Microstructural changes in soils [Elektronische Ressource] : rheological investigations in soil mechanics / vorgelegt von Wibke Markgraf

De
InstitutfürPflanzenernährungundBodenkundederChristianAlbrechtsUniversitätzuKielMicrostructuralChangesinSoilsRheologicalInvestigationsInSoilMechanicsKumulativeDissertationzurErlangungdesDoktorgradesderAgrarundErnährungswissenschaftlichenFakultätderChristianAlbrechtsUniversitätzuKielvorgelegtvonDipl. Geogr. Wibke Markgraf geboreninLangenhagen/HannoverKiel,2006Dekan:Prof.Dr.J.Krieter1.Berichterstatter:Prof.Dr.R.Horn2.Berichterstatter:Prof.Dr.W.RabbelTagdermündlichenPrüfung:02.11.2006ContentsGedruckt mit Genehmigung der Agrar und ErnährungswissenschaftlichenFakultätderChristianAlbrechtsUniversitätzuKielVertrieb:InstitutfürPflanzenernährungundBodenkundeChristianAlbrechtsUniversitätzuKielOlshausenstr.40D24107Kiel(email:smevlan@soils.unikiel.de)ISSN0933680XPreis:10,Euro(incl.Versandkosten)2"What we know is a drop. What we don't know is an ocean." IsaacNewton(16431727)ContentsPARTI ..................................................................................... 11 1.IntroductionandFundamentals ............................................................ 13 1.1Introduction.................................................................................. 13 1.2Fundamentalsofsoilmicromechanics....
Publié le : dimanche 1 janvier 2006
Lecture(s) : 35
Source : D-NB.INFO/1007366494/34
Nombre de pages : 167
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InstitutfürPflanzenernährungundBodenkunde
derChristianAlbrechtsUniversitätzuKiel


MicrostructuralChangesinSoils

RheologicalInvestigations

InSoilMechanics




KumulativeDissertationzurErlangungdesDoktorgrades
derAgrarundErnährungswissenschaftlichenFakultät
derChristianAlbrechtsUniversitätzuKiel

vorgelegtvon

Dipl. Geogr. Wibke Markgraf

geboreninLangenhagen/Hannover



Kiel,2006






Dekan:Prof.Dr.J.Krieter
1.Berichterstatter:Prof.Dr.R.Horn
2.Berichterstatter:Prof.Dr.W.Rabbel
TagdermündlichenPrüfung:02.11.2006

Contents





























Gedruckt mit Genehmigung der Agrar und Ernährungswissenschaftlichen
FakultätderChristianAlbrechtsUniversitätzuKiel

Vertrieb:
InstitutfürPflanzenernährungundBodenkunde
ChristianAlbrechtsUniversitätzuKiel
Olshausenstr.40
D24107Kiel
(email:smevlan@soils.unikiel.de)

ISSN0933680X
Preis:10,Euro(incl.Versandkosten)

2


"What we know is a drop.
What we don't know is an ocean."

IsaacNewton(16431727)



Contents
PARTI ..................................................................................... 11
1.IntroductionandFundamentals ............................................................ 13
1.1Introduction.................................................................................. 13
1.2Fundamentalsofsoilmicromechanics................................................ 16
1.2.1Particleassociations.................................................................. 16
1.2.2Particleforces .......................................................................... 19
1.2.3Interparticleforces ................................................................... 20
1.2.4Effectiveandintergranularstress................................................ 21
1.3Deformationcharacteristics ............................................................. 24
1.4SoilmechanicsatthemicroscaleandRheometry ................................ 26
1.5Objectives .................................................................................... 28
PARTII .................................................................................. 31
2.AnApproachtoRheometryinSoilMechanics:StructuralChangesinBentonite,
ClayeyandSiltySoils ............................................................................. 33
Abstract............................................................................................. 33
2.1Introduction.................................................................................. 34
2.1.1Researchobjectives .................................................................. 34
2.2Theoreticalremarksonrheometry .................................................... 38
2.2.1Definitionofterms.................................................................... 38
2.2.1.1Newton’slawofidealfluids ................................................ 39
2.2.1.2Hooke’slaw:ElasticflowbehaviourandshearmodulusG .......... 40
2.2.1.3Binghammodel:viscoplasticbehaviour................................... 41
2.2.2Viscoelasticity .......................................................................... 42

