1、A1,級配良好的粗砂/礫/碎石+無塑性結(jié)合料A2,細粒含量W35%且不屬于A1、A3的粒狀材料，一般指級配不良的粒狀材料.A3,細砂，不含細粒成份A4,無塑性或中等塑性粉質(zhì)土，細粒含量三75%A5,高液限粉質(zhì)土，細粒含量三75%A6,塑性黏土A7,高液限的塑性黏土技術(shù)人員培訓(xùn)和認證程序ClassificationofSoilandSoil-AggregateMixturesForHighwayConstructionPurposesAASHTOM-145-91(2000)(Modified)用于公路施工目的的土壤及土壤集料混合物的分類AASHTOM-145-91(2000)(修改過的)This

2、practicedescribesaprocedureforclassifyingsoilsintosevengroupsbasedonlaboratorydeterminationofparticle-sizedistribution,liquidlimit,andplasticityindex.Thegroupclassificationshouldbeusefulindeterminingtherelativequalityofthesoilmaterialforuseinembankments,subgrades,andbackfills.Fordetaileddesignofimpo

3、rtantstructures,additionaldataconcerningstrengthorperformancecharacteristicsofthesoilunderfieldconditionswillusuallyberequired.本實踐描述了用于根據(jù)顆粒尺寸分布、液限及塑性指數(shù)把土壤分為七個組的步驟。該分組對于確定用于路堤、路基和回填的土壤材料相對質(zhì)量是有用的。對于重要構(gòu)筑物的詳細設(shè)計,通常要求關(guān)于野外條件下土壤的強度或性能特征的補充資料。Modification:DeterminationofGroupIndexwillnotbeapartofcertificatio

4、n,buttaughtasausefultoolformoreaccuratedeterminationofsoilclassification.修改：確定分組指數(shù)不是鑒定的一部分,但作為更精確地確定土壤分類的有用的工具而講授。KeyElements:要素：Determinesieveanalysis.DeterminesieveanalysisusingAASHTOT-11andAASHTOT-27testprocedures(Note1).The2.00mm(No.10)sieve,425-pm(No.40)sieve,and75-pm(No.200)sievemustbeincluded

5、todeterminetheparticlesizedistributionasabasisforclassification.確定篩析使用AASHTOT-11和AASHTOT-27測試程序確定篩析。作為分類的基礎(chǔ)，2mm(10號)篩、425gm(40號篩)和75|dm(200號)篩必須被包括以確定顆粒尺寸分布。Determinetheliquidlimit.DeterminetheliquidlimitofthematerialusingAASHTOT-89testprocedures.2.確定液限使用AASHTOT-89測試程序來確定材料的液限。Determinetheplasticlim

6、it.DeterminetheplasticlimitandplasticityindexofthematerialusingAASHTOT-90testprocedures.3.確定塑限使用AASHTOT-90測試程序來確定材料的塑限和塑性指數(shù)。Determineclassificationofmaterial.UsingthetestlimitsshowninTable1ofAASHTOM-145,maketheclassificationofthematerial.Ifamoredetailedclassificationisdesired,afurthersubdivisionofth

7、egroupsmaybemadeusingTable2ofAASHTOM-145(3.1).Withrequiredtestdataavailable,proceedfromlefttorightinTable1orTable2andthecorrectgroupwillbefoundbyprocessofelimination(3.2).Thefirstgroupfromtheleftintowhichthetestdatawillfitisthecorrectclassification(3.2).4.確定材料類別使用AASHTOM-145表1所列測試界限來進行材料分類。如果要求更精確的材

8、料分類，可以使用AASHTOM-145(3.1)表2來進行進一步的細分。用現(xiàn)有的所需測試資料在表1或表2中從左到右進行，正確的組將通過排除法被找到。從左邊開始測試資料第一個符合的組就是正確的分類。Reportclassification.Alllimitingtestvaluesareshownaswholenumbers.Iffractionalnumbersappearontestreports,converttothenearestwholenumberforpurposesofclassification(3.2).5.分類報告所有測試界限值都以整數(shù)表示。如果在測試報告中出現(xiàn)小數(shù)，為分

9、類目的要轉(zhuǎn)換為最接近的整數(shù)。DESCRIPTIONOFSOILCLASSIFICATIONGROUPS:土壤分組描述：SoilFractions:AccordingtotheAASHTOsystem,soilsaredividedintotwomajorgroupsasshowninTable1ofAASHTOM-145.Thesearethegranularmaterialswith35percentorlesspassingthe75-pm(No.200)sieve(5.1)andthesilt-claymaterialswithmorethan35percentpassingthe75-

