1、Designation: D 5778 07Standard Test Method forElectronic Friction Cone and Piezocone Penetration Testingof Soils1This standard is issued under the fixed designation D 5778; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the procedure for determiningthe point resistance during penetration of a conical-shapedpe
3、netrometer as it is advanced into subsurface soils at a steadyrate.1.2 This test method is also used to determine the frictionalresistance of a cylindrical sleeve located behind the conicalpoint as it is advanced through subsurface soils at a steady rate.1.3 This test method applies to friction-cone
4、 penetrometersof the electric and electronic type. Field tests usingmechanical-type penetrometers are covered elsewhere by TestMethod D 3441.1.4 This test method can be used to determine porewaterpressures developed during the penetration, thus termed piezo-cone. Porewater pressure dissipation, afte
5、r a push, can also bemonitored for correlation to time rate of consolidation andpermeability.1.5 Additional sensors, such as inclinometer, seismic geo-phones, resistivity, electrical conductivity, dielectric, and tem-perature sensors, may be included in the penetrometer toprovide useful information.
6、 The use of an inclinometer ishighly recommended since it will provide information onpotentially damaging situations during the sounding process.1.6 Cone penetration test data can be used to interpretsubsurface stratigraphy, and through use of site specific corre-lations, they can provide data on en
7、gineering properties of soilsintended for use in design and construction of earthworks andfoundations for structures.1.7 The values stated in SI units are to be regarded asstandard. Within Section 13 on Calculations, SI units areconsidered the standard. Other commonly used units such asthe inch-poun
8、d system are shown in brackets. The various datareported should be displayed in mutually compatible units asagreed to by the client or user. Cone tip projected area iscommonly referred to in square centimetres for convenience.The values stated in each system are not equivalents; therefore,each syste
9、m must be used independently of the other.NOTE 1This test method does not include hydraulic or pneumaticpenetrometers. However, many of the procedural requirements hereincould apply to those penetrometers. Also, offshore/marine CPT systemsmay have procedural differences because of the difficulties o
10、f testing inthose environments (for example, tidal variations, salt water, waves).Mechanical CPT systems are covered under Test Method D 3441.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard
11、 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 3441 Test Method for Mechanical Cone Penetration Testsof SoilD 3740
12、 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionE4 Practices for Force Verification of Testing Machines3. Terminology3.1 Definitions:3.1.1 Definitions are in accordance with Terminology Con-vention
13、(D 653).3.2 Definitions of Terms Specific to This Standard:3.2.1 apparent load transferapparent resistance measuredon either the cone or friction sleeve of an electronic conepenetrometer while that element is in a no-load condition butthe other element is loaded. Apparent load transfer is the sumof
14、cross talk, subtraction error, and mechanical load transfer.3.2.2 baselinea set of zero load readings, expressed interms of apparent resistance, that are used as reference valuesduring performance of testing and calibration.3.2.3 cone tipthe conical point of a cone penetrometer onwhich the end beari
15、ng component of penetration resistance isdeveloped. The cone has a 60 apex angle, a diameter of 35.71This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.02 on Sampling andRelated Field Testing for Soil Evaluations.Curre
16、nt edition approved Nov. 1, 2007. Published December 2007. Originallyapproved in 1995. Last previous edition approved in 2000 as D 5778 95 (2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
17、 volume information, refer to the standards Document Summary page onthe ASTM website.1*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.mm, and a corresponding projected
18、(horizontal plane) surfacearea or cone base area of 10 cm2. Also, enlarged cones of 43.7mm diameter (base area = 15 cm2) are utilized.3.2.4 cone penetration testa series of penetration readingsperformed at one location over the entire vertical depth whenusing a cone penetrometer.Also referred to as
19、a cone sounding.3.2.5 cone penetrometera penetrometer in which the lead-ing end of the penetrometer tip is a conical point designed forpenetrating soil and for measuring the end-bearing componentof penetration resistance.3.2.6 cone resistance, qcthe measured end-bearing com-ponent of penetration res