3Contents



2.2.2.1Oscillatoryshear:Maxwell’sandKelvin/Voigtmodel ................. 43
2.2.2.2Amplitudesweeptest........................................................... 44
2.2.3Measuringdevice...................................................................... 45
2.3Material........................................................................................ 46
2.3.1Substrates............................................................................... 46
2.3.1.1IbecoSeal80..................................................................... 46
2.3.1.2AvdatLoess ....................................................................... 47
2.3.1.3VertisolandClayeyOxisol .................................................... 47
2.3.2Preparationofsamples.............................................................. 48
2.3.2.1PreparationofIbecoSeal80................................................. 48
2.3.2.2PreparationofAvdatLoess,VertisolandOxisol ........................ 49
2.4Results......................................................................................... 49
2.4.1Salteffects.............................................................................. 49
2.4.2Shearbehaviour....................................................................... 51
2.4.3Claymineralogicaleffects .......................................................... 51
2.5Discussion .................................................................................... 52
2.6Conclusions................................................................................... 54
2.7Acknowledgment ........................................................................... 55
2.8References.................................................................................... 55
+3.RheologicalStrengthAnalysisofK treatedandofCaCO richsoils............ 59 3
Abstract............................................................................................. 59
3.1Researchobjectives........................................................................ 60
3.2Someremarksabouttherheologicalmethod...................................... 63
3.2.1Hooke’slaw:ElasticflowbehaviourandshearmodulusG ............... 63
3.2.2Newton’slawofidealfluids ........................................................ 64
3.2.3Viscoelasticity .......................................................................... 65
3.2.4Amplitudesweeptest................................................................ 65
3.2.4.1TestConfiguration............................................................... 67
3.3Material........................................................................................ 67
3.3.1Substrates............................................................................... 68
3.3.2Preparationofsamples.............................................................. 69
3.4Results......................................................................................... 70
+3.4.1Effectsofwatercontent,K andNaCl .......................................... 70
3.4.2Texturaleffects ........................................................................ 73
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3.5Discussion .................................................................................... 74
3.6Conclusions................................................................................... 75
3.7Acknowledgments.......................................................................... 76
3.8References.................................................................................... 76
4.RheometryinSoilMechanics:MicrostructuralChangesinaCalcaricGleysol
andaDystricPlanosol............................................................................. 79
Abstract............................................................................................. 79
4.1Researchobjectives........................................................................ 80
4.2Rheometryinsoilmechanics:someremarks ...................................... 81
4.3MaterialandMethods ..................................................................... 82
4.3.1Preparationofsamples.............................................................. 83
4.3.2Amplitudesweeptest............................................................... 83
4.3.3Testconfiguration..................................................................... 85
4.4Results......................................................................................... 85
4.5Discussion .................................................................................... 88
4.6Conclusions................................................................................... 89
4.7Acknowledgments.......................................................................... 89
4.8References.................................................................................... 90
5.InteractionBetweenSEM/EDSAnalysesandRheologicalInvestigationsof
SouthBrazilianSoils............................................................................... 93
Abstract............................................................................................. 93
5.1Introduction.................................................................................. 95
5.2MaterialandMethods ..................................................................... 98
5.2.1GeographyandGeology ............................................................ 98
5.2.2Substrates............................................................................... 98
5.2.2.1Analyses............................................................................ 99
5.2.2.2Amplitudesweeptests(AST) .............................................. 100
5.2.2.3Scanningelectronmicroscopy(SEM) .................................... 101
5.2.2.4Watercontent .................................................................. 102
5.2.2.5Statistics ......................................................................... 102
5.3Results....................................................................................... 102
5.3.1Amplitudesweeptests(AST).................................................... 102
5.3.2DetectionofthemineralcompositionbySEMandEDSanalyses,and
XRD ............................................................................................. 106
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5.4Discussion .................................................................................. 109
5.5Conclusions................................................................................. 110
5.6Acknowledgments........................................................................ 111
5.7References.................................................................................. 111
PARTIII.............................................................................. 115
6.DiscussionandConclusions................................................................ 117
6.1General...................................................................................... 117
6.2Texturaleffects ........................................................................... 118
6.3Watercontent ............................................................................. 118
6.4Physicochemicalandcultivationeffects............................................ 119
6.5Rheologyandscanningelectronmicroscopy ..................................... 120
6.6Soiltoolinterfaceandupscalingconsiderations ............................... 121
7.Outlook .......................................................................................... 123
8.SummaryZusammenfassung ........................................................... 125
Summary......................................................................................... 125
Zusammenfassung ............................................................................ 127
9.Danksagung .................................................................................... 129
10.References .................................................................................... 131
PARTIV............................................................................... 143
AppendixA ......................................................................................... 145
AppendixB ......................................................................................... 151
AppendixC ......................................................................................... 154
AppendixD ......................................................................................... 155





