Evaluation of Liquefaction Potential3. Terminology3.1 Definitions:3.1.1 For definitions of common technical terms used in this standard, refer to
18、Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.1.1 acceleration transducer, or accelerometerinstrument attached on, around, or within a continuous column of drill rodsto measure the time-varying acceleration generated in the drill rods by the impact of the hammer.3.2.1 anvilan
19、vil, nthe mass at the top of the drill rods that is struck by the hammer.3.2.2 drill rodsrods, nthe steel rods connecting the hammer system above the ground surface to the sampler below thesurface.3.1.4 force transducera section of drill rod instrumented with strain gages and inserted into the conti
20、nuous column of drillrods to measure the time-varying force generated in the drill rods by the impact of the hammer.3.2.3 hammerhammer, nan impact mass that is raised and dropped to create an impact on the drill rods.3.2.4 impedance (of the drill rod)rod), na property of the drill rod equal to the d
21、rill rod elastic modulus times the crosssectional area divided by the velocity of wave propagation.3.2.5 instrumented subassemblysubassembly, na short section of drill rod instrumented to measure force and accelerationwhich is inserted at the top of the drill rod and below the anvil.3.2.6 penetromet
22、erpenetrometer, nany sampler, cone, blade, or other instrument placed at the bottom of the drill rods.3.2 Symbols:EFV = the energy transmitted to the drill rod from the hammer during the impact event (see 7.10).ETR = (EFV / PE) ratio of the measured energy transferred to the drill rods to the theore
23、tical potential energy.L = length between the location of transducers on the instrumented subassembly and the bottom of the penetrometer.2L/c = the time required for the stress wave (traveling at a known wave speed, c, in steel of 5123 m/s (16 810 ft/s) to travelfrom the measurement location to the
24、bottom of the penetrometer and return to the measurement location.N-value = the number of hammer blows required to advance the sampler the last 0.305 m (1.00 ft) of the 0.457 m (1.5 ft) drivenduring an SPT test.PE = the theoretical potential energy of the hammer positioned at the specified height ab
25、ove the impact surface.3.3 Symbols:3.3.1 EFVthe energy transmitted to the drill rod from the hammer during the impact event (see 8.1).3.3.2 ETR(EFV / PE) ratio of the measured energy transferred to the drill rods to the theoretical potential energy.3.3.3 Llength between the location of transducers o
26、n the instrumented subassembly and the bottom of the penetrometer.3.3.4 2L/cthe time required for the stress wave (traveling at a known wave speed, c, in steel of 5123 m/s (16 810 ft/s) to travelfrom the measurement location to the bottom of the penetrometer and return to the measurement location.3.
27、3.5 N60standard penetration resistance adjusted to a 60 % drill rod energy transfer ratio.3.3.6 N-valuethe number of hammer blows required to advance the sampler the last 0.305 m (1.00 ft) of the 0.457 m (1.5 ft)driven during an SPT test.3.3.7 PEthe theoretical potential energy of the hammer positio
28、ned at the specified height above the impact surface.4. Significance and Use4.1 Various driven in situ penetrometers are used to evaluate the engineering behavior of soils. The Standard Penetration Testis the most common type. Engineering properties can be estimated on the basis of empirical correla
29、tions between N-values andsoil density, strength or stiffness. Alternatively, the N-value can be used directly in foundation design using correlations to designparameters such as allowable bearing pressure or pile capacity. The N-value depends on the soil properties but also on the mass,geometry, st
30、roke, anvil, and operating efficiency of the hammer. This energy measurement procedure can evaluate variations ofN-value resulting from differences in the hammer system. See also Refs (1-6).34.2 There is an approximate, linear relationship between the incremental penetration of a penetrometer and th
31、e energy from thehammer that enters the drill rods, and therefore an approximate inverse relationship between the N-value and the energy deliveredto the drill rods.NOTE 1Since the measured energy includes the extra potential energy effect due to the set per blow, tests for energy evaluation of the h
32、ammer systemsshould be limited to moderate N-value ranges between 10 and 50 (Ref (7).3 The boldface numbers in parentheses refer to the list of references at the end of this standard.D4633 1624.3 Stress wave energy measurements on penetrometers may evaluate both operator-dependent cathead and rope h
33、ammersystems and relatively operator-independent automatic systems.4.4 The energy measurement has direct application for liquefaction evaluation for sands as referenced in Practice D6066.4.5 This test method is useful for comparing the N-values produced by different equipment or operators performing
