1、Designation: D 6067 96 (Reapproved 2003)Standard Guide forUsing the Electronic Cone Penetrometer for EnvironmentalSite Characterization1This standard is issued under the fixed designation D 6067; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、of revision, the year of 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. Scope1.1 The electronic cone penetrometer test often is used todetermine subsurface stratigraphy for
3、geotechnical and envi-ronmental site characterization purposes (1).2The geotechnicalapplication of the electronic cone penetrometer test is dis-cussed in detail in Test Method D 5778, however, the use of theelectronic cone penetrometer test in environmental site char-acterization applications involv
4、es further considerations thatare not discussed.1.2 The purpose of this guide is to discuss aspects of theelectronic cone penetrometer test that need to be consideredwhen performing tests for environmental site characterizationpurposes.1.3 The electronic cone penetrometer test for environmentalsite
5、characterization projects often requires steam cleaning thepush rods and grouting the hole. There are numerous ways ofcleaning and grouting depending on the scope of the project,local regulations, and corporate preferences. It is beyond thescope of this guide to discuss all of these methods in detai
6、l. Adetailed explanation of grouting procedures is discussed inGuide D 6001.1.4 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 to establish appro-priate safety and health practices and determi
7、ne the applica-bility of regulatory limitations prior to use.1.5 This guide is applicable only at sites where chemical(organic and inorganic) wastes are a concern and is notintended for use at radioactive or mixed (chemical and radio-active) waste sites.1.6 The values stated in either SI units or in
8、ch-pound unitsare to be regarded as standard. Within the text, the inch-poundunits are shown in brackets. The values stated in each systemare not equivalents, therefore, each system must be usedindependently of the other.2. Referenced Documents2.1 ASTM Standards:3C 150 Specification for Portland Cem
9、entD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 2488 Practice for Description and Identification of Soils(Visual-Manual Procedure)D 3441 Test Method for Deep, Quasi-Static, Cone andFriction-Cone Penetration Tests of SoilD 5088 Practice for Decontamination of Field EquipmentUsed at
10、Nonradioactive Waste SitesD 5092 Practice for Design and Installation of GroundWater Monitoring Wells in AquifersD 5730 Guide to Site Characterization for EnvironmentalPurposesD 5778 Test Method for Performing Electronic FrictionCone and Piezocone Penetration Testing of SoilsD 6001 Guide for Direct
11、Push Water Sampling for Geoen-vironmental Investigations3. Terminology3.1 DefinitionsThe definitions of terms in this guide are inaccordance with Terminology D 653. Terms that are notincluded in Terminology D 653 are described as follows.3.2 Definitions of Terms Specific to This Standard:3.2.1 basel
12、ine, na set of zero load readings, expressed interms of apparent resistance, that are used as reference valuesduring performance of testing and calibration.3.2.2 bentonite, nthe common name for drilling fluidadditives and well construction products consisting mostly ofnaturally occurring sodium mont
13、morillonite. Some bentoniteproducts have chemical additives that may affect water qualityanalyses.3.2.3 cone, nthe conical point of a cone penetrometer onwhich the end bearing component of penetration resistance isdeveloped.1This guide is under the jurisdiction of ASTM Committee D18 on Soil and Rock
14、and is the direct responsibility of Subcommittee D18.21 on Ground Water andVadose Zone Investigations.Current edition approved Dec. 10, 1996. Published June 1997.2The boldface numbers in parentheses refer to the list of references at the end ofthis guide.3For referenced ASTM standards, visit the AST
15、M website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unite
16、d States.3.2.4 cone resistance, qc, n the end bearing component ofpenetration resistance.3.2.5 cone sounding, na series of penetration readingsperformed at one location over the entire depth when using acone penetrometer.3.2.6 electronic cone penetrometer, na friction cone pen-etrometer that uses fo
17、rce transducers, such as strain gage loadcells, built into a nontelescoping penetrometer tip for measur-ing within the penetrometer tip, the components of penetrationresistance.3.2.7 electronic piezocone penetrometer, n an electroniccone penetrometer equipped with a low-volume fluid chamber,porous e
18、lement, and pressure transducer for determination ofpore pressure at the porous element soil interface.3.2.8 end bearing resistance, nsame as cone resistance ortip resistance, qc.3.2.9 equilibrium pore water pressure, uo, nat rest waterpressure at depth of interest. Same as hydrostatic pressure.3.2.