20、istance. The resistance to penetrationdeveloped on the cone is equal to the vertical force applied tothe cone divided by the cone base area.3.2.7 corrected total cone resistance, qttip resistancecorrected for water pressure acting behind the tip (see 13.2.1).Correction for water pressure requires me
21、asuring water pres-sures with a piezocone element positioned behind the tip atlocation u2(See section 3.2.26). The correction results inestimated total tip resistance, qt.3.2.8 cross talkan apparent load transfer between the coneand the friction sleeve caused by interference between theseparate sign
22、al channels.3.2.9 electronic cone penetrometera friction cone pen-etrometer that uses force transducers, such as strain gauge loadcells, built into a non-telescoping penetrometer tip for measur-ing, within the penetrometer tip, the components of penetrationresistance.3.2.10 electronic piezocone pene
23、trometeran electroniccone penetrometer equipped with a low volume fluid chamber,porous element, and pressure transducer for determination ofporewater pressure at the porous element soil interface.3.2.11 end bearing resistancesame as cone resistance ortip resistance, qc.3.2.12 equilibrium pore water
24、pressure, u0at rest waterpressure at depth of interest. Same as hydrostatic pressure (seeTerminology D 653).3.2.13 excess pore water pressure, Duthe difference be-tween porewater pressure measured as the penetration occurs(u), and estimated equilibrium porewater pressure (u0), or: Du=(uu0). Excess p
25、orewater pressure can either be positive ornegative for shoulder position filters.3.2.14 friction cone penetrometera cone penetrometerwith the capability of measuring the friction component ofpenetration resistance.3.2.15 friction ratio, Rfthe ratio of friction sleeve resis-tance, fs, to cone resist
26、ance, qc, measured at where the middleof the friction sleeve and cone point are at the same depth,expressed as a percentage.3.2.16 friction reducera narrow local protuberance on theoutside of the push rod surface, placed at a certain distanceabove the penetrometer tip, that is provided to reduce the
27、 totalside friction on the push rods and allow for greater penetrationdepths for a given push capacity.3.2.17 friction sleevean isolated cylindrical sleeve sectionon a penetrometer tip upon which the friction component ofpenetration resistance develops. The friction sleeve has asurface area of 150 c
28、m2for 10-cm2cone tips or 225 cm2for15-cm2tips.3.2.18 friction sleeve resistance, fsthe friction componentof penetration resistance developed on a friction sleeve, equalto the shear force applied to the friction sleeve divided by itssurface area.3.2.19 FSOabbreviation for full-scale output. The outpu
29、tof an electronic force transducer when loaded to 100 % ratedcapacity.3.2.20 local side frictionsame as friction sleeve resis-tance, fs(see 3.2.18).3.2.21 penetration resistance measuring systema measur-ing system that provides the means for transmitting informa-tion from the penetrometer tip and di
30、splaying the data at thesurface where it can be seen or recorded.3.2.22 penetrometeran apparatus consisting of a series ofcylindrical push rods with a terminal body (end section), calledthe penetrometer tip, and measuring devices for determinationof the components of penetration resistance.3.2.23 pe
31、netrometer tipthe terminal body (end section) ofthe penetrometer which contains the active elements that sensethe components of penetration resistance. The penetrometer tipmay include additional electronic instrumentation for signalconditioning and amplification.3.2.24 piezoconesame as electronic pi
32、ezocone penetrom-eter (see 3.2.10).3.2.25 piezocone porewater pressure, ufluid pressuremeasured using the piezocone penetration test.3.2.26 piezocone porewater pressure measurement location:u1, u2, u3fluid pressure measured by the piezocone pen-etrometer at specific locations on the penetrometer as
33、follows(1):3u1porous filter location on the midface or tip of thecone, u2porous filter location at the shoulder position behindthe cone tip (standard location) and, u3porous filter locationbehind the friction sleeve.3.2.27 porewater pressuretotal porewater pressure mag-nitude measured during penetra
34、tion (same as 3.2.25 above).3.2.28 porewater pressure ratio parameter, Bqthe ratio ofexcess porewater pressure at the standard measurement loca-tion Du2, to corrected total cone resistance qt, minus the totalvertical overburden stress, svo(see Eq 10).3.2.29 push rodsthe thick-walled tubes or rods us
