外文資料翻譯原文題目DESIGNANDEXECUTIONOFGROUNDINVESTIGATIONFOREARTHWORKS院系名稱專業(yè)班級(jí)土木0801學(xué)生姓名學(xué)號(hào)指導(dǎo)教師教師職稱副教授DESIGNANDEXECUTIONOFGROUNDINVESTIGATIONFOREARTHWORKSABSTRACTTHEDESIGNANDEXECUTIONOFGROUNDINVESTIGATIONWORKSFOREARTHWORKPROJECTSHASBECOMEINCREASINGLYIMPORTANTASTHEAVAILABILITYOFSUITABLEDISPOSALAREASBECOMESLIMITEDANDCOSTSOFIMPORTINGENGINEERINGFILLINCREASEANOUTLINEOFGROUNDINVESTIGATIONMETHODSWHICHCANAUGMENTTRADITIONALINVESTIGATIONMETHODSPARTICULARLYFORGLACIALTILL/BOULDERCLAYSOILSISPRESENTEDTHEISSUEOFGEOTECHNICALCERTIFICATIONISRAISEDANDRECOMMENDATIONSOUTLINEDONITSMERITSFORINCORPORATIONWITHGROUNDINVESTIGATIONSANDEARTHWORKS1INTRODUCTIONTHEINVESTIGATIONANDREUSEEVALUATIONOFMANYIRISHBOULDERCLAYSOILSPRESENTSDIFFICULTIESFORBOTHTHEGEOTECHNICALENGINEERANDTHEROADDESIGNENGINEERTHESEGLACIALTILLORBOULDERCLAYSOILSAREMAINLYOFLOWPLASTICITYANDHAVEPARTICLESIZESRANGINGFROMCLAYTOBOULDERSMOSTOFOURBOULDERCLAYSOILSCONTAINVARYINGPROPORTIONSOFSAND,GRAVEL,COBBLESANDBOULDERSINACLAYORSILTMATRIXTHEAMOUNTOFFINESGOVERNSTHEIRBEHAVIOURANDTHESILTCONTENTMAKESITVERYWEATHERSUSCEPTIBLEMOISTURECONTENTSCANBEHIGHLYVARIABLERANGINGFROMASLOWAS7FORTHEHARDGREYBLACKDUBLINBOULDERCLAYUPTO2025FORMIDLAND,SOUTHWESTANDNORTHWESTLIGHTGREYBOULDERCLAYDEPOSITSTHEABILITYOFBOULDERCLAYSOILSTOTAKEINFREEWATERISWELLESTABLISHEDANDPOORPLANNINGOFEARTHWORKSOFTENAMPLIFIESTHISTHEFINESOILCONSTITUENTSAREGENERALLYSENSITIVETOSMALLINCREASESINMOISTURECONTENTWHICHOFTENLEADTOLOSSINSTRENGTHANDRENDERTHESOILSUNSUITABLEFORREUSEASENGINEERINGFILLMANYOFOURBOULDERCLAYSOILSESPECIALLYTHOSEWITHINTERMEDIATETYPESILTSANDFINESANDMATRIXHAVEBEENREJECTEDATTHESELECTIONSTAGE,BUTGOODPLANNINGSHOWSTHATTHEYCANINFACTFULFILSPECIFICATIONREQUIREMENTSINTERMSOFCOMPACTIONANDSTRENGTHTHESELECTIONPROCESSSHOULDAIMTOMAXIMISETHEUSEOFLOCALLYAVAILABLESOILSANDWITHCAREFULEVALUATIONITISPOSSIBLETOUSEORINCORPORATEPOORORMARGINALSOILSWITHINFILLAREASANDEMBANKMENTSFILLMATERIALNEEDSTOBEPLACEDATAMOISTURECONTENTSUCHTHATITISNEITHERTOOWETTOBESTABLEANDTRAFFICABLEORTOODRYTOBEPROPERLYCOMPACTEDHIGHMOISTURECONTENT/LOWSTRENGTHBOULDERCLAYSOILSCANBESUITABLEFORUSEASFILLINLOWHEIGHTEMBANKMENTSIE2TO25MBUTNOTSUITABLEFORTRAFFICKINGBYEARTHWORKPLANTWITHOUTUSINGAGEOTEXTILESEPARATORANDGRANULARFILLCAPPINGLAYERHENCE,ITISVITALTHATTHEEARTHWORKSCONTRACTORFULLYUNDERSTANDSTHEHANDLINGPROPERTIESOFTHESOILS,ASFORMANYPROJECTSTHISISEFFECTIVELYGOVERNEDBYTHETRAFFICABILITYOFEARTHMOVINGEQUIPMENT2TRADITIONALGROUNDINVESTIGATIONMETHODSFORROADPROJECTS,APRINCIPALAIMOFTHEGROUNDINVESTIGATIONISTOCLASSIFYTHESUITABILITYOFTHESOILSINACCORDANCEWITHTABLE61FROMSERIES600OFTHENRASPECIFICATIONFORROADWORKSSRW,MARCH2000THEMAJORITYOFCURRENTGROUNDINVESTIGATIONSFORROADWORKSINCLUDESACOMBINATIONOFTHEFOLLOWINGTOGIVETHEREQUIREDGEOTECHNICALDATATRIALPITSCABLEPERCUSSIONBOREHOLESDYNAMICPROBINGROTARYCOREDRILLINGINSITUTESTINGSPT,VARIABLEHEADPERMEABILITYTESTS,GEOPHYSICALETCLABORATORYTESTINGTHEIMPORTANCEOFPHASINGTHEFIELDWORKOPERATIONSCANNOTBEOVERSTRESSED,PARTICULARLYWHENASSESSINGSOILSUITABILITYFROMDEEPCUTAREASCABLEPERCUSSIONBOREHOLESARENORMALLYSUNKTOADESIREDDEPTHORREFUSALWITHDISTURBEDANDUNDISTURBEDSAMPLESRECOVEREDAT100MINTERVALSORCHANGEOFSTRATAINMANYINSTANCES,CABLEPERCUSSIONBORINGISUNABLETOPENETRATETHROUGHVERYSTIFF,HARDBOULDERCLAYSOILSDUETOCOBBLE,BOULDEROBSTRUCTIONSSAMPLEDISTURBANCEINBOREHOLESSHOULDBEPREVENTEDANDLOSSOFFINESISCOMMON,INVARIABLYTHISLEADSTOINACCURATECLASSIFICATIONTRIALPITSARECONSIDEREDMOREAPPROPRIATEFORRECOVERINGAPPROPRIATESIZESAMPLESANDFOROBSERVINGTHEPROPORTIONOFCLASTSTOMATRIXANDSIZESOFCOBBLES,BOULDERSDETAILEDANDACCURATEFIELDDESCRIPTIONSARETHEREFOREVITALFORCUTAREASANDTRIALPITSPROVIDEANOPPORTUNITYTOEXAMINETHESOILSONALARGERSCALETHANBOREHOLESTRIALPITSALSOPROVIDEANINSIGHTONTRENCHSTABILITYANDTOOBSERVEWATERINGRESSANDITSEFFECTSASUITABLYEXPERIENCEDGEOTECHNICALENGINEERORENGINEERINGGEOLOGISTSHOULDSUPERVISETHETRIALPITTINGWORKSANDRECOVERYOFSAMPLESTHECHARACTERISTICSOFTHESOILSDURINGTRIALPITEXCAVATIONSHOULDBECLOSELYOBSERVEDASTHISPROVIDESINFORMATIONONSOILSENSITIVITY,ESPECIALLYIFWATERFROMGRANULARZONESMIGRATESINTOTHEFINEMATRIXMATERIALVERYOFTEN,THECONDITIONOFSOILONTHESIDESOFANEXCAVATIONPROVIDESAMOREACCURATEASSESSMENTOFITSINSITUCONDITION3SOILCLASSIFICATIONSOILDESCRIPTIONANDCLASSIFICATIONSHOULDBEUNDERTAKENINACCORDANCEWITHBS59301999ANDTESTEDINACCORDANCEWITHBS13771990THEENGINEERINGDESCRIPTIONOFASOILISBASEDONITSPARTICLESIZEGRADING,SUPPLEMENTEDBYPLASTICITYFORFINESOILSFORMANYOFOURGLACIALTILL,BOULDERCLAYSOILSIEMIXEDSOILSDIFFICULTIESARISEWITHDESCRIPTIONSANDASSESSINGENGINEERINGPERFORMANCETESTSASOUTLINEDPREVIOUSLY,IRISHBOULDERCLAYSUSUALLYCOMPRISEHIGHLYVARIABLEPROPORTIONSOFSANDS,GRAVELSANDCOBBLESINASILTORCLAYMATRIXLOWPLASTICITYSOILSWITHFINESCONTENTSOFAROUND10TO15OFTENPRESENTTHEMOSTDIFFICULTIESBS59301999NOWRECOGNISESTHESEDIFFICULTIESINDESCRIBINGMIXEDSOILSTHEFINESOILCONSTITUENTSWHICHGOVERNTHEENGINEERINGBEHAVIOURNOWTAKESPRIORITYOVERPARTICLESIZEAKEYPARAMETERWHICHISOFTENUNDERESTIMATEDINCLASSIFYINGANDUNDERSTANDINGTHESESOILSISPERMEABILITYKINSPECTIONOFTHEPARTICLESIZEGRADINGSWILLINDICATEMAGNITUDEOFPERMEABILITYWHERE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GIVENTOTHEIRENDUSEINMANYCASES,THESCHEDULEISPREPAREDBYAJUNIORENGINEERWHILETHESENIORDESIGNENGINEERWHOWILLPROBABLYDESIGNTHEEARTHWORKSWILLHAVENOREALINVOLVEMENTITISHIGHLIGHTEDTHATTHEENGINEERINGPERFORMANCETESTSAREEXPENSIVEANDOFLONGDURATIONEG5POINTCOMPACTIONWITHCBRMCVATEACHPOINTTAKESINEXCESSOFTWOWEEKSWHENCLASSIFICATIONTESTSMOISTURECONTENTS,PARTICLESIZEANALYSISANDATTERBERGLIMITSARECOMPLETEDTHENAMOREINCISIVEEVALUATIONCANBECARRIEDOUTONTHEDATAANDTHEENGINEERINGPERFORMANCETESTSSCHEDULEDIFMCVSAREPERFORMEDDURINGTRIALPITTINGTHENAGOODASSESSMENTOFTHESOILSUITABILITYCANBEIMMEDIATELYOBTAINED62DEEPTRIALPITSTHEEXCAVATIONOFDEEPTRIALPITSISOFTENPERCEIVEDASCUMBERSOMEANDDIFFICULTANDTHEREFORENOTCONSIDEREDAPPROPRIATEBYDESIGNENGINEERSEXCAVATIONOFDEEPTRIALPITSINBOULDERCLAYSOILSTODEPTHSOFUPTO12MISFEASIBLEUSINGBENCHINGTECHNIQUESANDSUMPPUMPINGOFGROUNDWATERINRECENTYEARS,IGSLHASUNDERTAKENSUCHDEEPTRIALPITSONSEVERALLARGEROADGROUNDINVESTIGATIONPROJECTSTHEDATAOBTAINEDFROMTHESEHASCERTAINLYENHANCEDTHEGEOTECHNICALDATAANDPROVIDEDABETTERUNDERSTANDINGOFTHEBULKPROPERTIESOFTHESOILSITISRECOMMENDEDTHATTHISWORKBECARRIEDOUTFOLLOWINGCOMPLETIONOFTHECABLEPERCUSSIONBOREHOLESANDROTARYCOREDRILLHOLESTHEGROUNDWATERREGIMEWITHINTHECUTAREAWILLPLAYANIMPORTANTROLEINGOVERNINGTHEFEASIBILITYOFEXCAVATINGDEEPTRIALPITSTHEINSTALLATIONOFSTANDPIPESANDPIEZOMETERSWILLGREATLYASSISTTHEUNDERSTANDINGOFTHEGROUNDWATERCONDITIONS,HENCETHEPURPOSEOFUNDERTAKINGTHISWORKLATEONINTHEGROUNDINVESTIGATIONPROGRAMMELARGEREPRESENTATIVESAMPLESCANBEOBTAINEDUSINGTRENCHBOXANDINSITUSHEARSTRENGTHMEASUREDONBLOCKSAMPLESTHESTABILITYOFTHEPITSIDEWALLSANDGROUNDWATERCONDITIONSCANALSOBEESTABLISHEDANDCOMPAREDWITHLEVELSINNEARBYBOREHOLESTANDPIPESORPIEZOMETERSOVERAPROMINENTCUTAREAOFSAY500M,THREEDEEPTRIALPITSCANPROVEINVALUABLEANDTHESPOILMATERIALALSOUSEDTOCARRYOUTSMALLSCALECOMPACTIONTRIALSFROMAVALUEENGINEERINGPERSPECTIVE,THECOSTOFEXCAVATINGANDREINSTATINGTHESEEXCAVATIONSCANBEEASILYRECOVEREDAPROVISIONALSUMCANBEALLOCATEDINTHEGROUNDINVESTIGATIONANDUSEDFORTHISWORK63HIGHQUALITYLARGEDIAMETERROTARYCOREDRILLINGTHISSYSTEMENTAILSTHEUSEOFLARGEDIAMETERROTARYCOREDRILLINGTECHNIQUESUSINGAIRMISTORPOLYMERGELFLUSHTRIPLETUBECOREDRILLINGISCARRIEDOUTTHROUGHTHEOVERBURDENSOILSWITHTHERECOVEREDMATERIALHELDINAPLASTICCORELINERCORERECOVERYINLOWPLASTICITYBOULDERCLAYHASBEENSHOWNTOBEEXTREMELYGOODTYPICALLYINEXCESSOF90THEHIGHCORERECOVERYPERMITSDETAILEDENGINEERINGGEOLOGICALLOGGINGANDPROVISIONOFSAMPLESFORLABORATORYTESTINGINDRUMLINAREAS,SUCHASTHOSEAROUNDCAVANANDMONAGHAN,IGSLHASFOUNDTHEUSEOFLARGEDIAMETERPOLYMERGELROTARYCOREDRILLINGTOBEVERYSUCCESSFULINRECOVERINGVERYSTIFF/HARDBOULDERCLAYSOILSFORDEEPROADCUTAREASWHERECABLEPERCUSSIONBOREHOLESANDTRIALPITSHAVEFAILEDTOPENETRATEINSITUTESTINGVANES,SPTSETCCANALSOBECARRIEDOUTWITHINTHEDRILLHOLETOESTABLISHSTRENGTHANDBEARINGCAPACITYOFDISCRETEHORIZONSLARGEDIAMETERROTARYDRILLINGCOSTSUSINGTHEAFOREMENTIONEDSYSTEMSARETYPICALLY50TO60GREATERTHANCONVENTIONALHQCORESIZE,BUTAGAINFROMAVALUEENGINEERINGASPECTCANPROVEMUCHMOREWORTHWHILEDUETOTHEQUALITYOFGEOTECHNICALINFORMATIONOBTAINED7SUPERVISIONOFGROUNDINVESTIGATIONPROJECTSCLOSEINTERACTIONANDMUTUALRESPECTBETWEENTHEGROUNDINVESTIGATIONCONTRACTORANDTHECONSULTINGENGINEERISCONSIDEREDVITALTOTHESUCCESSOFLARGEROADINVESTIGATIONPROJECTSASENIORGEOTECHNICALENGINEERFROMEACHOFTHEAFOREMENTIONEDPARTIESSHOULDLIASECLOSELYSOTHATTHEDIRECTIONANDSCOPEOFTHEINVESTIGATIONCANBECHANGEDTOREFLECTTHESTRATIGRAPHYANDGROUNDCONDITIONSENCOUNTEREDTHENATUREOFLARGEGROUNDINVESTIGATIONPROJECTSMEANSTHATTHEREMUSTBEGOODCOMMUNICATIONANDFLEXIBILITYINAPPROACHTOOBTAININGDATABEPREPAREDTOCOMPROMISEASMETHODSANDPROCEDURESSPECIFIEDMAYNOTBEAPPROPRIATEANDSITECONDITIONSCANQUICKLYCHANGEFROMASUPERVISIONASPECTBOTHCONTRACTORANDCONSULTINGENGINEER,THEEMPHASISSHOULDBEONTHEQUALITYOFSITEBASEDGEOTECHNICALENGINEERS,ENGINEERINGGEOLOGISTSASOPPOSEDTOQUANTITYWHEREWORKISDUPLICATED9CONCLUSIONSCLOSECOOPERATIONISNEEDEDBETWEENGROUNDINVESTIGATIONCONTRACTORSANDCONSULTINGENGINEERSTOENSURETHATTHEGEOTECHNICALINVESTIGATIONWORKFORTHEROADSNDPCANBESATISFACTORILYCARRIEDOUTMANYSOILSARETOOEASILYREJECTEDATSELECTION/DESIGNSTAGEITISHOPEDTHATTHEPROPOSEDMETHODSOUTLINEDINTHISPAPERWILLASSISTDESIGNENGINEERSDURINGSCOPINGANDSPECIFYINGOFGROUNDINVESTIGATIONWORKSFORROADPROJECTSWITHMODERNINSTRUMENTATION,MONITORINGOFEARTHWORKSDURINGCONSTRUCTIONISVERYSTRAIGHTFORWARDPOREWATERPRESSURES,LATERALANDVERTICALMOVEMENTSCANBEEASILYMEASUREDANDPROVIDEIMPORTANTFEEDBACKONTHEPERFORMANCEOFTHEENGINEEREDSOILSPHASINGOFTHEGROUNDINVESTIGATIONWORKS,PARTICULARLYLABORATORYTESTINGISCONSIDEREDVITALSOTHATTHEDATACANBEPROPERLYEVALUATEDDISPOSALOFMARGINALSOILSWILLBECOMEINCREASINGLYDIFFICULTANDMOREEXPENSIVEASTHEWASTELICENSINGREGULATIONSARETIGHTENEDTHEADVENTOFLANDFILLTAXINTHEUKHASSEENTHOROUGHEXAMINATIONOFALLSOILSFORUSEINEARTHWORKSTHISISLIKELYTOPROVIDEASIMILARINCENTIVEANDCHALLENGETOGEOTECHNICALANDCIVILENGINEERSINIRELANDINTHECOMINGYEARSACERTIFICATIONAPPROACHCOMPARABLEWITHTHATOUTLINEDSHOULDBECONSIDEREDBYTHENRAFORGROUNDINVESTIGATIONANDEARTHWORKACTIVITIES土方工程的地基勘察與施工摘要當(dāng)工程場地的處理面積有限且填方工程費(fèi)用大量增加時(shí)，土方工程的地基勘察設(shè)計(jì)與施工已逐漸地變得重要。由于冰漬土以及含礫粘土的提出使土方工程地基勘察方法的綱要比傳統(tǒng)的勘察方法更詳細(xì)。本文提出“巖土認(rèn)證”觀點(diǎn)以及對(duì)地基勘察與土方工程相結(jié)合的優(yōu)點(diǎn)加以概要說明。1、引言許多愛爾蘭含礫粘土的勘察與再利用評(píng)價(jià)使巖土工程師與道路工程師感到為難。這些冰漬土或含礫粘土主要表現(xiàn)為低可塑性而且還含有從粘土到漂石的不同粒徑顆粒。大部分本地粘土與淤泥質(zhì)土中包含不同比例的砂、礫石、卵石、漂石。顆粒級(jí)配控制著土體的行為，而且淤泥使土體性質(zhì)易受天氣變化影響。土體含水量隨著地區(qū)不同而不同，從都柏林硬灰黑含礫粘土的7到中部、西南部或西北部淺灰色含礫粘土沉積物的2025。含礫粘土吸附水的能力建立的較好但土方工程中計(jì)劃的不恰當(dāng)常導(dǎo)致其擴(kuò)大。一般來說，良好級(jí)配的土體對(duì)于含水量的輕微變大相當(dāng)敏感，將導(dǎo)致強(qiáng)度下降或不適合用作工程回填土。許多含礫粘土（尤其中等淤泥質(zhì)土或良好級(jí)配的砂）在選擇階段已經(jīng)被篩除，但事實(shí)上它們能對(duì)壓縮或強(qiáng)度起到特定的作用。篩選過程應(yīng)盡量使用本地土體或者回填區(qū)或路堤邊性質(zhì)相對(duì)較差的土體，通過仔細(xì)評(píng)價(jià)應(yīng)加以應(yīng)用。回填材料必須保持一定的含水量，既不能太濕導(dǎo)致土體不穩(wěn)定也不能太干以致不能被充分壓縮。高含水量、低強(qiáng)度含礫粘土適用于低路堤回填（相當(dāng)于2到25米的高度）但不適用于沒有使用土工織布隔離與回填層的土方回填工程。因此，土方工程承包商充分認(rèn)識(shí)土體的處理特性相當(dāng)重要，因?yàn)樵S多工程都受到挖掘設(shè)備通行能力的影響。