《土的工程分类标准》

Foreword

AccordingtotherequirementsofDocumentJIANBIAO[2004]No.67issuedbytheMinistryofConstruction-"NoticeonPrintingandDistributing'theDevelopmentandRevisionPlanofNationalEngineerConstructionStandardsin2004'",thisstandardwasrevisedbyNanjingHydraulicResearch

InstitutebasedonGBJ145-90StandardforClassificationofSoils.

Thisstandardincludesfivechapters.Itsmaintechnicalcontentsinclude:generalprovisions;terms,symbolsanddesignations;basicrequirements;soilclassification;simplifiedsoilidentification,classificationanddescription.Anappendixisalsoprovided.

Themainrevisionsmadeinthisstandardareasfollows:thecontextsrelevanttospecialsoilsareremoved.Terms,symbolsanddesignationsareadded.Appendix1forbasicdesignationsisremoved;onesubgroupfractionsareincreasedforgravel,twosubgroupfraetionsareincreasedforsand;theplasticitychartwiththeliquidlimitscorrespondingto10mmdepthoffall-conepenetrationisremoved,alongwithitsrelatedcontexts;andAppendixA:Systemblockdiagramforengineeringclassificationofsoilsisadded.

TheMinistryofConstructionisinchargeoftheadministrationofthisstandard.GeneralInstituteofWaterResourcesandHydropowerPlanningandDesignofMinistryofWaterResourcesisresponsiblefortheroutinemanagementofthisstandard.ExplanationofthetechnicalconentisundertakenbyNanjingHydraulicResearchInstitute.Alltherelevantorganizationsareencouragedtoobtainexperienceinusingthisstandard,andalsokindlyrequestedtosubmitcommentsandadvices,whenevernecessary,totheNanjingHydraulicResearchInstitute(Address223GuangzhouRoad,Nanjing,210029,China)forfuturerevision.

ChiefDevelopmentOrganizations,Co-DevelopmentOrganizationsandChiefDraftersofthisStardand:

ChiefDevelopmentOrganizations:

NanjingHydraulicResearchInstitute

Co-DeyelopmentOrganizations:

ChinaAcademyofBuildingResearch

ComprehensiveInstituteofGeotechnicalInvestigationandSurveying

BeijingGeotechnicalInstitute

AcademyofRailwaySciences

ResearchInstituteofHighwayofMinistryofCommunications

GeneralBuildingResearchInstituteofChinaMetallurgyGroup

MechanicalIndustrySurveyandDesignInstitute

ChinaInstituteofWaterResourcesandHydropowerResearch

YangtzeRiverScientificResearchInstitute

Xi'anUniversityofTechnology

JilinUniversity

ChiefDrafters:

FANMingqiaoTENGYanjingWUWeiLIUYanhuaLUOMeiyun

WANGYuanXINHongboZHANGWeiWENYanfengGONGBiweiHUZaiqiangWANGQingTIANXichunandWANGFang

Contents

1Generalprovisions (

1)

2Terms,symbolsanddesignations (

2)

2.1Tem (

2)

2.2Symbols (

2)

2.3Designations (

3)

3Basicstipulations (

5)

4Soilclassification (

7)

5Simplifiedidentification,classification,anddescriptionofsoils (

9)

5.1SimplifiedIdentificationmethods (

9)

5.2Identificationandclassifcation (

10)

5.3Soildescription (

10)

AppendixASystemblockdiagramforengineeringclassificationofsoils (

12)

Explanationofwordinginthisstandard (

14)

1Generalprovisions

1.0.1Thisstandardisformulatedtounifytheengineeringclassficationofsoilstofacilitatethequalitative

evaluationofsoilcharacteristics.

1.0.2Thisstandardisapplicabletobasicclassificationofsoils.Aspecializedstandardforsoilclassificationmaybeformulatedincompliancewiththisstandardtomeettheprofessionaldemandsofrelevantindustries.

