Vane Shear Test

To find shear strength of a given soil specimen. ... The structural strength of soil is basically a problem of shear strength. Vane shear test is a useful method ... VaneShearTest OBJECTIVE Tofindshearstrengthofagivensoilspecimen. NEEDANDSCOPE Thestructuralstrengthofsoilisbasicallyaproblemofshearstrength. Vanesheartestisauseful methodofmeasuringtheshearstrengthofclay.Itisacheaperandquicker method.Thetestcanalsobeconductedinthelaboratory.Thelaboratoryvane sheartestforthemeasurementofshearstrengthofcohesivesoils,isuseful forsoilsoflowshearstrength(lessthan0.3kg/cm2)forwhich triaxialorunconfinedtestscannotbeperformed.Thetestgivestheundrained strengthofthesoil.Theundisturbedandremouldedstrengthobtainedareuseful forevaluatingthesensitivityofsoil. PLANNINGANDORGANIZATION EQUIPMENT 1.Vaneshearapparatus. 2.Specimen. 3.Specimencontainer. 4.Callipers. EXPERIMENTALPROCEDURE 1.Preparetwoorthreespecimens ofthesoilsampleofdimensionsofatleast37.5mmdiameterand75mmlength inspecimen.(L/Dratio2or3). 2.Mountthespecimencontainer withthespecimenonthebaseofthevaneshearapparatus.Ifthespecimen containerisclosedatoneend,itshouldbeprovidedwithaholeofabout1mm diameteratthebottom. 3.Gentlylowertheshearvanes intothespecimentotheirfulllengthwithoutdisturbingthesoilspecimen.The topofthevanesshouldbeatleast10mmbelowthetopofthespecimen.Notethe readingsoftheangleoftwist. 4.Rotatethevanesatanuniform ratesay0.1o/sbysuitableoperatingthetorqueapplicationhandle untilthespecimenfails. 5.Notethefinalreadingofthe angleoftwist. 6.Findthevalueofbladeheight incm. 7.Findthevalueofbladewidth incm.  Calculations:    Observations: Nameofthe project: Soil description:  S.No Initial Reading (Deg)   Final Reading (Deg.)   Difference (Deg.)   T=Spring Constant/180xDifference Kg-cm   S=TxG Kg/cm2     Average 'S' Kg/cm2   SpringConstant Kg-cm                                                                                                               General remarks: Thistestis usefulwhenthesoilissoftanditswatercontentisnearertoliquidlimit.