10、pm(No.200)sieve(5.2).Moreover,fivesoilfractionsarerecognizedandoftenusedinworddescriptionsofamaterial.Thesefivefractionsaredefinedasfollows:土壤粒級：根據(jù)AASHTO系統(tǒng)，土壤劃分為如AASHTOM-145表1所示的兩個主要群組。它們是有著通過75-gm(200號)篩(5.1)少于等于35%的粒狀材料和有著通過75-gm(200號)篩(5.2)部分大于35%的粉-黏土材料。此外，5個粒級被確認并常常用于描述材料的詞中。這五個粒級定義如下：Bouldersa

11、ndCobblesmaterialretainedonthe75mm(3in.)sieve.Theyshouldbeexcludedfromtheportionofasampletowhichtheclassificationisapplied,butthepercentageofsuchmaterialshouldberecorded(4.1.5).漂石與卵石一留在75mm篩上的材料。它們應(yīng)被從分類所使用樣品中排除，但這樣的材料的百分比應(yīng)被記錄4.1.5)。Gravelmaterialspassingsievewith75mm(3in.)squareopeningsandretainedon

12、the2.0mm(No.10)sieve(4.1.1).礫石一通過75mm方形開口并保留在2mm篩(10號)上的材料4.1.1)。CoarseSandmaterialspassingthe2.0mm(No.10)sieveandretainedonthe425-m(No.40)sieve(4.1.2).粗砂一通過2mm篩并保留在425+m(40號)篩之上的材料4.1.2)。FineSandmaterialspassingthe425-m(No.40)sieveandretainedonthe75-pm(No.200)sieve(4.1.3).細砂一通過425小篩并保留在75-m(200號)篩上

13、的材料4.1.3)。CombinedSiltandClaymaterialpassingthe75-pm(No.200)sieve.heordsiltyisappliedtoafinematerialhavingaPlasticityIndexof10orless,andtheterm“clayey”isappliedtofinematerialhavingaPIofmorethan10(4.1.6).合并粉土與黏土一通過75-m篩的材料“粉質(zhì)”這個詞用于塑性指數(shù)小于等于0的細粒材料。而“黏質(zhì)”這個詞用于塑性指數(shù)大于10的材料(4.1.6)。GRANULARMATERIALS:粒狀材料：Gro

14、upA-1:Well-gradedmixturesofstonefragmentsorgravelrangingfromcoarsetofinewithanon-plasticorslightlyplasticsoilbinder(5.1.1).However,thisgroupalsoincludescoarsematerialswithoutsoilbinder.組A-1：由一系列含無塑性或輕微塑性土結(jié)合料的從粗到細的石頭碎塊或礫石所組成的級配良好的混合物(5.11)，然而，該組也包括不含土結(jié)合料的粗粒材料。SubgroupA-1-a:Materialsconsistingpredomin

15、antlyofstonefragmentsorgravel,eitherwithorwithoutawellgradedsoilbinder(5.1.1.1).亞組A-1-a：材料主要由含或不含級配良好土結(jié)合料的石頭碎塊或礫石組成.(5.1.1.1)。SubgroupA-1-b:Materialsconsistingpredominantlyofcoarsesandeitherwithorwithoutawell-gradedsoilbinder(5.1.1.2).亞組A-1-b：材料主要由含或不含良好級配土結(jié)合料的粗砂組成。GroupA-3:Materialconsistingofsands

16、deficientincoarsematerialandsoilbinder.Typicalisfinebeachsandorfinedesertblowsand,withoutsiltorclayfinesorwithaverysmallamountofnon-plasticsilt.Thisgroupalsoincludesstreamdepositedmixturesofpoorlygradedfinesandandlimitedamountsofcoarsesandandgravel(5.1.2).Thesesoilsmakesuitablesubgradesforalltypesof

17、pavementswhenconfinedanddamp.Theyaresubjecttoerosionandhavebeenknowntopumpandblowunderrigidpavements.(Information:Theycanbecompactedbyvibratory,pneumatic-tired,andsteel-wheeledrollersbutnotwithasheepsfootroller.)組A-3：由缺乏粗粒材料和土結(jié)合料的砂所組成的材料。典型者如海灘砂或沙漠飛砂，不含粉土或黏土細?；蚝浅Ｉ倭康臒o塑性粉土。該組也包括河流沉積的不良級配細砂與數(shù)量有限的粗砂和礫石

