作者:标准资料网 时间:2024-05-20 00:09:03   浏览:8059   来源:标准资料网

【英文标准名称】:StandardTestMethodforIdentificationandClassificationofDispersiveClaySoilsbythePinholeTest
【原文标准名称】:用针孔试验做分散粘土识别和分类的标准试验方法
【标准号】:ASTMD4647-2006e1
【标准状态】:现行
【国别】:美国
【发布日期】:2006
【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】:D18.06
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:clay;clay(dispersive);collodialerodibility;dispersibility;dispersivity;dispersion;dispersiveclays;erosion;pinhole;soils;Earthwork;Flowandflowrate--soil/rock/relatedmaterials;Nondispersiveclaysoil;Pinholetest;Propertydamage/
【摘要】:Thepinholetestprovidesonemethodofidentifyingthedispersivecharacteristicsofclaysoilsthataretobeorhavebeenusedinearthconstruction.Thepipingfailuresofanumberofhomogeneousearthdams,erosionalongchannelorcanalbanks,andrainfallerosionofearthenstructureshavebeenattributedtothecolloidalerosionalongcracksorotherflowchannelsformedinmassesofdispersiveclay(2).Thistestmethodmodelstheactionofwaterflowingalongacrackinanearthembankment.Otherindirecttests,suchasthedoublehydrometertest(TestMethodD4221),thecrumbtest(3,4),thatrelatestheturbidityofacloudofsuspendedclaycolloidsasanindicatoroftheclaydispersivity,andchemicalteststhatrelatethepercentageofsodiumtototalsolublesaltcontentofthesoilarealsousedasindicatortestsofclaydispersibility(2).Thecomparisonofresultsfromthepinholetestandotherindirecttestsonhundredsofsamplesindicatesthattheresultsofthepinholetesthavethebestcorrelationwiththeerosionalperformanceofclaysoilsinnature.MethodAandMethodCofthepinholetestrequiretheevaluationofcloudinessofeffluent,finalsizeofthepinhole,andcomputationofflowratesthroughthepinholeinordertoclassifythedispersivecharacteristicsofthesoil.MethodBrequiresonlytheevaluationofthecloudinessofeffluentandfinalsizeofthepinholetoclassifythedispersivecharacteristicsofthesoil.ThecomputationofflowratesthroughthepinholeinMethodAservesprimarilyasaguidetotheproperequipmentandspecimenperformanceundersequentialpressuresappliedduringthetest.Allmethodsproducesimilarresultsandanymethodcanbeusedtoidentifydispersiveclays.TheuseofMethodAorMethodCresultsintheaccumulationofdatarelativetosequentialflowratesthroughthepinholeandconsequentenlargementorerosionofthehole.Thepinholeerosiontestwasdevelopedforthepurposeofidentifyingdispersivesoilsandisnotintendedtobeageometricallyscaledmodelofaprototypestructure.Sincethetheoryofsimilitudewasnotusedinthedesignofthepinholetest,quantitativedataarenotobtained.Thequantityofflowthroughthepinhole,amountofsoilerosion,ortherateofsoilerosionshouldnotbeextrapolatedtoactualfieldconditions(3).However,suchdatamaybeusefulinperformingqualitativeevaluationsoftheconsequencesofsucherosionintermsofdamfailure,lossoflifeandproperty.Theyalsomaybeusedinconsideringthecosteffectivenessofdefensivedesignmeasuresnecessarytominimizetheeffectsoffailureduetodispersiveclays.Forexample,theamountofcolloidalerosionthatwilloccurinasoilclassedasND2(veryslightlydispersive)willbeverysmallforarelativelylongperiodoftime.Sucherosionmaynotbesignificantinevaluatingthecost-benefitrelationshipsinprojectswherepublicsafetyisnotinvolvedorwherenormalmaintenanceprocedureswillhandletheproblem.Insuchcases,classifyingthesoilasND(nondispersive)usingMethodBofthepinholetestshouldbeadequate.Pinholeteststhatresultinclassifyingsoilasslightlydispersive(ND3byMethodAorMethodCorSDbyMethodB)indicatehighuncertaintyabouttheexistenceofsignificantproblemstobeconsideredinthedesignorstabilityofastructure.Insuchcases,itisadvisabletoresampleandtestanumberofothersoilsfromthesameareatogenerateanadequatestatisticalsampleforproblemevaluation.Theoriginalslightlydispersivesamplemaycomefromanareaontheedgeofamorehighlydispersivesoil.Inafewphysiographicareasorgeoclimaticconditions,orboth,neitherthepinhole......
【中国标准分类号】:P21
【国际标准分类号】:93_020
【页数】:11P.;A4
【正文语种】:英语