1、Designation:D577807 Designation: D5778 12Standard Test Method forElectronic Friction Cone and Piezocone Penetration Testingof Soils1This standard is issued under the fixed designation D5778; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the procedure for determining the point resistance during penetration of
3、a conical-shapedpenetrometer as it is advanced into subsurface soils at a steady rate.1.2 This test method is also used to determine the frictional resistance of a cylindrical sleeve located behind the conical pointas it is advanced through subsurface soils at a steady rate.1.3 This test method appl
4、ies to friction-cone penetrometers of the electric and electronic type. Field tests using mechanical-typepenetrometers are covered elsewhere by Test Method D3441.1.4 This test method can be used to determine porewater pressures developed during the penetration, thus termed piezocone.Porewater pressu
5、re dissipation, after a push, can also be monitored for correlation to time rate of consolidation and permeability.1.5 Additional sensors, such as inclinometer, seismic geophones (Test Methods D7400), resistivity, electrical conductivity,dielectric, and temperature sensors, may be included in the pe
6、netrometer to provide useful information. The use of an inclinometeris highly recommended since it will provide information on potentially damaging situations during the sounding process.1.6 Cone penetration test data can be used to interpret subsurface stratigraphy, and through use of site specific
7、 correlations, theycan provide data on engineering properties of soils intended for use in design and construction of earthworks and foundations forstructures.1.7 The values stated in SI units are to be regarded as standard. Within Section 13 on Calculations, SI units are considered thestandard. Oth
8、er commonly used units such as the inch-pound system are shown in brackets. The various data reported should bedisplayed in mutually compatible units as agreed to by the client or user. Cone tip projected area is commonly referred to in squarecentimetres for convenience. The values stated in each sy
9、stem are not equivalents; therefore, each system mustshall be usedindependently of the other.NOTE 1This test method does not include hydraulic or pneumatic penetrometers. However, many of the procedural requirements herein could applyto those penetrometers. Also, offshore/marine CPT systems may have
10、 procedural differences because of the difficulties of testing in those environments(for example, tidal variations, salt water, waves). Mechanical CPT systems are covered under Test Method D3441.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use
11、. 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 FluidsD3441 Test Method
12、for Mechanical Cone Penetration Tests of SoilD3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD7400 Test Methods for Downhole Seismic TestingE4 Practices for Force Verification of Testing Machines1
13、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 Nov. 1, 2007. Published December 2007. Originally approved in 1995. Last previo
14、us edition approved in 2000 as D577895 (2000). DOI:10.1520/D5778-07.Current edition approved Jan. 1, 2012. Published February 2012. Originally approved in 1995. Last previous edition approved in 2007 as D577807. DOI:10.1520/D5778-12.2For referencedASTM standards, visit theASTM website, www.astm.org,
15、 or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes
16、 have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, 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
17、 document.*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.3. Terminology3.1 Definitions:3.1.1 Definitions are in accordance with Terminology Convention (D653).3.2 Defin
18、itions of Terms Specific to This Standard:3.2.1 apparent load transferapparent resistance measured on either the cone or friction sleeve of an electronic conepenetrometer while that element is in a no-load condition but the other element is loaded.Apparent load transfer is the sum of crosstalk, subt
19、raction error, and mechanical load transfer.3.2.2 baselinea set of zero load readings, expressed in terms of apparent resistance, that are used as reference values duringperformance of testing and calibration.3.2.3 cone tipthe conical point of a cone penetrometer on which the end bearing component o
20、f penetration resistance isdeveloped. The cone has a 60 apex angle, a diameter of 35.7 mm, and a corresponding projected (horizontal plane) surface areaor cone base area of 10 cm2. Also, enlarged cones of 43.7 mm diameter (base area = 15 cm2) are utilized.3.2.4 cone penetration testa series of penet
21、ration readings performed at one location over the entire vertical depth when usinga cone penetrometer. Also referred to as a cone sounding.3.2.5 cone penetrometera penetrometer in which the leading end of the penetrometer tip is a conical point designed forpenetrating soil and for measuring the end
22、-bearing component of penetration resistance.3.2.6 cone resistance, qcthe measured end-bearing component of penetration resistance. The resistance to penetrationdeveloped on the cone is equal to the vertical force applied to the cone divided by the cone base area.3.2.7 corrected total cone resistanc
23、e, qttip resistance corrected for water pressure acting behind the tip (see 13.2.1).Correction for water pressure requires measuring water pressures with a piezocone element positioned behind the tip at locationu2(See section 3.2.26). The correction results in estimated total tip resistance, qt.3.2.