6Contents



Figures

Fig. 1-1a)modularcompactrheometerMCR300;1pneumaticballbearing,andinstrumentlift;2
manualcontrol;3rotatingbob(25mm);4measuringplatewithPeltierunit;b)5controldisplay;
c) 6 profiled parallel plate measuring system (25PP MS) in detail (setting of zero,gap); d) 7
shearedsurfaceofasampleafteranappliedamplitudesweeptest(AST)underoscillating(OSC)
conditionswithcontrolledsheardeformation(CSD);durationofonetest:15,18minutes(f=0.5
Hz). .............................................................................................................................16
Fig. 1-2Aggregationofclayplatelets:edge,to,face(EF), face,to,face(FF)andedge,to,edge(EE)
independencyonthepH,value(accordingtoJasmundandLagaly,1993)................................17
Fig. 1-3Sand/siltgrainsandclayplateletsareformedtoanaggregate;thethreephasesofasoil,
gaseous, liquid, and solid , are combined by forces as generated due to several bonding
+ 2+ 2+mechanisms:ionic(Na ),covalent(Ca ,Mg ),hydrationmechanisms,capillaryforces(matric
potential, influencedby osmoticpotential),and associated menisci forces. Other bondsmaybe
builtuponorganicmatter(OM)compoundsandareinfluencedbymineralogicalfactorsaswellas
parameters,whichdefineporewatercharacteristics(e.g.saltconcentration). ..........................18
Fig. 1-4 Interparticle forces at the particle level: (a) skeletal forces by external loading, (b)
particlelevelforces,and(c)contactlevelforces(afterSantamarina,2003) .............................20
Fig. 1-5Contributionofskeletalforce(σ–u )andelectrochemicalforces(A,R)tointergranularo
forceσ:(a)parallelmodeland(b)seriesmodel(adaptedfromMitchellandSoga,2005). ..........22 i
Fig. 1-6 Four zones of deformation characterisation: stiffness degradation and plastic strain
development;anincreasingstiffnessdegradationisassociatedbyanincreaseofplasticstrain.The
ppart of plastic strain (dε ) is 0 in state A, the region of true and non,linear elasticity, is
tapproximatinginstateB,theregionofpreyielding,andequalstotalstrain(dε )instateC,thefull
plasticregion(afterJardine,1992)....................................................................................26
Fig. 1-7Rotund,platyandnaturalsoilmatrixincontactwithanoscillatingtool,here,aparallel,
platerheometerMCR300withaprofiledparallelplatemeasuringsystem,25mmindiameter(MS
25PP).Leftside:beforeoscillatoryshear,rightside:during/aftershearing(amplitudesweeptest).
Structural changes are induced by mechanical and chemical mechanisms or forces. Oscillatory
shearleadstoareorientation,compression,andfriction,ofsoilparticles.................................28
Fig. 2-1Soilcompounds,aggregation:negativelychargedsoilparticles,rotundsandorsiltgrains,
clay platelets, organic matter, pore water, including nutrients/cations between the particles
(differentmenisciforces)andairfilledpores.......................................................................34
Fig. 2-2Mechanicalbehaviourofclayplateletsandalignedsoilparticles:slidingshearbehaviour.
1 Platelets/aligned particles in gel state (aggregated), under steady stress condition;2 either
under steady or shear stress a sliding shear behaviour is given when external applied stress’
prevailinternal(structural)forces,theyieldstressisexceeded–compactionistheresult,bulk
densityincreases,(micro)poresystemcollapses..................................................................36
Fig. 2-3Mechanicalbehaviourofsandandsilt.1a,b:verticalstress(compression)appliedtotwo
singleparticles.In1awatermenisciwithaconcaveshapeinarestingstate,in1bwithaconvex
formduetotheappliedverticalstress.2:shearstressappliedtotwoparticles;watermenisci
showconcaveandconvexshapecongruentlytothedirectionofshear.Aturbulentshearbehaviour
istheresultofappliedstresstorotundparticles,eitherverticalorinshear. .............................37
Fig. 2-4SpringmodelaccordingtoHooke’slaw(idealelastic)anddashpotmodelaccordingto
Newton’sLaw(idealfluid)................................................................................................40
Fig. 2-5a)Idealisedflowcurves.Diagramadepictsgraphsthatrepresentidealplasticandideal
elastic materials.According toHooke’s law the value of the shear modulus G – comparable to
Young’smodulusE–dependsontheratioofshearstressτtotheshearstrain(deformation)γ.In
caseof idealelasticbodies,the graphstarts in the point of origin, increasingconstantly. Ideal
plasticmaterialshaveacertainyieldstressτ ;byreachingthispointthegraphrunsparalleltothey
y,axis,τ =const. ..........................................................................................................42 y
Fig. 2-5b)Graphsofanidealfluidandaviscoplasticbodyareillustrated.Agraphofanidealfluid
runsthroughthepointoforigin,theviscosityequalsthegradientresultingfromtheratioofthe
shearstresstotheshearrate.Thegraphofaviscoplasticbody,accordingtoBingham,reachesa
yieldpoint,τ =const.(τ )whiletheshearratedγ/dtincreases...............................................42 y B
Fig. 2-6ThecomplexshearmodulusG*asaresultfromthequotientoftheshearstresstothe
deformationinoscillatoryshear(indices standforamplitude),amodificationofHooke’slaw.TheA
lossmodulustan δasparameterofelastic,viscoelasticorplasticbehaviour:G”dividedbyG’.
tanδ>1viscouscharacter;tanδ=1viscoelastic;tanδ<1elasticbehaviour. ...........................42
Fig. 2-7 Principleof an oscillatoryshear. Natural substancese.g. soil or clay mineralsshow a
viscoelasticbehaviour(dashedline),reactingwithatemporaldelay,representedbythephaseshift
7Contents