1.0.3Inadditiontotherequirementsofthisstandard,theindextestingforsoilclassificationshallalsocomplywiththesespecifiedintherelevantcurrentnationalstandards

·2·

2Terms,symbolsanddesignations

2.1Terms

2.1.1grainsize

Theminimumdiameterofsieveopeningthroughwhichsoilgraincouldpass,orthediameterof

equivalentspherewhichhasthesamevelocityofsoilgrainsettleinstillwater.

2.1.2grainsizedistributioncurve

Acurverepresentsthemasspercentageofsoilgrainfinerthanaspecificgrainsize.

2.1.3constrainedgrainsize

Thegrainsizecorrespondingto60%fineronthecumulativegrain-sizedistributioncurveofsoil.2.1.4effectivegrainsize

Thegrainsizecorrespondingto10%fineronthecumulativegrain-sizedistributioncurveofsoil.

2.1.5fraction

Agroupofsoilparticleswithacertainrangeofgrainsizedistribution.

2.1.6coefficientofuniformity

Thecoefficientindicatingthedegreeofuniformityofgrainsizes(

2.1.7coefficientofcurvature

Thecoefficientindicatingtheshapeofgrain-sizedistributioncurve.

2.1.8gradation

Themassproportionofeachspecialgrain-sizegrouptothewhole.

2.1.9liquidlimit

Thewatercontemtboundarybetweenliquidandplasticstatesoffine-grainedsoil.2.1.10plasticlimit

Thewatercontentboundarybetweenplasticandsemi-solidstatesoffine-grainedsoil.2.1.11plasticityindex

Numericaldifferencebetweentheliquidandplasticlimitsoffine-grainedsoil.

2.1.12plasticitychart

Achartforclassifyingfine-grainedsoils,inwhichtheplasticityindexIp(ordinate)isplottedagainsttheliquidlimitw.(abscissa).

2.1.13organicsoil

ClaysorsiltswithcertainorganiccontentOm(5%≤0m<10%),specialodor(smells)andhigh

compressibility.

2.1.14organo-soil

ClaysorsiltswithhighorganiccontentOm(Om≥10%),specialodor(smells)andhigh

compressibility.

2.2Symbols

C.—coefficientofcurvature;

C₀—coefficientofuniformity;

·3·

d—grainsize;d—constrained

grainsize;

d₀—effectivegrainsize;

Ip—elasticityindex;

wi—liquidlimit;

wp—plasticlimit;

Om—organiccontent.

2.3Designations

2.3.1Basicdesignations:

B—Boulder;

C—Clay;

Cb—Cobble;

F—Finesoil;

G—Gravel;

H—Highliquidlimit;

L—Lowliquidlimit;

M—Silt;

O—Organicsoil;

P—Poorly-graded;

S—Sand;

SI—Mixtureofverycoarsesoils;

W—Well-graded.

2.3.2Groupdesignations

BSI—Boulderswithfinersoils;

CbSI—Cobbleswithfinersoils;

CH—Highliquidlimitclay(Fatclay);

CHG—Gravellyclaywithhighliquidlimit(Gravellyfatclay);

CHO—Organicclaywithhighliquidlimit(Organicfatclay);

CHS—Sandyclaywithhighliquidlimit(Sandyfatclay);

CL—Lowliquidlimitclay(Leanclay);

CLG—Gravellyclaywithlowliquidlimit(Gravellyleanclay);

CLO—Organicclaywithlowliquidlimit(Organicleanclay);

CLS—Sandyclaywithlowliquidlimit(Sandyleanclay);

GC—Clayeygravel;

GF—Gravelwithfines;

GM—Siltygravel;

GP—Poorly-gradedgravel;

GW—Well-gradedgravel;

MH—Highliquidlimitsilt(Elasticsilt);

MHG—Gravellysiltwithhighliquidlimit(Gravellyelasticsilt);

MHO—Organicsiltwithhighliquidlimit(Organicelasticsilt);

MHS—Sandysiltwithhighliquidlimit(Sandyelasticsilt);

ML—Lowliquidlimitsilt(Silt);

MLG—Gravellysiltwithlowliquidlimit(Gravellysilt);

MLO—Organicsiltwithlowliquidlimit(Organicsilt);

MLS—Sandysiltwithlowliquidlimit(Sandysilt);

SC—Clayeysand;

SF—Sandwithfines;

SIB—Mixtureofbouldersandfinersoils;

SICb—Mixtureofcobblesandfinersoils;

SM—Siltysand;

SP—Poorly-gradedsand;

SW—Well-gradedsand.