24、8 cross talkan apparent load transfer between the cone and the friction sleeve caused by interference between the separatesignal channels.3.2.9 electronic cone penetrometera friction cone penetrometer that uses force transducers, such as strain gauge load cells,built into a non-telescoping penetrome
25、ter tip for measuring, within the penetrometer tip, the components of penetration resistance.3.2.10 electronic piezocone penetrometeran electronic cone penetrometer equipped with a low volume fluid chamber, porouselement, and pressure transducer for determination of porewater pressure at the porous
26、element soil interface. an electronic conepenetrometer equipped with a low volume fluid chamber, porous element, and pressure transducer for determination of porewaterpressure at the porous element soil interface measured simultaneously with end bearing and frictional components of penetrationresist
27、ance.3.2.11 end bearing resistancesame as cone resistance or tip resistance, qc.3.2.12 equilibrium pore water pressure, u0at rest water pressure at depth of interest. Same as hydrostatic pressure (seeTerminology D653). at rest water pressure at depth of interest.3.2.13 excess pore water pressure, Du
28、the difference between porewater pressure measured as the penetration occurs (u), andestimated equilibrium porewater pressure (u0), or: Du=(uu0). Excess porewater pressure can either be positive or negative forshoulder position filters.3.2.14 friction cone penetrometera cone penetrometer with the ca
29、pability of measuring the friction component of penetrationresistance.3.2.15 friction ratio, Rfthe ratio of friction sleeve resistance, fs, to cone resistance, qc, measured at where the middle of thefriction sleeve and cone point are at the same depth, expressed as a percentage. , measured at where
30、the middle of the friction sleeveand cone point are at the same depth, expressed as a percentage.NOTE 2Some methods to interpret CPT data use friction ratio defined as the ratio of sleeve friction, fs, to cone resistance corrected for pore pressureeffects qt, (4). It is not within the scope of this
31、standard to recommend which methods of interpretation are to be used.3.2.16 friction reducera narrow local protuberance on the outside of the push rod surface, placed at a certain distance abovethe penetrometer tip, that is provided to reduce the total side friction on the push rods and allow for gr
32、eater penetration depths fora given push capacity.3.2.17 friction sleevean isolated cylindrical sleeve section on a penetrometer tip upon which the friction component ofpenetration resistance develops. The friction sleeve has a surface area of 150 cm2for 10-cm2cone tips or 225 cm2for 15-cm2tips.3.2.