angle δ.Drawn through line: elastic substances, dotted line: viscous materials. τ shear stressA
(constantamplitudeA)inoscillation,derivingfromHooke’slaw. ............................................44
Fig. 2-8 Amplitude sweep test: a constant frequency and a variable deformation are preset.
Result:storagemodulusG’(elasticbehaviour)andlossmodulusG”(viscousbehaviour)aswellas
thelimitoftheLVErangeγ .InthiscaseG’prevailsG”,agelcharacterisgivenintherestingL
state. ...........................................................................................................................44
Fig. 2-9a)ResultinggraphsofG’(storagemodulus)fromaconductedamplitudesweeptestwith
Avdatloess,saturatedwithdistilledwater(blanksquare),NaClsolutionsof0.01M(filledsquare)
and0.17M(blankcircle),respectively.StoragemoduliG’arecompared.Substratessaturatedwith
distilledwaterandNaClsolutionsofconcentrationshavesimilarelasticcharacteristics;athigher
concentrationsdifferencesbecomeapparent. ......................................................................50
Fig. 2-9b)WhilstinFig.2,9a)storagemoduliarecompared, lossmoduliG”areopposedinthis
case.ThegraphsofG”showananaloguedevelopingtoG’.Samplessaturatedwithdistilledwater
(blanktriangle)andNaClof0.01M(filledtriangle)havealmostthesameviscousparts,whereasat
aconcentrationof0.17M(1%)(blankcircle)G”increases,likewisetoG’. ................................50
Fig. 2-10ResultfromaconductedamplitudesweeptestwithIbecoSeal,80,saturatedwithNaCl
salt solution 0.01M. Basically, clay minerals are appropriate to show a distinctive LVE range
includingthelimitofdeformationγ andawelldefinedcrossoverofG’andG”,thetransgressionofL
theyieldpoint................................................................................................................51
Fig. 2-11ResultinggraphsofG’andG”fromconductedamplitudesweeptests.TheclayeyOxisol
andVertisol,bothsaturatedwithdistilledwaterarecompared.Accordingtotheirnaturalconditions
(e.g.texture,mineralogy)differencesinelasticandplasticpartscanbederivedfromtheplots.G’
Vertisol>G’clayeyOxisolinphase1;althoughtheintersectionofG’andG”oftheVertisolin
phase2isreachedearlier,thelevelofG’andG”remainshighcomparedtothekaoliniticOxisol.
TheVertisolshowsamoredistinctivepartof“storedelasticity”thantheclayeyOxisol. ..............52
Fig. 3-1Mechanicalbehaviourofclayplateletsandalignedsoilparticles:slidingshearbehaviour.
1 Platelets/aligned particles in gel state (aggregated), under steady stress condition;2 either
under steady or shear stress a sliding shear behaviour is given, when external applied stress’
prevailinternal(structural)forces,theyieldstressisexceeded–compactionistheresult,bulk
densityincreases,(micro)poresystemcollapses..................................................................62
Fig. 3-2Mechanicalbehaviourofrotundparticles.1a,b:verticalstress(compression)appliedto
