ASTM D4546-2003 Standard Test Methods for One-Dimensional Swell or Settlement Potential of Cohesive Soils《粘性土的单维膨胀或沉降趋势的标准试验方法》.pdf

《ASTM D4546-2003 Standard Test Methods for One-Dimensional Swell or Settlement Potential of Cohesive Soils《粘性土的单维膨胀或沉降趋势的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM D4546-2003 Standard Test Methods for One-Dimensional Swell or Settlement Potential of Cohesive Soils《粘性土的单维膨胀或沉降趋势的标准试验方法》.pdf（7页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D 4546 03Standard Test Methods forOne-Dimensional Swell or Settlement Potential of CohesiveSoils1This standard is issued under the fixed designation D 4546; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l

2、ast 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 These test methods cover three alternative laboratorymethods for determining the magnitude of swell or settlementof

3、relatively undisturbed or compacted cohesive soil.NOTE 1Refer to Section 5 to determine the best method for aparticular application.1.2 The test methods can be used to determine (a) themagnitude of swell or settlement under known vertical (axial)pressure, or (b) the magnitude of vertical pressure ne

4、eded tomaintain no volume change of laterally constrained, axiallyloaded specimens.1.3 The values stated in SI units are to be regarded as thestandard. The values stated in inch-pound units are approxi-mate.1.4 All observed and calculated values shall conform to theguidelines for significant digits

5、and rounding established inPractive D 6026.1.4.1 The method used to specify how data are collected,calculated, or recorded in this standard is not directly related tothe accuracy to which the data can be applied in design or otheruses, or both. How one applies the results obtained using thisstandard

6、 is beyond its scope.1.5 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 determine the applica-bility of regulatory limitations prior t

7、o use.2. Referenced Documents2.1 ASTM Standards:D 422 Test Method for Particle-Size Analysis of Soils2D 653 Terminology Relating to Soil, Rock, and ContainedFluids2D 698 Test Method for Laboratory Compaction Character-istics of Soil Using Standard Effort (12.400 ft-lbf/ft3(600kN-m/m3)2D 854 Test Met

8、hod for Specific Gravity of Soils2D 1557 Test Method for Laboratory Compaction Character-istics of Soils Using Modified Effort (56.000 ft-lbf/ft3(2.700 kN-m/m3)2D 1587 Practice for Thin-Walled Tube Sampling of Soils2D 2216 Test Method for Laboratory Determination of Water(Moisture) Content of Soil a

9、nd Rock2D 2435 Test Method for One-Dimensional ConsolidationProperties of Soils2D 3550 Practice for Ring-Lined Barrel Sampling of Soils2D 3740 Practice for Minimum Requirements for AgenciesEngaged In the Testing and/or Inspection of Soil and Rockas Used In Engineering Design and Construction2D 3877

10、Test Methods for One-Dimensional Expansion,Shrinkage, and Uplift Pressure of Soil-Lime Mixtures2D 4220 Practices for Preserving and Transporting SoilSamples2D 4318 Test Method for Liquid Limit, Plastic Limit, andPlasticity Index of Soils2D 6026 Practice for Using Significant Digits in Geotechni-cal

11、Data23. Terminology3.1 DefinitionsRefer to Terminology D 653 for standarddefinitions of terms.3.2 Definitions of Terms Specific to This Standard:3.2.1 heave (L)increase in vertical height, D h,ofacolumn of in situ soil of height h following absorption of water.3.2.2 percent heave or settlement, %inc

12、rease or decreasein the ratio of the change in vertical height, D h, to the originalheight of a column of in situ soil; h 3 100 or D h/ h 3 100.3.2.3 settlement, Ldecrease in vertical height, D h,ofacolumn of in situ soil of height h.3.2.4 swell, Lincrease in elevation or dilation of soilcolumn foll

13、owing absorption of water.3.2.5 free swell, %percent heave, D h/h 3 100, followingabsorption of water at the seating pressure sse.1These test methods are under the jurisdiction of ASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.05 on StructuralProperties of S

14、oils.Current edition approved Jan. 10, 2003. Published February 2003. Originallyapproved in 1985. Last previous edition approved in 1996 as D 4546 96.2Annual Book of ASTM Standards, Vol. 04.08.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr H

15、arbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.6 primary swell, Lan arbitrary short-term swell usu-ally characterized as being completed at the intersection of thetangent of reverse curvature to the curve of a dimensionalchange-logarithm of time plot with the tangent t