18、的混合物(5.1.2)。密閉和防潮的情況下其可以作為各種類型路面的基床。眾所周知其在剛性路面下其易于受沖刷并噴涌。(信息：它們可以通過振動式、氣胎式以及鋼輪式壓路機來碾壓，但不用羊足碾。)GroupA-2:ThisgroupincludesawidevarietyofgranularmaterialsthatareborderlinebetweenthematerialsfallinginGroupsA-1andA-3andsilt-claymaterialsofGroupsA-4,A-5,A-6andA-7.Itincludesallmaterialscontaining35percento

19、rlesspassingthe75-pm(No.200)sievethatcannotbeclassifiedasA-1orA-3(5.1.3).組A-2：該組包括組A-1、組A-3及粉-黏土材料的組A-4、A-5、A-6和A-7范圍之外的各種各樣的“粒狀材料，它包括了所有通過75-gm(200號)篩含量小于等于35%的不能被歸于A-1或A-3(5.1.3)的材料。SubgroupsA-2-4andA-2-5:Includevariousgranularmaterialscontaining35percentorlesspassingthe75-pm(No.200)sieve,andwitht

20、hatportionpassing425-pm(No.40)sievehavingthecharacteristicsoftheA-4andA-5groups.ThesegroupsincludesuchmaterialsasgravelandcoarsesandwithsiltcontentsorPlasticityIndexesinexcessofthelimitationsofGroupA-1,andfinesandwithnon-plasticsiltcontentinexcessofthelimitationsofGroupA-3(5.1.3.1).亞組A-2-4和A-2-5包括通過

21、75-gm(200號)篩含量小于等于35%、通過425-pm(40號)篩的部分具有組A-4和組A-5特征的各種各樣的材料。這些組包括粉土成份或塑性指數(shù)超出組A-1限值的礫石和粗砂，以及含有無塑性粉土成份超出組A-3限值的的細砂SubgroupsA-2-6andA-2-7:IncludematerialssimilartothosedescribeunderSubgroupsA-2-4andA-2-5,exceptthatthefineportioncontainsplasticclayhavingthecharacteristicsoftheA-6orA-7group(5.1.3.2).亞組A

22、-2-6和A-2-7：包括與亞組A-2-4和A-2-5下所描述的那些相似的材料，但是細粒部分所含的塑性黏土具有組A-2-6或A-2-7的特征。A-2soilsaregivenapoorerratingthanA-1soilsbecauseofinferiorbinder,poorgrading,oracombinationofthetwo.Dependingonthecharacterandamountofbinder,A-2soilsmaybecomesoftduringwetweatherandlooseanddustyindryweatherwhenusedasaroadsurface.

23、If,however,theyareprotectedfromtheseextremechangesinmoisturecontent,theymaybequitestable.TheA-2-4andA-2-5soilsaresatisfactoryasbasematerialswhenproperlycompactedanddrained.A-2-6andA-2-7soilswithlowpercentagesofminus75-pm(no.200)sievematerialareclassifiedasgoodbases,whereasthesesamesoilswithhighperce

24、ntagesofminus75-pm(No.200)sieveandPIsof10orhigherarequestionableasabasematerial.Frequently,theA-2soilsareemployedasacovermaterialforveryplasticsubgrades.因為劣等的結(jié)合料、差的級配或兩者的組合，A-2土壤與A-1土壤相比評分較差。根據(jù)結(jié)合料的特征和數(shù)量，A-2土壤當做為路面時在雨天可能變軟，而在干天變得松散多塵。然而，如果避免含水量極端的變化，其可以很穩(wěn)定。A-2-4和A-2-5土壤在適當?shù)乇荒雺汉团潘畷r可滿足被作為基料的要求。有著低百分比的通

25、過75-gm(200號)篩含量的A-2-6和A-2-7土被歸作好的基料，而塑性指數(shù)大于等于10者作為基料是有疑問的。A-2土壤常常被當作塑性很強基床的覆蓋材料。SILT-CLAYMATERIALS:粉土-黏土材料GroupA-4:Thetypicalmaterialofthisgroupisanon-plasticormoderatelyplasticsiltysoilusuallyhaving75percentormorepassingthe75pm(No.200)sieve.Thegroupincludesalsomixturesoffinesiltysoilandupto64percen