twosingleparticles.In1111awatermenisciwithaconcaveshapeinarestingstate,in1111bwitha
convex formdue to theapplied verticalstress.2222: shearstress appliedto twoparticles; water
meniscishowconcaveandconvexshapecongruentlytothedirectionofshear.Aturbulentshear
behaviouristheresultofappliedstresstorotundparticles,eitherverticalorinshear................62
Fig. 3-3Representativeillustrationofresultinggraphsderivingfromconductedamplitudesweep
testswithcontrolledsheardeformation(CSD)[%].CurvesofG’(storagemodulus)andG”(loss
modulus)[Pa]areshown,whicharecharacterisedbythreestages:aninitialorplateauphase(1)
includingthelinearviscoelasticrange(LVErange),thatisdefinedbyadeformationlimitγ ,astageL
oftransgression(2)andafinalphase(3)ofstructuralcollapse..............................................66
Fig. 3-4StoragemodulusG’ofHallesamplesH1(filledrectangle)saturatedwithdistilledwater,
filled triangle: H7, filled circle: H15; blank symbols represent values of the storage modulus,
congruentlytoG’ofthefilledsymbols,derivingfrommeasurementsconductedonsoilsamples
whicharedrainedat–60hPa.Additionallyillustrated:linearviscoelasticrange(LVErange),thatis
definedbyadeformationlimitγ .(H1,7,15=Halle,1,7,and15cmdepth) ...........................71 L
Fig. 3-5StoragemodulusG’ofKasselsamplesKA2(filledrectangle)saturatedwithdistilledwater,
filledtriangle:KA5,filledcircle:KA8,filledrhombus:KA15;blanksymbolsrepresentvaluesofthe
storagemodulus,congruentlytoG’ofthefilledsymbols,derivingfrommeasurementsconducted
onsoilsampleswhicharedrainedat,60hPa.Thelinearviscoelasticrange(LVErange)aswellas
thedeformationlimitγ aregiven.(KA2,5,8,15=Kassel,2,5,8,and15cmdepth)................71 L
Fig. 3-6ResultsofconductedamplitudesweeptestsonAvdatLoess,saturatedwiththreeNaCl
saltsolutions.Filledcircle:0.01M;filledtriangle:0.1M;blankrectangle:0.17M.Incomparisonto
the samples originating from Halle and Kassel, differences in the level of the graphs become
obvious,whichderivefromtheinfluenceofNaCl. ................................................................72
Fig. 3-7 Storage modulus G’ and loss modulus G” are depicted, as results of two executed
+amplitudesweeptests with the K treated samples fromHalleand Kassel (drained at ,60hPa).
Filledrectangle:G’HalleH1;blankrectangle:G”HalleH1;filledtriangle:G’KasselKA2;blank
triangle: G” Kassel KA2. Decisive factorsare the durationof the three stages, the level of the
graphs,and,asanadditionalcriteria,theintersectionofG’andG”.........................................73
Fig. 4-1 Representing result deriving from an amplitude sweep test with controlled shear
deformation(CSD).ThecurveprogressionsofG’(storagemodulus),lightgreenblankrectangles,
andG”(lossmodulus),darkgreenblankrectangles,canbedividedintothreestages.Inphase1,
the stored elasticity can be defined and quantified. The LVE deformation range, including the
8Contents