34、 SPT testingat the same site, aiding the design of penetrometer systems, training of dynamic penetrometer system operators, and developingconversion factors between different types of dynamic penetration tests.NOTE 2The quality of the result produced by this standard is dependent on the competence o
35、f the personnel performing it, and the suitability of theequipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing andinspection. testing/sampling/inspection/etc. Users of this standard are cautioned that comp
36、liance with Practice D3740 does not in itself assure reliableresults. Reliable results depend on many factors: Practice D3740 provides a means of evaluating some of those factors.5. Apparatus5.1 Apparatus for MeasurementAn instrumented subassembly defined in 3.1.73.2.5 shall be inserted at the top o
37、f the drill rodstring directly below the hammer and anvil system so that the hammer impact is transmitted through the anvil into the instrumentedsubassembly and then into the drill rods. The subassembly shall be made of steel drill rod and shall be at least 0.60 m (2 ft) inlength. The measurement lo
38、cation of force and accelerationthe strain gauges and accelerometers shall be located at least 0.30 m(1 ft) below the top of the instrumented subassembly, and shall be at least three diameters away from any cross sectional areachange.NOTE 3While having the same nominal area for the instrumented subs
39、ectionsubassembly as the drill string is desirable, variations in area areunavoidable since (a) the drill rods wear, (b) drill rod manufacture tolerance of wall thickness is rather loose, (c) joints already impose significant crosssection changes far larger than the variation of cross section change
40、s found among common drill rod types (for example, AW, BW, NW or N3), and (d)many drillers have and therefore mix both heavy and light section rods, particularly of the NW type), making it practically impossible to measure withidentical cross sections.5.2 Apparatus to Measure ForceThe force in the d
41、rill rods Force data shall be measured by instrumenting the subassemblywith obtained by attaching foil strain gagesgauges in a full bridge circuit. The gagescircuit to the instrumented subassembly. Thegauges shall be arranged symmetrically such that all bending effects are canceled. The instrumented
42、 rod section subassembly shallhave a minimum of two such full bridge circuits. Transducer systems that insert massive elements or load cells with stiffnessproperties substantially different than those of the rods themselves are specifically prohibited.5.3 Apparatus to Measure AccelerationAcceleratio
43、n data shall be obtained with a minimum of two accelerometers attachedon diametrically opposite sides of the drill rodinstrumented subassembly within 100 mm (4 in.) of the force measurement location.The accelerometers shall be aligned axially with the rod in their sensitivesensing direction and shal
44、l be bolted, glued, or weldedto the rod with small rigid (solid, nearly cubic shape) metal mounts. Overhanging brackets that can bend during impact and plasticmounting blocks are prohibited. Accelerometers shall be linear to at least 10 000 g and have a useable frequency response to atleast 4.5 kHz.
45、NOTE 4The rigidity of the accelerometer mounting block can be assessed by comparing the rise times of the velocity to the force signal.5.4 Apparatus for Recording, Processing and Displaying Data:5.4.1 GeneralThe force and acceleration signals from the hammer impact shall be transmitted to an instrum
46、ent for recording,processing, and displaying data to allow determination of the force and velocity versus time. The apparatus shall provide powerand signal conditioning for all transducers. There are two forms of data acquisition systems. Analog systems electronicallyintegrate measured acceleration
47、to velocity through electronic circuitry and digitize the resulting velocity. Digital systems acquireacceleration data and digitally integrate acceleration to velocity.5.4.2 Analog SystemsThe signal conditioning system shall apply a low-pass filter to both force and velocity with a cutofffrequency o
48、f 2 kHz or higher (preferably 5 kHz). Data acquisition sampling rate shall be at least 5five times the low-pass filterfrequency to avoid signal aliasing. Automatic balancing must be turned off during the impact event.5.4.3 Digital SystemsThe signal conditioning shall apply a low-pass filter to both
49、force and acceleration with a cutofffrequency of 5 kHz or higher (preferably 25 kHz) (Ref (8). To avoid aliasing, data acquisition sampling rate shall be at least 10tentimes the low-pass filter frequency for single sampling of each data point, or at least 5five times the low-pass filter frequency foranalog to digital convertors with oversampling if the oversampling rate is at least 256 times the retained sampling rate.5.4.4 Apparatus for RecordingThe apparatus shall sample each signal and record the magnitude versus time of each sensorin