33、18 friction sleeve resistance, fsthe friction component of penetration resistance developed on a friction sleeve, equal tothe shear force applied to the friction sleeve divided by its surface area.3.2.19 FSOabbreviation for full-scale output. The output of an electronic force transducer when loaded
34、to 100 % ratedcapacity.3.2.20 local side frictionsame as friction sleeve resistance, fs(see 3.2.18).3.2.21 penetration resistance measuring systema measuring system that provides the means for transmitting information fromthe penetrometer tip and displaying the data at the surface where it can be se
35、en or recorded.3.2.22 penetrometeran apparatus consisting of a series of cylindrical push rods with a terminal body (end section), called thepenetrometer tip, and measuring devices for determination of the components of penetration resistance.3.2.23 penetrometer tipthe terminal body (end section) of
36、 the penetrometer which contains the active elements that sense theD5778 122components of penetration resistance. The penetrometer tip may include additional electronic instrumentation for signalconditioning and amplification.3.2.24 piezoconesame as electronic piezocone penetrometer (see 3.2.10).3.2
37、.25 piezocone porewater pressure, ufluid pressure measured using the piezocone penetration test.3.2.26 piezocone porewater pressure measurement location: u1, u2, u3fluid pressure measured by the piezocone penetrometerat specific locations on the penetrometer as follows (1, 2, 3):3: u1porous filter l
38、ocation on the midface or tip of the cone, u2porous filter location at the shoulder position behind the cone tip (standard location) and, u3porous filter location behind the friction sleeve.3.2.27 porewater pressuretotal porewater pressure magnitude measured during penetration (same as 3.2.25 above)
39、.3.2.28 porewater pressure ratio parameter, Bqthe ratio of excess porewater pressure at the standard measurement locationDu2, to corrected total cone resistance qt, minus the total vertical overburden stress, svo(see Eq 10).3.2.29 push rodsthe thick-walled tubes or rods used to advance the penetrome
40、ter tip.3.2.30 sleeve friction, sleeve, and friction resistancesame as friction sleeve resistance.3.2.31 subtraction erroran apparent load transfer from the cone to the friction sleeve of a subtraction type electronic conepenetrometer caused by minor voltage differences in response to load between t
41、he two strain element cells.3.3 Abbreviations:3.3.1 CPTabbreviation for the cone penetration test.3.3.2 PCPT or CPTuPCPT (1, 2) or CPTu (3)abbreviation for piezocone penetration test (note: symbol “u” added forporewater pressure measurements).3.3.3 CPTabbreviation for the piezocone penetration test
42、with dissipation phases of porewater pressures ().3.3.4 SCPTuabbreviation for seismic piezocone test Test Methods D7400 (includes one or more geophones to allowdownhole geophysical wave velocity measurements).3.3.5 RCPTuabbreviation for resistivity piezocone (includes electrical conductivity or resi
43、stivity module).4. Summary of Test Method4.1 A penetrometer tip with a conical point having a 60 apex angle and a cone base area of 10 or 15 cm2is advanced throughthe soil at a constant rate of 20 mm/s. The force on the conical point (cone) required to penetrate the soil is measured by electricalmet
44、hods, at a minimum of every 50 mm of penetration. Improved resolution may often be obtained at 20- or 10-mm intervalreadings. Stress is calculated by dividing the measured force (total cone force) by the cone base area to obtain cone resistance, qc.4.2 Afriction sleeve is present on the penetrometer
45、 immediately behind the cone tip, and the force exerted on the friction sleeveis measured by electrical methods at a minimum of every 50 mm of penetration. Stress is calculated by dividing the measured axialforce by the surface area of the friction sleeve to determine sleeve resistance, fs.4.3 Most
46、modern penetrometers are capable of registering pore water pressure induced during advancement of the penetrometertip using an electronic pressure transducer. These penetrometers are called “piezocones.” The piezocone is advanced at a rate of20 mm/s, and readings are taken at a minimum of every 50 m
47、m of penetration. The dissipation of either positive or negative excessporewater pressure can be monitored by stopping penetration, unloading the push rod, and recording porewater pressure as afunction of time. When porewater pressure becomes constant it is measuring the equilibrium value (designate
48、d u0) or piezometriclevel at that depth.5. Significance and Use5.1 Tests performed using this test method provide a detailed record of cone resistance which is useful for evaluation of sitestratigraphy, homogeneity and depth to firm layers, voids or cavities, and other discontinuities. The use of a
49、friction sleeve andporewater pressure element can provide an estimate of soil classification, and correlations with engineering properties of soils.When properly performed at suitable sites, the test provides a rapid means for determining subsurface conditions.5.2 This test method provides data used for estimating engineering properties of soil intended to help with the design andconstruction of earthworks, the foundations for structures, and the behavior of soils under static and dynamic loads.5.3This method tests the soil in-situ an
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