ASTM D6635-2001(2007) Standard Test Method for Performing the Flat Plate Dilatometer《平板式膨胀计使用的标准试验方法》.pdf

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1、Designation: D 6635 01 (Reapproved 2007)Standard Test Method forPerforming the Flat Plate Dilatometer1This standard is issued under the fixed designation D 6635; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi

2、sion. 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 This test method describes an in-situ penetration plusexpansion test. The test is initiated by forcing the steel, flatplate, d

3、ilatometer blade2, with its sharp cutting edge, into asoil. Each test consists of an increment of penetration, gener-ally vertical, followed by the expansion of a flat, circular,metallic membrane into the surrounding soil. The test providesinformation about the soils in-situ stratigraphy, stress,str

4、ength, compressibility, and pore-water pressure for use in thedesign of earthworks and foundations.1.2 This method includes specific requirements for thepreliminary reduction of dilatometer test data. It does notspecify how to assess or use soil properties for engineeringdesign.1.3 This method appli

5、es best to those sands, silts, clays, andorganic soils that can be readily penetrated with the dilatometerblade, preferably using static push (see 4.2). Test results forsoils containing primarily gravel-sized particles and larger maynot be useful without additional research.1.4 This method is not ap

6、plicable to soils that cannot bepenetrated by the dilatometer2blade without causing signifi-cant damage to the blade or its membrane.1.5 The American Society for Testing and Materials takesno position respecting the validity of any patent rights assertedin connection with any item mentioned in this

7、standard. Usersof this standard are expressly advised that determination of thevalidity of any such patent rights, and the risk of infringementof such rights, are entirely their own responsibility.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its us

8、e. It is theresponsibility of the 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:3D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 1586 Test Me

9、thod for Penetration Test and Split-BarrelSampling of SoilsD 2435 Test Methods for One-Dimensional ConsolidationProperties of Soils Using Incremental LoadingD 3441 Test Method for Mechanical Cone Penetration Testsof SoilD 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/

10、or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 5778 Test Method for Performing Electronic FrictionCone and Piezocone Penetration Testing of Soils3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 A-pressurethe gage gas pressure against the insideof

11、the membrane when the center of the membrane has liftedabove its support and moved laterally 0.05-mm (tolerance+0.02, -0.00 mm) into the soil surrounding the blade.3.1.2 B-pressurethe gage gas pressure against the insideof the membrane when the center of the membrane has liftedabove its support and

12、moved laterally 1.10-mm (6 0.03 mm)into the soil surrounding the blade.3.1.3 C-pressureThe gage gas pressure against the insideof the membrane when the center of the membrane returns tothe A-pressure position during a controlled, gradual deflationfollowing the B-pressure.3.1.4 DMTabbreviation for th

13、e flat plate dilatometer testas described herein.3.1.5 DMT soundingthe entire sequence of dilatometertests and results along a vertical line of penetration in the soil.3.1.6 DMT testthe complete procedure of penetration,membrane inflation and then deflation for a single test depthusing the fiat plat

14、e dilatometer.3.1.7 DAthe gage gas pressure inside the membrane(corrected for Zm) required to overcome the stiffness of the1This 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

15、 Soil Evaluations.Current edition approved July 1, 2007. Published August 2007. Originallyapproved in 2001. Last previous edition approved in 2001 as D 6635 01.2The dilatometer is covered by a patent held by Dr. Silvano Marchetti, ViaBracciano 38, 00189, Roma, Italy. Interested parties are invited t

16、o submit informa-tion regarding the identification of acceptable alternatives to this patented item to theCommittee on Standards, ASTM Headquarters, 100 Barr Harbor Drive, WestConshohocken, PA 194282959. Your comments will receive careful considerationat the meeting of the responsible technical comm

17、ittee, which you may attend.3For 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 Document Summary page onthe ASTM website.1Copyright ASTM International, 10

18、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.membrane and move it inward to a center-expansion of 0.05mm (a negative gage or suction pressure, but recorded aspositive) with only ambient atmospheric pressure acting exter-nally.3.1.8 DBthe gage gas pressure inside

19、the membrane(corrected for Zm) required to overcome the stiffness of themembrane and move it outward to a center-expansion of 1.10mm against only the ambient atmospheric pressure.3.1.9 EDthe dilatometer modulus, based on linear elastictheory, and the primary index used in the correlation for thecons