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3Basicstipulations

3.0.1Classificationofasoilshallbebasedonthefollowingindices:

1Thegrain-sizedistributionandcharacteristicsofthesoil.

2Theconsistencysindicesofthesoil:liquidlimit(wi),plasticlimit(w),andplasticityindex(I₁).

3Theorganiccontentofthesoil.

3.0.2ThefractionofasoilshallbedividedaccordingtoitsgrainsizerangeasspecifiedinTable3.0.2.Table3.0.2Divisionoffraction

Fraction

Component

Grain-sizerange(representedbydiameterd,mm)

Verycoarsegrain

Boulder(Blockstone)

d>200

Cobble(Brokenstone)

60<d≤200

Coarsegrain

Gravel

Coarse

20<d≤60

Medium

5<d≤20

Fine

2<d≤5

Sand

Coarse

0.5<d≤2

Medium

0.25<d≤0.5

Fine

0.075<d≤0.25

Finegram

Silt

0.005<d≤0.075

Clay

d≤0.005

3.0.3ThegradationcharacteristicsofsoilshallbedeterminedaccordingtothecoefficientofuniformityCandthecoefficientofcurvatureC.asfollows:

1ThecoefficientofuniformityC.shallbecalculatedbythefollowingequation:

2ThecoefficientofcurvatureCshallbecalculatedbythefollowingequation:

(3.0.3-1)

(3.0.3-2)

wheredoisthegrainsizecorrespondingto30%fineronthecumulativegrain-sizedistributioncurveof

thesoil.

3.0.4Soilscanbeclassifiedintoverycoarse-grained,coarse-grained,andfine-grainedtypesbasedontherelativecontentofdifferentfractionsandshallcomplywiththestipulationsasfollows:

1Verycoarse-grainedsoilsshallbeclassifiedbasedonfraction.

2Coarse-grainedsoilsshallbeclassifiedbasedonfraction,gradation,contentoffine-grainedsoil.

3Fine-grainedsoilsshallbeclassifiedbasedontheplasticitychart,typeofcoarse-grainedcomponentandorganiccontentcontained.

3.0.5Fine-grainedsoilsshallbeclassifiedwiththeplasticitychart(Figure3.0.5).

plasticityindex,Ip

Liquidlimit,wr(%)

Figure3.0.5Plasricitychart

Note:1TheabscissaofFigure3.0.5denotestheliquidlimit(cr)andtheordinatedenotestheplasticityindex(Ip)ofthesoil.

2TheliquidlimitinFigure3.0.5isthewatercontentmeasuredwithCasagrandepercussion-cupapparatus,orthewatercontent

correspondingtoa17mmpenetrationofafallingconewithamassof76gandatipangleof30°.

3TheareabetweenthedottedlinesinFigure3ta.5fthefransionzonefromclaytosit.

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·7·

4Soilclassification

4.0.1Classificationofverycoarse-grainedsoilsshallmeetthestipulationsspecifiedinTable4.0.1.Table4.0.1Classificationofverycoarse-grainedsoils

Soilcategory

Fractioncontent

Groupdesignation

Name

Verycoarse-grainedsoils

Verycoarsefractioncontent>75%

Bouldercontent>cobblecontent

B

Boulder(Blockstone)

Bouldercontent≤cobblecontent

Cb

Cobble(Rubble)

Verycoarsesoils

mixedwithfiner

soils

50%<Verycoarse

ractioncontent≤75%

Bouldercontentcobblecontent

BSI

Boulder(Blockstone)withfinersoil

Bouldereontent

cobblecontent

CbSI

Cobble(Rubble)withfinersoils

Finersoilsmixed

withverycoarse

soils

15%<Verycoarse

fractioncontent≤50%

Bouldercontent>cobblecontent

SIB

Mixtureoffinersoilsandboulders(Blockstones)

Bouldercontent≤cobblecontent

SICb

Mixtureoffinersoilsand

cobbles(Rubbles)

Note:Finersoilsmixedwithyerycoarsesoilsmaybefurthersubdividedbasedonthecontentofcoarsegrainsorfines.

