1、Designation: D3441 16Standard Test Method forMechanical Cone Penetration Testing of Soils1This standard is issued under the fixed designation D3441; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method covers the procedure for determining
3、the point resistance during penetration of a conical-shapedpenetrometer as it is advanced into subsurface soils at a steadyrate.1.2 This test method may also used to determine thefrictional resistance of a cylindrical sleeve located behind theconical point as it is advanced through subsurface soils
4、at asteady rate.1.3 This test method applies to mechanical-type penetrom-eters. Field tests using penetrometers of electronic type arecovered elsewhere by Test Method D5778.1.4 Cone penetration test data can be used to interpretsubsurface stratigraphy, and through use of site specificcorrelations, t
5、hey can provide data on engineering properties ofsoils intended for use in design and construction of earthworksand foundations for structures.1.5 Mechanical penetrometers of the type described in thistest method operate either continually (in which cone penetra-tion resistance is measured while con
6、e and push rods aremoving continuously until stopped for the addition of a pushrod) or discontinuously (in which cone penetration resistanceand, optionally, sleeve friction are measured during a penetra-tion stop of the push rods) using an inner rod system and apenetrometer tip (that must be telesco
7、ping in case of discon-tinuous operation).1.6 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotesshall not be considered as requirements of the standard. Theillustrations included in this standard are intended only forexplanatory or a
8、dvisory use.1.7 UnitsThe values stated in SI units are to be regardedas standard. No other units of measurement are included in thisstandard. Reporting of test results in units other than SI shallnot be regarded as nonconformance with this test method.1.8 All observed and calculated values shall con
9、form to theguidelines for significant digits and rounding established inPractice D6026 unless superseded by this standard.1.8.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as theindustry standard. In addition, they are representative of
10、 thesignificant digits that should generally be retained. The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincrease or reduce significant digits of reported da
11、ta to com-mensurate with these considerations. It is beyond the scope ofthis standard to consider significant digits used in analysismethods for engineering design.1.9 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
12、 user of this standard 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:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD3740 Practice for Minimum Requirements for Agen
13、ciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD5778 Test Method for Electronic Friction Cone and Piezo-cone Penetration Testing of SoilsD6026 Practice for Using Significant Digits in GeotechnicalData3. Terminology3.1 Definitions:1This test met
14、hod is under the jurisdiction of Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.02 on Sampling and RelatedField Testing for Soil Evaluations.Current edition approved July 1, 2016. Published July 2016. Originally approvedin 1975. Last previous edition approved in 1
15、998 as D3441 98, which waswithdrawn January 2014 and reinstated in July 2016. DOI: 10.1520/D3441-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Do
16、cument Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.1 For definitions of common technical terms in thisstandard, refer to Terminol
17、ogy D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 cone tip, nthe conical point of a cone penetrometeron which the end bearing component of penetration resistanceis developed. The cone has a 60 apex angle, a diameter of 35.7mm, and a corresponding projected (horizontal plane) surfacea
18、rea or cone base area of 1000 mm2.3.2.2 cone penetrometer, na penetrometer in which theleading end of the penetrometer tip is a conical point designedfor penetrating soil and for measuring the end-bearing compo-nent of penetration resistance.3.2.3 cone resistance, qc,nthe measured end-bearingcompone
19、nt of penetration resistance.3.2.3.1 DiscussionThe resistance to penetration devel-oped on the cone is equal to the vertical force applied to thecone divided by the cone base area. Cone resistance may varyfrom cone resistance measured by the electronic cone test (TestMethod D5778) (see 4.4.1).3.2.4