26、tofsandandgravelretainedonthe75-pm(No.200)sieve(5.2.1).Thesepredominantlysiltysoilsarequitecommoninoccurrence.Theirtexturevariesfromsandyloamstosiltyandclayeyloams.Withtheproperamountofmoisturepresent,theymayperformwellasapavementcomponent.However,theyfrequentlyhaveanaffinityforwaterandwillswellandl

27、osemuchoftheirstabilityunlessproperlycompactedanddrained.Moreover,theyaresubjecttofrostheave.Thesesoilsdonotdrainreadilyandmayabsorbwaterbycapillaryactionwithresultinglossinstrength.Thesiltyloamsareoftendifficulttocompactproperly.Carefulfieldcontrolofmoisturecontentandpneumatictiredrollersarenormall

28、yrequiredforpropercompaction.組A-4：該組的典型材料是無塑性或中等塑性粉質(zhì)土，通常通過75-pm(200號)篩含量大于等于75%。該組也包括細的粉質(zhì)土和最多64%的留在75-gm（200號）篩的砂和礫石組成的混合物（5.2.1）。這些占優(yōu)勢的粉質(zhì)土壤很常見。從亞砂土到亞黏土其特征發(fā)生變化。其作為路面成分時在正確的含水量下可以表現(xiàn)良好。然而它們常常具有親水性并會膨脹而失去穩(wěn)定性，除非被適當?shù)啬雺汉团潘?。此外其易于凍脹。這些土不易排水并可通過毛細作用吸水從而導(dǎo)致喪失強度。亞砂土常常難以被適當碾壓。為了適當碾壓，通常需要現(xiàn)場細心的含水量控制和氣胎式壓路機。GroupA-

29、5:ThetypicalmaterialofthisgroupissimilartothatdescribedunderGroupA-4,exceptthatitisusuallyofdiatomaceousormicaceouscharacterandmaybehighlyelasticasindicatedbythehighliquidlimit（5.2.2）.ThesesoilsdonotoccuraswidelyastheA-4soils.Theyarenormallyelasticorresilientinboththedampandsemi-dryconditions.Theyar

30、esubjecttofrostheave,erosion,andlossofstabilityifnotproperlydrained.Sincethesesoilsdonotdrainreadilyandmayabsorbwaterbycapillaryactionwithresultinglossinstrength.Carefulcontrolofmoisturecontentisnormallyrequiredforpropercompaction.組A-5：該組的典型材料類似于組A-4所描述的，此外當顯示出高液限時通常具有硅藻的或云母質(zhì)特征且可以是高度彈性的（5.2.2）。這些土壤不

31、象A-4土壤那樣廣泛出現(xiàn)，在潮濕或半干狀態(tài)下都常具有彈性。如未恰當排水則易于凍脹、沖蝕并喪失穩(wěn)定性。這些土不易排水并可通過毛細作用吸水從而導(dǎo)致喪失強度。為了適當碾壓，通常需要仔細控制含水量。GroupA-6:Thetypicalmaterialofthisgroupisplasticclaysoilusuallyhaving75percentormorepassingthe75-pm（No.200）sieve.Thegroupincludesalsomixturesoffineclayeysoilandupto64percentofsandandgravelretainedonthe75-pm

32、（No.200）sieve.Materialsofthisgroupusuallyhavehighvolumechangebetweenwetanddrystates（5.2.3）.Thesesoilsarequitecommoninoccurrenceandarewidelyusedinfills.Whenmoisturecontentisproperlycontrolled,theycompactquitereadilywitheitherasheepsfootorpneumatictiredroller.Theyhavehighdrystrengthbutlosemuchofthisst

33、rengthuponabsorbingwater.TheA-6soilswillcompresswhenwetandshrinkandswellwithchangesinmoisturecontent.Whenplacedintheshouldersadjacenttothepavement,theytendtoshrinkawayfromthepavementedgeupondryingandtherebyprovideanaccessroutetotheundersideofthepavementforsurfacewater.TheA-6soilsdonotdrainreadilyandmayabsorbwaterbycapillaryactionwithresultinglossinstrength.組A-6：該組的典型材料是塑性的黏土，通常具有通過75-gm（200號）篩含量大于等于75%。該組也包括該組也包括細的黏質(zhì)土壤和最多64%的留在75-g