19、10 excess pore water pressure, uuo, nthe differencebetween pore pressure measured as the penetratoin occurs, u,and estimated equilibrium pore water pressure, uo. Excess porepressure can be either positive or negative.3.2.11 friction ratio, Rf, n the ratio of friction sleeveresistance, f, to cone res
20、istance, qc, measured with the middleof the friction sleeve at the same depth as the cone point. It isusually expressed as a percentage.3.2.12 friction reducer, na narrow local protuberance onthe outside of the push rod surface, placed at a certain distanceabove the penetrometer tip, which is provid
21、ed to reduce thetotal side friction on the push rods and allow for greaterpenetration depths for a given push capacity.3.2.13 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 divi
22、ded byits surface area.3.2.14 friction sleeve, nan isolated cylindrical sleevesection on a penetrometer tip upon which the friction compo-nent of penetration resistance develops.3.2.15 local friction, nsame as friction sleeve resistance.3.2.16 penetrometer, nan apparatus consisting of a seriesof cyl
23、indrical push rods with a terminal body (end section)called the penetrometer tip and measuring devices for deter-mination of the components of penetration resistance.3.2.17 penetrometer tip, nthe terminal body (end section)of the penetrometer which contains the active elements thatsense the componen
24、ts of penetration resistance.3.2.18 piezocone, nsame as electronic piezocone pen-etrometer.3.2.19 piezocone pore pressure, u, nfluid pressure mea-sured using the piezocone penetration test.3.2.20 push rods, nthe thick walled tubes or rods used toadvance the penetrometer tip.3.2.21 sleeve friction or
25、 resistance, n same as frictionsleeve resistance, f.3.2.22 stratigraphy, na classification of soil behavior typethat categorizes soils of lateral continuity (4).3.3 Acronyms:Acronyms:3.3.1 CPTCone Penetration Test.3.3.2 PPTuPiezocone Penetration Test.3.3.3 ECPElectronic Cone Penetrometer (used when
26、re-ferring to the cone penetrometer).4. Significance and Use4.1 Environmental site characterization projects almost al-ways require information regarding subsurface soil stratigra-phy. Soil stratigraphy often is determined by various drillingprocedures and bore logs. Although drilling is very accura
27、teand useful, the electronic cone penetrometer test may be faster,less expensive, and provide greater resolution, and does notgenerate contaminated cuttings that may present other disposalproblems (2,3,4,5). Investigators may obtain soil samples fromadjacent borings for correlation purposes, but pri
28、or informationor experience in the same area may preclude the need forborings (1).4.2 The electronic cone penetration test is an in situ inves-tigation method involving:4.2.1 Pushing an electronically instrumented probe into theground (see Fig. 1 for a diagram of a typical cone penetrom-eter). The p
29、osition of the pore pressure element may vary.4.2.2 Recording force resistances, such as tip resistance,local friction, and sometimes pore pressure.4.2.3 Data interpretation.4.2.4 The most common use of the interpreted data isstratigraphy. Several charts are available. A typical CPTstratigraphic cha
30、rt is shown in Fig. 2 (1). The first step indetermining the extent and motion of contaminants is todetermine the subsurface stratigraphy. Since the contaminantswill migrate with ground water flowing through the morepermeable strata, it is impossible to characterize an environ-mental site without val
31、id stratigraphy. Cone penetrometer datahas been used as a stratigraphic tool for many years. The porepressure channel of the cone can be used to determine the depthto the water table or to locate perched water zones.4.2.5 When attempting to retrieve a soil gas or watersample, it is advantageous to k
32、now where the bearing zones(permeable zones) are located. Although soil gas and water canbe retrieved from on-bearing zones such as clays, the length oftime required usually makes it impractical. Soil gas and watersamples can be retrieved much faster from bearing zones, suchas sands. The cone penetr
33、ometer tip and friction data generallycan identify and locate the bearing zones and nonbearing zonesless than a foot thick. Since the test is run at a constant rate, thepore pressure data can often identify layers less than 20 mmthick.4.2.6 The electronic cone penetrometer test is used in avariety o
34、f soil types. Lightweight equipment with reactionweights of less than 10 tons generally are limited to soils withrelatively small grain sizes. Typical depths obtained are 20 to40 m, but depths to over 70 m with heavier equipmentweighing 20 tons or more are not uncommon. Since penetra-tion is a direc