20、cone penetration test (CPT), na series of penetrationreadings performed at one location over the entire verticaldepth when using a cone penetrometer. Also referred to as acone sounding.3.2.5 friction cone penetrometer, ncone penetrometer withthe capability of measuring the friction component of pene
21、tra-tion resistance.3.2.6 friction ratio, Rf,nthe ratio of friction sleeve resis-tance to cone resistance, fs/ qc, expressed as a percentage.3.2.6.1 DiscussionThe friction ratio for mechanical pen-etrometers is not comparable to the friction ratio measured byelectronic or electrical penetrometer (Te
22、st Method D5778) (see4.4.1).3.2.7 friction sleeve resistance, fs,nthe friction compo-nent of penetration resistance developed on a friction sleeve,equal to the shear force applied to the friction sleeve divided byits surface area.3.2.8 friction sleeve, nan isolated section on a penetrom-eter tip upo
23、n which the friction component of penetrationresistance develops.3.2.9 friction reducer, na narrow local protuberance on theoutside of the push rod surface, placed above the penetrometertip, that is provided to reduce the total side friction on the pushrods and allow for greater penetration depths f
24、or a given pushcapacity.3.2.10 inner rods, nrods that slide inside the push rods toextend the telescoping penetrometer tip and friction sleeve(when so equipped) of a mechanical penetrometer.3.2.11 mechanical penetrometer, na penetrometer thatuses a set of inner rods to operate a telescoping penetrom
25、etertip and to transmit the component(s) of penetration resistanceto the surface for measurement.3.2.12 penetrometer, nan apparatus consisting of a seriesof cylindrical push rods with a terminal body (end section),called the penetrometer tip, and measuring devices for deter-mination of the component
26、s of penetration resistance.3.2.13 penetrometer tip, nthe end section of thepenetrometer, which comprises the cone tip, and in the case ofthe friction-cone penetrometer, the friction sleeve.3.2.14 push rods, nthe thick-walled tubes used to advancethe penetrometer tip.4. Significance and Use4.1 Tests
27、 performed using this test method provide a de-tailed record of cone resistance that is useful for evaluation ofsite stratigraphy, homogeneity and depth to firm layers, voidsor cavities, and other discontinuities. The use of a frictionsleeve can provide an estimate of soil classification, andcorrela
28、tions with engineering properties of soils. When prop-erly performed at suitable sites, the test provides a rapid meansfor determining subsurface conditions.4.2 This test method provides data used for estimatingengineering properties of soil intended to help with the designand construction of earthw
29、orks, the foundations for structures,and the behavior of soils under static and dynamic loads.4.3 This method tests the 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 s
30、amples from parallel borings forcorrelation purposes, but prior information or experience maypreclude the need for borings.4.4 Electronic cone data (D5778) is generally more reliableand reproducible. Mechanical cone equipment may proveuseful when penetrating strong or rocky soils that mightdamage el
31、ectronic cone equipment. Mechanical cone equip-ment typically requires less operator expertise to operate and toproperly maintain than electronic cone equipment. However,mechanical cone equipment is not recommended for liquefac-tion investigations or investigations where a high level ofquality assur
32、ance must be obtained.4.4.1 Cone test data from the mechanical cone (D3441) aregenerally comparable with the electronic cone (D5778) butthere are differences because of the geometry of the cone andfriction sleeve sections. Users of these test data are cautionedthat engineering correlations from elec
33、tronic cones should notbe used for these mechanical cones. Users should verify thatthe application of empirical correlations such as those predict-ing soil types from Rfare for the correct penetrometer.3NOTE 1The quality of the result produced by this standard isdependent on the competence of the pe
34、rsonnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does no
35、t in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides means of evaluating some of these factors.5. Interferences5.1 The use of penetrometer components that do not meetrequired tolerances or show visible signs of non-symmetricwear can result in erroneous