35、ed toadvance the penetrometer tip.3.2.30 sleeve friction, sleeve, and friction resistancesameas friction sleeve resistance.3.2.31 subtraction erroran apparent load transfer fromthe cone to the friction sleeve of a subtraction type electroniccone penetrometer caused by minor voltage differences inres
36、ponse to load between the two strain element cells.3.3 Abbreviations:3.3.1 CPTabbreviation for the cone penetration test.3The boldface numbers given in parentheses refer to a list of references at theend of the text.D57780723.3.2 PCPT or CPTuabbreviation for piezocone penetra-tion test (note: symbol
37、 “u” added for porewater pressuremeasurements).3.3.3 CPTabbreviation for the piezocone penetrationtest with dissipation phases of porewater pressures ().3.3.4 SCPTuabbreviation for seismic piezocone test (in-cludes one or more geophones to allow downhole geophysicalwave velocity measurements).3.3.5
38、RCPTuabbreviation for resistivity piezocone (in-cludes electrical conductivity or resistivity module).4. Summary of Test Method4.1 A penetrometer tip with a conical point having a 60apex angle and a cone base area of 10 or 15 cm2is advancedthrough the soil at a constant rate of 20 mm/s. The force on
39、 theconical point (cone) required to penetrate the soil is measuredby electrical methods, at a minimum of every 50 mm ofpenetration. Improved resolution may often be obtained at 20-or 10-mm interval readings. Stress is calculated by dividing themeasured force (total cone force) by the cone base area
40、 toobtain cone resistance, qc.4.2 A friction sleeve is present on the penetrometer imme-diately behind the cone tip, and the force exerted on the frictionsleeve is measured by electrical methods at a minimum ofevery 50 mm of penetration. Stress is calculated by dividingthe measured axial force by th
41、e surface area of the frictionsleeve to determine sleeve resistance, fs.4.3 Most modern penetrometers are capable of registeringpore water pressure induced during advancement of the pen-etrometer tip using an electronic pressure transducer. Thesepenetrometers are called “piezocones.” The piezocone i
42、s ad-vanced at a rate of 20 mm/s, and readings are taken at aminimum of every 50 mm of penetration. The dissipation ofeither positive or negative excess porewater pressure can bemonitored by stopping penetration, unloading the push rod, andrecording porewater pressure as a function of time. Whenpore
43、water pressure becomes constant it is measuring theequilibrium value (designated u0) or piezometric level at thatdepth.5. Significance and Use5.1 Tests performed using this test method provide a de-tailed record of cone resistance which is useful for evaluationof site stratigraphy, homogeneity and d
44、epth to firm layers,voids or cavities, and other discontinuities.The use of a frictionsleeve and porewater pressure element can provide an estimateof soil classification, and correlations with engineering prop-erties of soils. When properly performed at suitable sites, thetest provides a rapid means
45、 for determining subsurface condi-tions.5.2 This test method provides data used for estimatingengineering properties of soil intended to help with the designand construction of earthworks, the foundations for structures,and the behavior of soils under static and dynamic loads.5.3 This method tests t
46、he soil in-situ and soil samples arenot obtained. The interpretation of the results from this testmethod provides estimates of the types of soil penetrated.Engineers may obtain soil samples from parallel borings forcorrelation purposes but prior information or experience maypreclude the need for bor
47、ings.6. Interferences6.1 Refusal, deflection, or damage to the penetrometer mayoccur in coarse grained soil deposits with maximum particlesizes that approach or exceed the diameter of the cone.6.2 Partially lithified and lithified deposits may cause re-fusal, deflection, or damage to the penetromete
48、r.6.3 Standard push rods can be damaged or broken underextreme loadings. The amount of force that push rods are ableto sustain is a function of the unrestrained length of the rodsand the weak links in the push rod-penetrometer tip string suchas push rod joints and push rod-penetrometer tip connectio
49、ns.The force at which rods may break is a function of theequipment configuration and ground conditions during pen-etration. Excessive rod deflection is the most common causefor rod breakage.7. Apparatus7.1 Friction Cone PenetrometerThe penetrometer tipshould meet requirements as given below and in 10.1.Inaconventional friction-type cone penetrometer, the forces at thecone tip and friction sleeve are measured by two load cellswithin the penetrometer. Either independent load cells orsubtraction-type penetrometers are acceptable for use (Fig.
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