35、t result of vertical forces and does not includerotation or drilling, it cannot be utilized in rock or heavilycemented soils. Depth capabilities are a function of manyfactors including:4.2.6.1 The force resistance on the tip,4.2.6.2 The friction along the push rods,4.2.6.3 The force and reaction wei
36、ght available,D 6067 96 (2003)24.2.6.4 Rod support provided by the soil, and4.2.6.5 Large grained materials causing nonvertical deflec-tion or unacceptable tool wear.4.2.7 Depth is always site dependent. Local experience isdesirable.4.3 Pore Pressure Data:4.3.1 The pore pressure data often is used i
37、n environmentalsite characterization projects to identify thin soil layers thatwill either be aquifers or aquitards. The pore pressure channeloften can detect these thin layers even if they are less than 20mm thick.4.3.2 Pore pressure data also is used to provide an indicationof relative hydraulic c
38、onductivity. Excess pore pressure isgenerated during an electronic cone penetrometer test. Gener-ally, high excess pore pressure indicates the presence ofaquitards, and low excess pore pressure indicates the presenceof aquifers. This is not always the case, however. For example,some silty sands and
39、over-consolidated soils generate negativepore pressures if monitored above the shoulder of the cone tip.See Fig. 2. The balance of the data, therefore, also must beevaluated.4.3.3 In general, since the ground water flows primarilythrough sands and not clays, modeling the flow through thesands is mos
40、t critical. The pore pressure data also can bemonitored with the sounding halted. This is called a porepressure dissipation test. A rapidly dissipating pore pressureindicates the presence of an aquifer while a very slowdissipation indicates the presence of an aquitard.4.3.4 A pore pressure decay in
41、a sand is almost instanta-neous. The permeability (hydraulic conductivity), therefore, isvery difficult to measure in a sand with a cone penetrometer. Asa result, the cone penetrometer is not used very often formeasuring the permeability of sands in environmental applica-tions.4.3.5 A thorough study
42、 of ground water flow also includesdetermining where the water cannot flow. Cone penetrometerFIG. 1 Electronic Cone PenetrometerD 6067 96 (2003)3pore pressure dissipation tests can be used very effectively tostudy the permeability of aquitards.4.3.6 The pore pressure data also can be used to estimat
43、e thedepth to the water table or identify perched water zones. Thisis accomplished by allowing the pressure to equilibrate andthen subtract the appropriate head pressure. Due to excess porepressures being generated, typical pore pressure transducersare configured to measure pressures up to 3.5 MPa 5
44、00 psi.Since transducer accuracy is a function of maximum range, thisprovides a relative depth to water level accuracy of about 6150mm. Better accuracy can be achieved if the operator allowssufficient time for the transducer to dissipate the heat generatedwhile penetrating dry soil above the water t
45、able. Lowerpressure transducers are sometimes used just for the purpose ofdetermining the depth to the water table more accurately. Forexample, a 175-KPa 25-psi transducer would provide accu-racy that is better than 10 mm. Caution must be used, however,to prevent these transducers from being damaged
46、 due to aquick rise in excess pressure.4.4 For a complete description of a typical geotechnicalelectronic cone penetrometer test, see Test Method D 5778.4.5 This guide tests the soil in situ. Soil samples are notobtained. The interpretation of the results from this guideprovides estimates of the typ
47、es of soil penetrated. Investigatorsmay obtain soil samples from adjacent borings for correlationpurposes, but prior information or experience in the same areamay preclude the need for borings.4.6 Certain subsurface conditions may prevent cone pen-etration. Penetration is not possible in hard rock a
48、nd usuallynot possible in softer rocks, such as claystones and shales.Coarse particles, such as gravels, cobbles, and boulders may bedifficult to penetrate or cause damage to the cone or push rods.Cemented soil zones may be difficult to penetrate depending onthe strength and thickness of the layers.
49、 If layers are presentwhich prevent direct push from the surface, rotary or percus-sion drilling methods can be employed to advance a boringthrough impeding layers to reach testing zones.5. Apparatus5.1 Most apparatus required is discussed in Test MethodD 5778. When using the electronic cone penetrometer test forenvironmental site characterization purposes, however, otheritems often are necessary.5.2 Safety EquipmentEnvironmental site characterizationoften involves exposure to potentially hazardous substances.Detection equipment to determine oxygen con