4.0.2Ifthecontentofverycoarse-grainedfractionis15%orless,thesoilsamplemaybeclassifiedbasedonthecorrespondingstipulationsforcoarsegrainsorfineswithoutconsiderationofverycoarse-grainedfraction.Whenverycoarse-grainedfractionhasaninfluenceontheoverallpropertiesofsoil,itshouldbetreatedasgravelfraction.

4.0.3Classifythesoilascoarse-grainedsoils,ifthecoarse-grainedfractioncontentisgreaterthan50%,anditsclassificationshallmeetthefollowingstipulations:

1Classifythesoilasgravel,ifgravelfractioncontentisgreaterthansandcontent;

2Classifythesoilassand,ifgravelfractioncontentisequaltoorlessthansandcontent.4.0.4TheclassificationofgravelsshallmeetthestipulationsspecifiedinTable4.0.4.

Table4.0.4Classificationofgravelsoils

Soilcategory

Fractionconten

Groupdesignation

Name

Gravel

Finesfraction<5%

C≥5and1≤C≤3

GW

Well-gradedgravel

C<5or(C<lorC>3)

GP

Poorly-gradedgravel

Gravelwithfines

5%≤Finesfraction<15%

GF

Gravelwithfines

Finesgravel

15%≤Finesfraction<50%

Finesclassifiedasclay*

GC

Clayeygravel

Finesclassifiedassilt**

GM

Siltygravel

Note:*Thesiltgrainedcontentoffinegrainedfractionis50%orless;

**Thesiltgrainedcontentoffinegrainedfractionisgreaterthan50%.

·8·

4.0.5ClassificationofsandsshallmeetthestipulationsspecifiedinTable4.0.5.

Table4.0.5Classificationofsandsoils

Soilcategory

Fractioncontent

Groupsymbol

Name

Sand

Finesfraction<5%

C≥5and1≤C≤3

C<5or(C<1orC>3)

SW

Well-gradedsand

SP

Poorly-gradedsand

Sandwithfines

5%≤Finesfraction<15%

SF

Sandwithfines

Finessand

15%≤Fines

fraction<50%

Finesclassifiedasclay*

SC

Clayeysand

Finesclassifiedassilt**

SM

Siltysand

Note:*Thesiltgrainedcontentoffinegrainedfractionis50%orless;

**Thesiltgrainedcontentoffinegrainedfractionisgreaterthan50%.

4.0.6Classifythesoilasfine-grainedsoils,ifthefinesfraetioncontentisgreaterthan50%.4.0.7Fine-grainedsoilshallbeclassifiedaccordingtothefollowingstipulations.

1Classifythesoilasfines,ifthecoarse-grainedfractuioncontentis25%orless.

2Classifythesoilassandyorgravellyfines,ifthecoarse-grainedfractioncontentisgreaterthan

25%but50%orless.

3Classifythesoilasorganicsoil,iftheorganiccontentislessthan10%but5%ormore.4.0.8TheclassificationoffinesshallmeeithestipulationsspecifiedinTable4.0.8.