2、傳統(tǒng)地基勘察方法對(duì)于道路工程來講，地基勘察最基本目標(biāo)是對(duì)土體適用性進(jìn)行類似表61的分類，該表源于國家檔案登記處2000年3月版的道路施工規(guī)范。目前大部分道路施工中的地基勘察包含以下提供有關(guān)巖土參數(shù)的試驗(yàn)方法取樣孔靜壓法取樣動(dòng)力探測回轉(zhuǎn)鉆進(jìn)原位測試（標(biāo)準(zhǔn)貫入試驗(yàn)，變水頭滲透試驗(yàn)，巖土物理試驗(yàn)等）室內(nèi)試驗(yàn)評(píng)價(jià)場地工作的重要性特別是評(píng)價(jià)土體深部取樣區(qū)域的適用性時(shí)不能過分強(qiáng)調(diào)其適用性。靜壓法取樣通常將取樣器下沉至要求深度進(jìn)行取樣，并每間隔一米進(jìn)行取樣。在許多情況下，靜壓法取樣由于卵石、漂石阻礙不能壓入非常堅(jiān)硬的含礫粘土。土樣在鉆孔內(nèi)應(yīng)盡量少擾動(dòng)，但級(jí)配變壞是很正常的，級(jí)配變壞將導(dǎo)致土樣分類不夠精確。取樣孔對(duì)于恢復(fù)適當(dāng)尺寸的土樣以及觀察碎屑巖在卵石、漂石中所占比例來說應(yīng)該是適當(dāng)?shù)?。因此，詳盡且精確的地區(qū)描述取樣區(qū)域以及取樣空來說都相當(dāng)重要，而且還為它們提供了檢查土體在鉆孔范圍以外性質(zhì)的良機(jī)。取樣孔也提供了孔壁穩(wěn)定性的評(píng)價(jià)以及觀察孔壁內(nèi)水進(jìn)入時(shí)所造成的影響。一位有經(jīng)驗(yàn)的巖土工程師或工程地質(zhì)專家應(yīng)監(jiān)督取樣孔工作以及土樣的恢復(fù)。因?yàn)橥翗有再|(zhì)為土樣敏感性提供了信息，所以取樣時(shí)土體性質(zhì)應(yīng)被密切關(guān)注，尤其是水從小顆粒區(qū)域遷移到良好級(jí)配區(qū)域。而且土體在開挖時(shí)的條件為其原位條件提供了一個(gè)相對(duì)精確的評(píng)價(jià)。3、土的分類土的描述與分類應(yīng)該依照英國標(biāo)準(zhǔn)5930（1999）進(jìn)行并依照英國標(biāo)準(zhǔn)1337（1990）進(jìn)行測試。土的工程描述應(yīng)基于按粒徑大小分級(jí)并依照良好級(jí)配土的可塑性進(jìn)行補(bǔ)充。對(duì)于許多冰漬土或含礫粘土（混合土）的難點(diǎn)在于其描述與工程性質(zhì)測試的評(píng)價(jià)。關(guān)于以前的地基勘察綱要，愛爾蘭含礫粘土的粘土與淤泥質(zhì)土中常由易變比例的砂、礫石、卵石組成。良好級(jí)配且含水量為1015的低可塑性土最難進(jìn)行描述與分類。現(xiàn)在英國標(biāo)準(zhǔn)5930（1999）已認(rèn)識(shí)到描述“混合土”所存在的難點(diǎn)土的良好級(jí)配較之顆粒尺寸對(duì)于控制著土的工程性質(zhì)更優(yōu)越。一個(gè)關(guān)鍵參數(shù)在土分類以及理解過程中經(jīng)常被低估，該參數(shù)就是滲透系數(shù)K。檢查土的顆粒級(jí)配將間接說明土的滲透系數(shù)的大小。假如可能，為了準(zhǔn)確評(píng)價(jià)土體的排水特性，三軸單元試驗(yàn)將采用無擾動(dòng)原狀土樣或高質(zhì)量土樣進(jìn)行試驗(yàn)。低可塑性的中等滲透性含礫粘土K大約在105到107米秒范圍內(nèi)能經(jīng)常通過不同排水條件進(jìn)行“模擬”。其必須在取樣區(qū)域安裝排水邊界以及水坑邊界或借用鉆孔以減少土樣的含水量。因此，由于含水量的小量減少，工程性質(zhì)復(fù)雜的冰漬土也能當(dāng)作合適的工程填土加以應(yīng)用。4、土工試驗(yàn)由于室內(nèi)試驗(yàn)的許多規(guī)定使其被建議用作土的最后試驗(yàn)。土的工程參數(shù)列于表61，該表源于國家檔案登記處2000年3月版的道路施工規(guī)范。