20、trained and Youngs moduli (see Section 9).3.1.10 Gmbulk specific gravity = moist soil unit weightdivided by the unit weight of water.3.1.11 IDthe dimensionless dilatometer material index,used to identify soil type and delineate stratigraphy (seeSection 9).3.1.12 KDthe dimensionless dilatometer horiz

21、ontal stressindex, the primary index used in the correlation for in-situhorizontal stress, overconsolidation ratio, and undrained shearstrength in cohesive soils. KDis similar to the at-rest coefficientof earth pressure except that it includes blade penetrationeffects.3.1.13 membranea thin, flexible

22、, 60-mm diameter circu-lar piece of sheet metal (usually stainless steel), fixed aroundits edges, that mounts on one side of the dilatometer blade andwhich, as a result of an applied internal gas pressure, expandsinto the soil in an approximate spherical shape along an axisperpendicular to the plane

23、 of the blade.3.1.14 Pthe total push, or thrust force required to advanceonly the dilatometer blade to its test depth, measured at its testdepth and exclusive of soil or other friction along the pushrods.3.1.15 p0the A-pressure reading, corrected for Zm, the DAmembrane stiffness at 0.05-mm expansion

24、, and the 0.05-mmexpansion itself, to estimate the total soil stress acting normalto the membrane immediately before its expansion into the soil(0.00-mm expansion, see Section 9).3.1.16 p1the B-pressure reading corrected for Zmand theDB membrane stiffness at 1.10-mm expansion to give the totalsoil s

25、tress acting normal to the membrane at 1.10-mm mem-brane expansion (see Section 9).3.1.17 p2The C-pressure reading corrected for Zmand theDA membrane stiffness at 0.05-mm expansion and used toestimate pore-water pressure (see 9.3).3.1.18 s8vvertical effective stress at the center of themembrane befo

26、re the insertion of the DMT blade.3.1.19 svtotal vertical stress at the center of the mem-brane before the insertion of the DMT blade, generallycalculated from unit weights estimated using the DMT results.3.1.20 u0the pore-water pressure acting at the center ofthe membrane before the insertion of th

27、e DMT blade (oftenassumed as hydrostatic below the water table surface).3.1.21 Zmthe gage pressure deviation from zero whenvented to atmospheric pressure (an offset used to correctpressure readings to the true gage pressure).4. Summary of Test Method4.1 A dilatometer test (DMT) consists of forcing t

28、hedilatometer blade into the soil, with the membrane facing thehorizontal direction, to a desired test penetration, measuringthe thrust to accomplish this penetration and then using gaspressure to expand a circular steel membrane located on oneside of the blade. The operator measures and records the

29、pressure required to produce expansion of the membrane intothe soil at two preset deflections. The operator then deflates themembrane, possibly recording an optional third measurement,advances the blade the desired penetration increment andrepeats the test. Each test sequence typically requires abou

30、t 2minutes.Adilatometer sounding consists of the results from allthe tests at one location presented in a fashion indicatingvariation with depth.4.2 The operator may advance the blade using either aquasi-static push force or dynamic impact from a hammer, withquasi-static push preferred. A record of

31、the penetration resis-tance (thrust force or blows per penetration increment) isdesirable both for control of the penetration and later analyses.NOTE 1In soils sensitive to impact and vibrations, such as medium toloose sands or sensitive clays, dynamic insertion methods can significantlychange the t

32、est results compared to those obtained using a quasi-staticpush. In general, structurally sensitive soils will appear more compressiblewhen tested using dynamic insertion methods. In such cases check fordynamic effects and, if important, calibrate and adjust test interpretationsaccordingly.4.3 The p

33、enetration increment typically used in a dilatom-eter test (DMT) sounding varies from 0.15 to 0.30 m (0.5 to 1.0ft). Most soundings are performed vertically and this TestMethod requires that the membrane face the horizontal direc-tion. Testing below impenetrable layers will require preboringand supp

34、orting (if required) a borehole with a diameter of atleast 100 mm (4 in.).4.4 The operator performs a membrane calibration beforeand after each DMT sounding.4.5 The field data is then interpreted to obtain profiles ofthose engineering soil properties of interest over the depthrange of the DMT soundi