Table4.0.8Classificationoffines

PositionofplasticindicesofsoilinplasticitychartFigure3.0.5

Groupdesignation

Name

I≥0.73(w₁.-20)

andIp≥7

w₁≥50%

CH

Highliquidlimitclay(Fatclay)

w₁<50%

CL

Lowliquidlimitclay

(Leanclay)

1<0.73[w,-20

orl4

w₁≥50%

MH

Highliquidlimitsilt

(Elasticsilt)

wi<50%

ML

Lowliquidlimitsilt

(Slit)

Note:Soilsinthetransitionzonefromclaytosilt(CL-ML)maybefurthersubdividedinaccordancewiththetypesofadjacentsoillayers.4.0.9Fineswithcoarsegrainsshallbeclassifiedaccordingtothepositionofplasticindicesofsoilinplasticitychartandtypesofcoarsegrains,andtheirclassificationshallmeetthefollowingstipulations:

1ClassifythesoilasgravellyfinesandaddsymbolGattheendofthedesignationoffines,ifthecontentofgravelincoarsegrainsisgreaterthanthatofsand.

2ClassifythesoilassandyfinesandaddsymbolSattheendofthedesignationoffines,ifthecontentofgravelincoarsegrainsislessthanorequaltothatofsand.

4.0.10TheclassificationoforganicsoilsshallmeetthestipulationsspecifiedinTable4.0.8,andaddsymbolOattheendofthecorrespondingsoildesignation.

4.0.11Ifthesoilindexequalsthecorrespondinglimitvalueasdefined,thesoilmaybeclassifiedbasedonasafetyprincipleforpracticaluse.

4.0.12SoilsmaybeclassifiedaccordingtoAppendixA.

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5Simplifiedidentification,classificationanddescriptionofsoils

5.1Simplifiedidentificationmethods

5.1.1Visualidentification:spreadadispersedair-driedsampleintoathinlayer,andclassifythesoilaccordingtotheproportionofverycoarse,coarse,andfinegrains.

5.1.2Drystrengthtest:pinchasmallpieceofsoilintoapat.Afterdryinginair,crumb,breakoff,andtwistitwithfingers.Thefollowingdistinctionsshallbemadebasedonthefingerpressure:

1Highdrystrength:difficulttocrumborbreakoff.

2Mediumdrystrength:slightforcetocrumborbreakoff.

3Lowdrystrength:easytocrumbortwistintopowder,

Note:Whenthesoilcontainscarbonates,ironoxides,andotherconnponentsthatmayincreasesoildrystrength,wetsamplesshouldbeusedforhand-twisttesttoassessandcheckitsdrystrength.

5.1.3Hand-twisttest:pinchasmallpieceofslightly-wetorhard-plasticsoilinhand,andpinchitintosliceswiththumbandindexfingers.Thefollowingdistinctionsshallbemadebasedonhandfeelingand

smoothnessofsoilslices:

1Highplasticity:creamyfeeling,nosandyfeeling,andsmoothSurface,

2Mediumplasticity:slightlycreamyfeeling,sandyfeeling,andstightlysmoothsurface.3Lowplasticity:slightlyyiseousfeeling,strongsandyfeeling,androughsurface.

5.1.4Thread-rollingtest:evenlykneadapieceofsoilwithwatercontentslightlyhigherthantheplasticlimitinhands,thenrollitintoathreadonpalm.Thefollowingdistinctionsshallbemadebasedontheminimumdiameterthatthesoilthreadcouldbeformedwithoutcrumbling:

1Highplasticity:thediameterlessthan1mm.

2Mediumplasticity:thediameterbetween1mmand3mm.

3Lowplasticity:thediametergreaterthan3mm.

5.1.5Toughnesstest:evenlykneadapieceofsoilwithawatercontentslightlyhigherthantheplasticlimitinhandsevenly,thenrollitintoathreadwithadiameterof3mmonpalm.Thefollowing

distinctionsshallbemadebasedonwhetherthethreadcanberefoldedandrerolled:

1Hightoughness:beingshapedintoapat,rolledintoathread,andrefoldedintoapatwithoutcrumblingpieces.

2Mediumtoughness:beingshapedintoapatandnoteasilycrumbled.

3Lowtoughness:beinghardlyornottobeshapedintoapat,andpronetocrumblingbyslightor

nopinching.