其中包含以下內(nèi)容含水量顆粒級(jí)配塑限加州承載比密實(shí)度（最優(yōu)含水量）重塑土不排水抗剪強(qiáng)度當(dāng)進(jìn)行室內(nèi)試驗(yàn)時(shí)，大量的關(guān)鍵因素應(yīng)該被考慮。密實(shí)度加州承載比MCV試驗(yàn)土樣小于20MM。含水量測試試樣應(yīng)小于20MM以提供真實(shí)有效的對(duì)比。壓縮時(shí)孔隙壓力未加以考慮可能導(dǎo)致室內(nèi)與實(shí)際存在相當(dāng)大的差異。土樣測試的準(zhǔn)備方法必須被明確規(guī)定，而且試驗(yàn)應(yīng)在指定試驗(yàn)室進(jìn)行。進(jìn)行含礫粘土的含水量測試時(shí)必須非常小心謹(jǐn)慎。理想地說，土的含水量應(yīng)與其粒徑有關(guān)，而且還有相應(yīng)的級(jí)配分析曲線，雖然該曲線不是具有實(shí)際應(yīng)用價(jià)值。在大部分情況下，含水量被應(yīng)用于密實(shí)度被認(rèn)為是提供了關(guān)于建立含礫粘土適用性特征的最好方法。由于含水量能在開挖后快速評(píng)價(jià)土體的適用性，故強(qiáng)烈建議在取樣孔中對(duì)其進(jìn)行測試。因此，含水量刻度能夠在實(shí)驗(yàn)室內(nèi)不同含水量增量情況下被采用。土樣擾動(dòng)常發(fā)生在搬運(yùn)過程中，這將對(duì)含水量的結(jié)果產(chǎn)生重大的影響。地質(zhì)科學(xué)研究所在進(jìn)行低可塑性含礫粘土含水量測定時(shí)已經(jīng)土樣含水量由于時(shí)間的推移（2到7天）存在巨大的差異。許多上述低可塑性含礫粘土表現(xiàn)出與時(shí)間相關(guān)的含水量變化特性。其變化值主要由于土樣取樣時(shí)的排水條件，土樣運(yùn)移以及其體積的膨脹與土中水的遷移將導(dǎo)致土樣破壞或者強(qiáng)度下降。以上資料對(duì)于設(shè)計(jì)者以及土方工程承包商來說都很重要，因?yàn)檫M(jìn)行上述規(guī)定的測試時(shí)它提供了設(shè)計(jì)者以及土方工程承包商理解土體特性的機(jī)會(huì)。它能說明在某些情況下先進(jìn)行排水的所存在的優(yōu)點(diǎn)。對(duì)于混合土來說，對(duì)土方工程進(jìn)行開挖時(shí)加快排水工程非常有必要。含礫粘土的加州承載比測試也需要非常小心謹(jǐn)慎，尤其是開展測試前所采用的準(zhǔn)備工作。設(shè)計(jì)工程師必須意識(shí)到這一點(diǎn)，因?yàn)闇?zhǔn)備工作的誤差將導(dǎo)致試驗(yàn)結(jié)果的明顯不同。經(jīng)驗(yàn)表明，采用25或4公斤的錘進(jìn)行含礫粘土的靜態(tài)擊實(shí)將導(dǎo)致超高的孔隙壓力，因此將導(dǎo)致加州承載比值變低。被擊實(shí)含礫粘土的硬化相當(dāng)重要，因?yàn)橥恋挠不瘜⑹箍紫端畨毫οⅰ?、土的工程分類依照英國標(biāo)準(zhǔn)道路施工規(guī)范，一般的粘性填土分類如表61如下所示2A濕粘性填土2B干粘性填土2C含石粘性填土2D粉質(zhì)粘性填土首先按可接受性進(jìn)行提供土樣特性，然后設(shè)計(jì)工程師在實(shí)驗(yàn)室分類以及工程性質(zhì)測試基礎(chǔ)進(jìn)行決定土工程分類的上下限。愛爾蘭含礫粘土基本上都屬于2C含石粘性填土。道路施工規(guī)范612條列出了擊實(shí)方法。兩種現(xiàn)有的規(guī)程原狀土樣擊實(shí)重塑土樣擊實(shí)重塑土樣擊實(shí)被認(rèn)為最實(shí)用，特別是在土方工程合同初期階段良好的擊實(shí)控制數(shù)據(jù)可被利用。檢驗(yàn)擊實(shí)質(zhì)量時(shí)，最小干密度對(duì)于合同承包商來說是最有用的。一旦土樣被認(rèn)可或滿足工程分類要求，然后原位密度才能進(jìn)行測定，當(dāng)土樣中含石量較低時(shí)，通常采用核子測定儀或換砂試驗(yàn)進(jìn)行測定。當(dāng)布置或擊實(shí)回填土?xí)r，原位干密度能夠得到檢驗(yàn)