Review of Soil-Water Characteristic Curve Equations

《Review of Soil-Water Characteristic Curve Equations》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、REVIEWOFSOIL..WATERCHARACTERISTICCURVEEQUATIONSByE.C.Leong1andH.Rahanljo%ABSTRACT:Practicalapplicationsofunsaturatedsoilmechanicsstilllagbehindthestate-of-the-artknowledge.Themainstumblingblockisthetime-consumingprocessesinvolvedinthemeasurementoftheunsatu

2、ratedsoilparametersrequiredforthe.constitutivemodels.Recentresearchbasshownthatthesoil-watercharacteristiccurvesofasoilcanbeusedintheestablishmentofanumberofdieunsaturatedsoilparameters.Inmanyapplicationsithasbecomeobviousthatasatisfactoryequationfordescri

3、bingthesoil-watercharacteristiccurvewillsimplifythedetenninationofthesoilparameters.Overtheyearsanumberofequationshavebeensuggested.Mostoftheseequationshavelimitedsuccessdependingonsoiltypes..1bispaperevaluatesthemorepopularequationsthathavebeensuggestedan

4、dshowsthatalltheequationscanbederivedfromasinglegenericform.Oneequationhasbeenidentifiedthatperformsverywellforallsoiltypes.Ifthisequationisincommonusage,usefuldatabasesonunsaturatedsoilparameterscanbemoreeasilyestablishedforpracticalapplicationsofunsatura

5、tedsoilmechanics...INTRODUCTIONwatercharacteristiccurveafewparameterscanbedefined:thesaturatedvolumetricwatercontent,elftheresidualvolumetricFredlundandMorgenstern(1977)concludedthatnetnormalstressandmatricsuctionarethestressstatevariablesofanwatercontent,

6、entheair-entryvalueorbubblingpressure."'b.unsaturatedsoil.Thewatercontentinanunsaturatedsoilisaandtheresidualaircontent,e.(Fig.2).Anumberofequationshavebeensuggestedforthesoil-watercharacteristiccurveandfunctionofthesuctionpresentinthesoil.Thisrelationship

7、betweenthewatercontentinasoilandthesuctioncanbealmostalltheequationssuggestedcanbederivedfromtheexpressedinaplotofvolumetricwatercontentversussuctionfonowinggenericform:thatisknownasthesoil-watercharacteristiccurve.Thiscurveal~+lZIexp(a36b,)=a.tIf'+a,eXp(a

8、61J1'2)+a,(1)ismorecommonlyreferredtoasasoil-waterretentioncurveinsoilsciences.Thesoil-watercharacteristiccurveofasoilwherea"lZI.a3.a..a,.ll6.0.,.bItandb2areconstants;'"=canbeobtainedusingapressureplatedevice