36、penetration resistance data.3De Ruiter, J., “Electric Penetrometer for Site Investigations,” Journal of theSoil Mechanics and Foundation Division, Vol. 97, No. 2, February 1971, pp457-472.D3441 1625.2 Push rods not meeting requirements of 6.3 may result inexcessive directional penetrometer drift and
37、 possibly unreliablepenetration resistance values.5.3 Soil particles and corrosion can increase the frictionbetween inner rods and push rods, possibly resulting insignificant errors in the measurement of the resistance compo-nent(s). Clean and lubricate the inner rods.5.4 If a mantle of reduced diam
38、eter is attached above thecone (as described in 6.1.2) for the purpose of reducing frictionin the mantle above the cone tip, a small but unknown amountof side friction may develop along this mantle and will beincluded in the cone resistance.5.5 If the proper rate of advance of the penetrometer is no
39、tmaintained for the entire stroke and through the measurementintervals, penetration resistance data will be erroneous.5.6 To avoid drilling disturbance effects, a cone soundingshall not be performed any closer than 25 borehole diametersto an unfilled or uncased borehole.5.7 When performing cone pene
40、tration testing in a preboredhole, estimate the depth of drilling disturbance below the openhole and note the penetration resistance data obtained in thiszone. The depth of disturbance is typically assumed to be equalto at least three borehole diameters, but depends on drillingtechnique and stratigr
41、aphy.5.8 Significant bending of the push rods can influencepenetration resistance data. The use of a rod guide is recom-mended at the base of the thrust machine and also in preboredholes to help prevent push rod bending.5.9 Passing through or alongside obstructions may deflectthe penetrometer and in
42、duce directional drift. Note any indi-cations of obstructions, such as buried logs or boulders, and bealert for subsequent improper penetrometer tip operation.5.10 Refusal, deflection, or damage to the penetrometer mayoccur in coarse grained soil deposits with maximum particlesizes that approach or
43、exceed the diameter of the cone.Partially lithified and lithified deposits may also cause refusal,deflection, or damage to the penetrometer.5.11 Especially in soft soils the thrust resistance should becorrected to include the accumulated weight of the inner rodsfrom the penetrometer tip to the topmo
44、st rod.6. Apparatus6.1 Mechanical Penetrometers:6.1.1 The sliding mechanism necessary in a mechanicalpenetrometer tip must allow a downward movement of thecone in relation to the push rods of at least 35 mm.NOTE 2For certain combinations of depth and tip resistance(s), theelastic compression of the
45、inner rods may exceed the downward strokethat the thrust machine can apply to the inner rods relative to the pushrods. In this case, the tip will not extend and the thrust readings will riseelastically to the end of the machine stroke and then jump abruptly whenthe thrust machine makes contact with
46、the push rods. In such cases theinner rods should be extended.6.1.2 The mechanical penetrometer tip design shall includeprotection against soil entering the sliding mechanism andaffecting the resistance component(s). Fig. 1 shows the designand action of one mechanical cone penetrometer tip where ama
47、ntle of reduced diameter is attached above the cone tominimize possible soil contamination of the sliding mecha-nism.6.1.3 Friction Cone PenetrometerFig. 2 shows the designand action of one telescoping mechanical friction cone pen-etrometer tip. The lower part of the tip, including a mantle towhich
48、the cone attaches, advances first until the flange engagesthe friction sleeve and then both advance.FIG. 1 Example of a Mechanical Cone Penetrometer Tip (DutchMantle Cone)FIG. 2 Example of a Mechanical Friction-Cone Penetrometer Tip(Begemann Friction-Cone)D3441 163NOTE 3The shoulder at the lower end
49、 of the friction sleeve encountersend-bearing resistance. In sand, as much as two thirds of the sleeveresistance may consist of bearing on this shoulder. Ignore this effect in softto medium clays.6.2 Cone tip and Friction Sleeve:6.2.1 Cone TipThe cone tip shall have 60(65) pointangle and a base diameter dcbetween 35.3 and 36 mm,resulting in a projected area of approximately 1,000 mm2. Thepoint of the cone tip shall have a radius less than or equal to 3mm.6.2.2 Friction SleeveThe friction sleeve shall have adiameter dfbetween dcand dc+ 0.35 mm, with dcthe
