【英文标准名称】:StandardTestMethodforDeterminingtheEffectofFreeze-ThawonHydraulicConductivityofCompactedorIntactSoilSpecimensUsingaFlexibleWallPermeameter
【原文标准名称】:使用一柔壁渗透计对压实的或原状土壤样品液体导电性冻融效果测定的标准试验方法
【标准号】:ASTMD6035-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D18.19
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:coefficientofpermeability;cover;freeze-thaw;hydraulicconductivity;liner;permeameter,Coefficientofpermeability;Compactioncontrol;Cover;Freezingandthawing--soil/rock;Hydraulicconductivity/transmissivity;Liner;Permeability--soil/roc
【摘要】:Thistestmethodidentifiesthechangesinhydraulicconductivityasaresultoffreeze-thawonnaturalsoilsonly.Itistheuser''sresponsibilitywhenusingthistestmethodtodeterminetheappropriatemoisturecontentofthelaboratory-compactedspecimens(thatis,dry,wet,oratoptimummoisturecontent)(Note2).Note28212;Itiscommonpracticetoconstructclaylinersandcoversatoptimumorgreaterthanoptimummoisturecontent.Specimenscompacteddryofoptimummoisturecontenttypicallydonotcontainlargerporesizesasaresultoffreeze-thawbecausetheeffectsoffreeze-thawareminimizedbythelackofwaterinthesample.Therefore,theeffectoffreeze-thawonthehydraulicconductivityisminimal,orthehydraulicconductivitymayincreaseslightly.,Therequestormustprovideinformationregardingtheeffectivestressestobeappliedduringtesting,especiallyfordeterminingthefinalhydraulicconductivity.Usinghigheffectivestresses(thatis,35kPa(5psi)asallowedbyTestMethodD5084)candecreaseanalreadyincreasedhydraulicconductivityresultinginlowerfinalhydraulicconductivityvalues.Thelong-termeffectoffreeze-thawonthehydraulicconductivityofcompactedsoilsisunknown.Theincreasedhydraulicconductivitycausedbyfreeze-thawmaybetemporary.Forexample,theoverburdenpressureimpartedbythewasteplacedonasoillinerinalandfillafterbeingsubjectedtofreeze-thawmayreducethesizeofthecracksandporesthatcausetheincreaseinhydraulicconductivity.Itisnotknownifthepressurewouldovercomethemacroscopicallyincreasedhydraulicconductivitysufficientlytoreturnthesoiltoitsoriginalhydraulicconductivity(priortofreeze-thaw).Forcasessuchaslandfillcovers,wheretheoverburdenpressureislow,theincreaseinhydraulicconductivityduetofreeze-thawwilllikelybepermanent.Thus,therequestormusttaketheapplicationofthetestmethodintoaccountwhenestablishingtheeffectivestress.Thespecimenshallbefrozentox2212;15x00B0;Cunlesstherequestorspecificallydictatesotherwise.Ithasbeendocumentedintheliteraturethattheinitial(thatis,0tox2212;15x00B0;C)freezingconditioncausesthemostsignificanteffectsinhydraulicconductivity.Freezingrateandultimatetemperatureshouldmimicthefieldconditions.Ithasbeenshownthatsuperfreezing(thatis,freezingthespecimenatverycoldtemperaturesandveryshorttimeperiods)produceserroneousresults.Thethawedspecimentemperatureandthawrateshallmimicfieldconditions.Thawingspecimensinanoven(thatis,overheating)willproduceerroneousresults.Literaturerelatingtothissubjectindicatesthattheeffectsoffreeze-thawusuallyoccurbyCycle10,thusitisrecommendedthatatleast10freeze-thawcyclesshallbeperformedtoensurethatthefulleffectsoffreeze-thawaremeasured.Ifthehydraulicconductivityvaluesarestillincreasingafter10freeze-thawcycles,thetestmethodshallbecontinued(thatis,morefreeze-thawcyclesshallbeperformed).Note38212;Thequalityoftheresultproducedbythisstandardisdependentonthecompetenceofthepersonnelperformingit,andthesuitabilityoftheequipmentandfacilitiesused.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting/sampling/inspection/etc.UsersofthisstandardarecautionedthatcompliancewithPracticeD3740doesnotinitselfassurereliableresults.Reliableresultsdependonmanyfact............
【中国标准分类号】:D10
【国际标准分类号】:13_080_20
【页数】:5P.;A4
【正文语种】:英语