5.1.6Dilatancytest:moldthesoilinsoftorliquidplasticstateintoaball,shakeitrepeatedlyonthepalm,andstrikethesideofthepalmagainstbytheotherpalmseveraltimes.Freewaterseepsoutfromthesoil,andtheballsurfaceshowsluster.Pinchthesoilballwithtwofingers.Afterreleasing,thewaterisreabsorbedandthelusterdisappears.Thefollowingdistinctionsshallbemadebasedonthereactionspeedsofwaterseepageandabsorption:

1Rapidreaction:quickwaterseepageandabsorption.

2Mediumreaction:medium-speedwaterseepageandabsorption.

·10·

3Slowreaction:slowwaterseepageandabsorption.

4Noreaction:nowaterseepageandabsorption.

5.2Identificationandclassification

5.2.1Verycoarse-grainedandcoarse-grainedsoilsmaybeclassifiedandnamedaccordingtostipulationssetoutin4.0.1to4.0.6basedonvisualresults.

5.2.2Fine-grainedsoilsmaybeclassifiedandnamedbasedonresultsofdrystrength,hand-twist,thread-rolling,toughness,anddilatancytestsaccordingtostipulationssetoutinTable5.2.2.

Table5.2.2Simplifiedclassificationoffine-grainedsoils

Drystrength

Hand-twisttest

Thread-rollingtest

Dilatancytest

Designation

Minimum

diameterofsoil

thread(mm)

Toughness

Low-medium

Mainlysilt,sandyfeeling,

slightlyviscous,medium

roughsurface,andnoluster

32

Low-medium

Quick-mediun

ML

Medium-high

Containingsandgraing

viscous,slightlycreamy

feeling;mediumsmooth

surface,slighulylustrous

2-1

Medium

Slow-no

CL

Medium-high

Richsilr,viscous,slightly

creamy/feeling,medium

smoothsurface,slightly

lustrous

2-1

Medium-high

slow-no

MH

High-veryhigh

Nosandyfeelings,highly

viscous,stronglycreamy

feeling,smoothsurface,

lustrous

<1

High

No

CH

Note:Foralltypesofsoilslistedinthetablethataregrayordarkincolorandhaveaspecialsmell,thesymbolOshallbeaddedattheendofcorrespondingsoildesignation,e.g.,MLO,CLO,MHO,andCHO.

5.2.3Organicmattersinsoilsareincompletelydecomposedanimalorplantremainsandamorphoussubstance.Theymaybeidentifiedbyvisualobservation,handtouchingorsmelling.Generally,organicmattersaregreyordark,withspecialodor,elasticityandspongefeeling.

5.3Soildescription

5.3.1Thedescriptionofsoilsshouldincludethefollowingitems:

1Verycoarse-grainedandcoarse-grainedsoils:popularnameandlocalname;maximumgrainsize;degreeofweatheringofparticles;masspercentageofverycoarsegrains,gravelgrains,andsandgrains;shapesofverycoarseorcoarsegrains(round,sub-round,angularorsub-angular);mineralcompositionofsoilparticles;colorandorganicmatter;naturaldensity;typesoffines(clayorsilt)contained;symbolandnameofasoilorsoillayer.

·11·

2Fine-grainedsoils:popularnameandlocalname;maximumgrainsize;masspercentageofvery

coarsegrains,gravelgrains,andsandgrains;naturaldensity;colorandorganicmatterofthesoilinwetstate;humidityofthesoil(dry,wet,verywetorsaturated);consistencyofthesoil(liquidplastic,soft

plastic,plastic,hard

soils.

plastic,hard);plasticity

ofthesoil(high,medium,orlow);symbolandnameof

·12·

AppendixASystemblockdiagramforengineeringclassificationofsoils

Very-coarsefractioncontent>75%

Boulder(B)

Bouldercontent>cobblecontent

Cobble(Cb)

Bouldercontent≤cobblecontent

Verycoarse-grainedsoils

Very-coarsefraction

content>15%

50%<Verycoarsefraction

content≤75%

Boulderwithfinersoils(BSI)

Boulderc