35、ng.5. Significance and Use5.1 Soundings performed using this test method provide adetailed record of dilatometer results which are useful forevaluation of site stratigraphy, homogeneity, depth to firmlayers, voids or cavities, and other discontinuities. The pen-etration resistance and subsequent mem

36、brane expansion areused for soil classification and correlation with engineeringproperties of soils. When properly performed at suitable sites,the test provides a rapid means of characterizing subsurfaceconditions.5.2 The DMT test provides measurements of penetrationresistance, lateral stress, defor

37、mation modulus and pore-waterpressure (in sands). However, the in-situ soil properties areaffected by the penetration of the blade. Therefore, publishedcorrelations are used to estimate soil properties for the designand construction of earthworks and foundations for structures,and to predict the beh

38、avior of soils subjected to static ordynamic loads.5.3 This test method tests the soil in-situ and soil samplesare not obtained. However, the interpretation of the resultsfrom this test method does provide an estimate of the types ofsoil penetrated. Soil samples from parallel borings may beD 6635 01

39、 (2007)2obtained for correlation purposes, but prior information orexperience may preclude the need for borings.6. Apparatus6.1 The annotated Fig. 1 illustrates the major components ofthe DMT equipment, exclusive of that required to insert theblade. The dimensions, tolerances, deflections, etc. have

40、 beenset by the inventor, and holder of the dilatometer patent, S.Marchetti.6.1.1 Blade, (1), 96 mm wide (95 to 97 mm) and 15 mmthick (13.8 to 15 mm).6.1.2 Membrane, (2), 60 mm diameter.6.1.3 Control Unit, with a pressure readout system (3) thatcan vary in type, range, and sensitivity as required. G

41、ages withan accuracy better than14 percent of span are recommended.The unit shown has both low-range and high-range Bourdongages that are read manually. Older units have a singleBourdon gage, typically medium-range. The gages should beannually calibrated against a traceable standard, more often ifhe

42、avily used. The control unit also includes connections (5) fora pressure source, a pneumatic-electrical cable, and an electri-cal ground cable, and has valves to control gas flow and ventthe system (6).6.1.4 Calibration Syringe, (4) for determining the DA andDB membrane calibrations using the low-ra

43、nge Bourdon gage.Some control units have a separate low-range pressure gagewhich attaches to the control unit for determining the DA andDB membrane calibrations6.1.5 Pneumatic-Electrical Cable, (7) to transmit gas pres-sure and electrical continuity from the control unit to the blade.6.1.6 Ground Ca

44、ble, (8) to provide electrical continuitybetween the push rod system and the calibration unit.6.2 Insertion equipment is required to advance the blade tothe test depth. The blade may be pushed using the quasi-staticthrust of a drill rig or cone penetrometer rig (CPT, see TestMethod D 3441/D 5778), d

45、riven using a hammer such as in thestandard penetration test (SPT, see Test Method D 1586 andNote 1), or inserted using other suitable equipment. Drill rigsupport may be required to born through impenetrable soil orrock layers above the desired test depth.6.3 Push rods are required to transfer the t

46、hrust from thesurface insertion equipment and to carry the pneumatic-electrical cable from the surface control unit to the dilatometerblade. The rods are typically those used with the CPT (TestMethod D 3441/D 5778) or SPT (Test Method D 1586) equip-ment. Suitable adapters are required to attach the

47、blade to thebottom of the rod string and allow the cable to exit near the topof the rods. When testing from the bottom of a borehole, thecable may exit from the rod string some suitable distance abovethe blade and then be taped to the outside of the rods atappropriate intervals. The exposed cable sh

48、ould not be pinchedor allowed to penetrate the soil.6.4 A gas pressure tank with a suitable regulator and tubingto connect it to the control unit is required. The operator mayuse any nonflammable, noncorrosive, nontoxic gas as a pres-sure source. Dry nitrogen is recommended.6.5 A suitable load cell,

49、 just above the blade or at the top ofthe rods, is required to measure the thrust P applied during theblade penetration. Hydraulic ram pressure may also be used tomeasure thrust with proper correlation. Parasitic soil-rod fric-tion is generally insignificant in sands, but may be measuredduring upward withdrawal.7. Procedure7.1 Preparation for Testing and Calibration:7.1.1 Select for testing only blades that conform to themanufacturers internal tolerance adjustments and that are ingood visual external condition. The blade should have nodiscernible bend, defi