16、o the straightline portion representing long-term or secondary swell (Fig. 1).3.2.7 secondary swell, Lan arbitrary long-term swell usu-ally characterized as the linear portion of a dimensionalchange-logarithm of time plot following completion of short-term or primary swell (Fig. 1).3.2.8 swell index

17、slope of the rebound pressure - void ratiocurve on a semi-log plot.3.2.9 swell pressure, FL2(1) a pressure which preventsthe specimen from swelling as obtained in Method C, or (2)that pressure which is required to return the specimen back toits original state (void ratio, height) after swelling in M

18、ethod Aor B.NOTE 2Swell pressures by Method C corrected for specimen distur-bance may be similar to or slightly greater than those by Method A.4. Summary of Test Methods4.1 The following three alternative test methods require thata soil specimen be restrained laterally and loaded axially in aconsoli

19、dometer with access to free water.4.1.1 Method AThe specimen is inundated and allowed toswell vertically at the seating pressure (pressure of at least 1kPa (20 lbf/ft2) applied by the weight of the top porous stoneand load plate) until primary swell is complete. The specimenis loaded after primary s

20、well has occurred until its initial voidratio/height is obtained.4.1.2 Method BA vertical pressure exceeding the seatingpressure is applied to the specimen before placement of freewater into the consolidometer. The magnitude of verticalpressure is usually equivalent to the in situ vertical overburde

21、npressure or structural loading, or both, but may vary dependingon application of the test results. The specimen is given accessto free water. This may result in swell, swell then contraction,contraction, or contraction then swell. The amount of swell orsettlement is measured at the applied pressure

22、 after movementis negligible.4.1.3 Method CThe specimen is maintained at constantheight by adjustments in vertical pressure after the specimen isinundated in free water to obtain swell pressure. A consolida-tion test is subsequently performed in accordance with TestMethod D 2435. Rebound data is use

23、d to estimate potentialheave.5. Significance and Use5.1 The relative swell/settlement potential of soil deter-mined from these test methods can be used to developestimates of heave or settlement for given final moisture andloading conditions. The initial water content and void ratioshould be represe

24、ntative of the in situ soil immediately prior toconstruction. Selection of test method, loading, and inundationsequences should, as closely as possible, simulate any con-struction and post-construction wetting and drying effects andchanges in loading conditions.5.2 Soils containing montmorillonites

25、(Smectite) are likelyto have a significant potential for swell and are commonlytested by these test methods.NOTE 3Montmorillonites with divalent cations usually swell less thanwith monovalent cations. It is useful to know the type of cation as well asthe cation exchange capacity of montmorillonite.5

26、.3 Laboratory-prepared test specimens should duplicate thein situ soil or field-compacted soil conditions as closely aspossible because relatively small variations in unit weight andwater content can significantly alter the measured heave andswell pressure. Differences in soil fabric of the compacte

27、dspecimens, such as obtained by kneading or static compaction,could also have a significant impact on the swell/settlementbehavior of cohesive soils.5.4 These test methods are applicable to undisturbed test orremolded specimens, or both, as follows:5.4.1 Method AThis test method measures (a) the fre

28、eswell, (b) percent heave for vertical confining pressures up tothe swell pressure, and (c) the swell pressure.5.4.2 Method BThis test method measures (a) the percentheave or settlement for vertical pressure usually equivalent tothe estimated in situ vertical overburden and other verticalpressure up

29、 to the swell pressure, and ( b) the swell pressure.5.4.3 Method CThis test method measures (a) the swellpressure, (b) preconsolidation pressure, and (c) percent heaveor settlement within the range of applied vertical pressures.NOTE 4Methods A and C have produced estimates of heave consis-tent with

30、observed heave. Method B may lead to estimates of heave lessthan observed heave. Method A has not been recommended for evaluationof swell pressure and consolidation parameters for settlement estimatesbecause sorption of water under practically no restraint may disturb thesoil structure.NOTE 5Notwith

31、standing the statement on precision and bias con-tained in this standard: The precision of this test method is dependent onthe competence of the personnel performing the test and the suitability ofthe equipment and facilities used. Agencies which meet the criteria ofPractice D 3740 are generally con

32、sidered capable of competent andobjective testing. Users of this test method are cautioned that compliancewith Practice D 3740 does not in itself assure reliable testing. Reliabletesting depends on several factors; Practice D 3740 provides a means ofevaluating some of these factors.6. Interferences6

33、.1 Estimates of the swell and settlement of soil determinedby these test methods are often of key importance in design offloor slabs on grade and evaluation of their performance.FIG. 1 Time - Swell CurveD4546032However, when using these estimates it is recognized that swellparameters determined from

34、 these test methods for the purposeof estimating in situ heave of foundations and compacted soilsmay not be representative of many field conditions because:6.1.1 Lateral swell and lateral confining pressure are notsimulated.6.1.2 Swell in the field usually occurs under constantoverburden pressure, d

35、epending on the availability of water.Swell in the laboratory is evaluated by observing changes involume due to changes in applied pressure while the specimenis inundated with water. Method B is designed to avoid thislimitation.6.1.3 Rates of swell indicated by swell tests are not alwaysreliable ind

36、icators of field rates of heave due to fissures in thein situ soil mass and inadequate simulation of the actualavailability of water to the soil. The actual availability of waterto the foundation may be cyclic, intermittent, or depend onin-place situations, such as pervious soil-filled trenches andb

37、roken water and drain lines.6.1.4 Secondary or long-term swell may be significant forsome soils and should be added to primary swell.6.1.5 Chemical content of the inundating water affectsvolume changes and swell pressure; that is, field water con-taining large concentrations of calcium ions will pro

38、duce lessswelling than field water containing large concentrations ofsodium ions or even rain water.6.1.6 Disturbance of naturally occurring soil samplesgreatly diminishes the meaningfulness of the results.7. Apparatus and Materials7.1 ConsolidometerThe apparatus shall comply with therequirements of

39、 Test Method D 2435. The apparatus shall becapable of exerting a pressure on the specimen of (1) at least200 % of the maximum anticipated design pressure, or (2) thepressure required to maintain the original specimen heightwhen the specimen is inundated (Method C), whichever isgreatest.7.1.1 Consoli

40、dometer rigidity influences the observed swell,particularly with Method C. Therefore, consolidometers ofhigh rigidity should be used with Method C (see Test MethodD 2435).NOTE 6Small increases in soil volume can significantly relieve swellpressures. Therefore, variations in displacements that occur

41、during deter-mination of swell pressures by Method C should be as small as possibleto reduce the magnitude of correction required in 13.2.5. The measure-ments, especially swell pressure measurements, should be based oncorrections for compression of members.7.2 Porous StonesThe stones shall be smooth

42、 ground andfine enough to minimize intrusion of soil into the stones if filterpaper is not used and shall reduce false displacements causedby seating of the specimen against the surface of porous stones(Note 7). Such displacements may be significant, especially ifdisplacements and applied vertical p

43、ressures are small.7.2.1 Porous stones shall be air dry.7.2.2 Porous stones shall fit close to the consolidometer ringto avoid extrusion or punching at high vertical pressures.Suitable stone dimensions are described in 5.3 of Test MethodD 2435.NOTE 7A suitable pore size is 10 m if filter paper is no

44、t used. Filterpaper is not recommended because of its high compressibility and shouldnot be used when measuring the swell/settlement of stiff clays and whenmeasuring swell pressure by Method C.7.3 Plastic Membrane, Aluminum Foil, or Moist PaperTowel, a loose fitting cover to enclose the specimen, ri

45、ng, andporous stones prior to inundating the specimen, used tominimize evaporation from the specimen.8. Sampling of Naturally Occurring Soils8.1 Disturbance of the soil sample from which specimensare to be obtained greatly diminishes the meaningfulness ofresults and should be minimized. Practice D 1

46、587 and PracticeD 3550 cover procedures and apparatus that may be used toobtain satisfactory undisturbed samples.8.2 Storage in sampling tubes is not recommended forswelling soils even though stress relief may be minimal. Theinfluence of rust and penetration of drilling fluid or free waterinto the s

47、ample may adversely influence laboratory test results.Water and oxygen from the sample could cause the formationof rust within the tube which could result in the sampleadhering to the tube. Therefore, sampling tubes should bebrass, stainless steel, or galvanized or lacquered inside toinhibit corrosi

48、on in accordance with Practice D 1587.8.3 If samples are to be stored prior to testing, they shouldbe extruded from the sampling tubes as quickly as possibleafter sampling and thoroughly sealed to minimize further stressrelief and moisture loss. The sample should be extruded fromthe sampling tube in

49、 the same direction as sampled, tominimize further sample disturbance. If the sample cannot beextruded from the tubes immediately, they should be handledand shipped in accordance with Practices D 4220, Group D.8.4 Prior to sealing in storage containers, samples extrudedfrom tubes that were obtained with slurry drilling techniquesshould be wiped clean to remove drilling fluid adhering to thesurface of the sample. An outer layer of 3 to 6 mm (0.1 to 0.3in.) should be trimmed from the cylindrical surface of thesamples so that moisture or the slurry will not pen