deformationlimitisattributedtothisstate.Phase2isastageoftransgression,endinginphase3,
thestateofanirreversiblestructuralcollapse......................................................................84
Fig. 4-2PlottedgraphsofconductedAST(CSD)onNaCltreatedCalcaricGleysol(Soil03).0.1M
(blankrectangles),storagemodulus(lightgreen□),lossmodulus(darkgreen□)and1.0M(filled
rhombus’),storagemodulus(lightgreen♦),lossmodulus(darkgreen♦),undersaturated(a)and
drained@,60hPaconditions(b).(furtherexplanatio nsaregiveninthetext)...........................87
Fig. 4-3PlottedgraphsofconductedAST(CSD)onCaCl treatedCalcaricGleysol(Soil03).0.1M2
(blankrectangles),storagemodulus(lightgreen□),lossmodulus(darkgreen□),and1.0M(filled
rhombus’),storagemodulus(lightgreen♦),lossmodulus(darkgreen♦),undersaturated(a)and
drained@,60hPaconditions(b).(furtherexplanatio nsaregiveninthetext)...........................87
Fig. 4-4SEMmicrographsofSoil04(DystricPlanosol),NaCl0.1M(a)andCaCl 0.1M(b)treated2
andovendried,showingatypicalilliticstructure(raggedflakes),whichisevenintensifiedincase
ofNaClsaltsolutiontreatment..........................................................................................88
Fig. 5-1 Generated plots of G’ (storage modulus) □ and G”(loss modulus) □. Three stages of
elasticity loss can be defined, showing a gradual transition of an elastic (G’>G”) to a viscous
(G’<G”)character.........................................................................................................101
Fig. 5-2Resultsofconductedamplitudesweeptestswith(distilledwater)saturatedsamplesofa)
Calciudert (andunder pre,drained conditions), Santana do Livramento,b)Sandyandc)Clayey
HapludoxfromCruzAlta,d)ClayeyHapludoxundernaturalforest(F),ande)ClayeyHapludox
undernotillage(NT)conditions,bothfromSantoÂngelo....................................................105
Fig. 5-3Resultsofconductedamplitudesweeptestswithpre,drained(at–60hPa)samplesofa)
Sandy and b) Clayey TypicHapludox from Cruz Alta, c) Clayey TypicHapludox, Santo Ângelo,
under natural forest (F), and d) Clayey Typic Hapludox, Santo Ângelo, under no tillage (NT)
conditions. ..................................................................................................................106
Fig. 5-4Scanningelectronmicrographsofa)SantanadoLivramentoTypicCalciudert,(RioGrande
doSul)RS,untreated;b),d)CruzAlta,RS,sandyTypicHapludox,b)untreated,c)SOMleached,
d)Fe leached;e),g)CruzAlta,RS,clayeyTypicHapludox,e)untreated,f)SOMleached,g)Fe d d
leached;h),j)SantoÂngeloclayeyTypicHapludox,F,h)untreated,i)SOMleached,j)Fe leached;d
k),n) Santo Ângelo, clayey Typic Hapludox, NT, k) untreated, l) SOM leached, m) and n) Fe d
leached,n)detailofm)s.arrow. ...................................................................................108
Fig. A-1 Interaction between a soil particle (idealised) and a tool. a) adsorption water: direct
contact between an air,dried soil particle (without water film); b) molecular water: contact
between a with distilled water saturated or partly (pre,)drained soil particle; menisci may be
formedatthesoilparticle,toolinterface.Inlet:salts(cationsinacertainconcentration)maylead
toachangeofmenisciforces(hydrationmechanisms).c)fieldholdingwater:loosearrangementof
singlegrainswithcontinuouswaterfilm;neitherinternalnorexternalstressisappliedoreffective;
d) gravitational water: particles are surrounded by a continuous water film (saturated), water
menisciareformedatthesoil,toolinterface......................................................................145
Fig. A-2Contactmodelsofsoil,toolinterface:1completelynon,contactingasperitywithoutwater
ring; 2 water,point contacting asperity without water ring; 3 water,ring contacting asperity; 4
water,loopcontactingasperityand5continiuouswaterfilm(redrawnafterJia,2004) .............149
Fig. A-3representativeillustrationofasoilparticle,toolinterface.1and2Initialandrestingstate:
Singleparticlei.e.sandorsiltinrest.3Understeadystressconditions,compressioniscaused;a
convexmeniscishapeisevident.4Underoscillation(betweentoparallelplates)adirectcontact
betweensoilparticleandtoolisgiven;thecontactanglechangesduetooscillatoryshear........150
Fig. B-1Testconfigurationofanamplitudesweeptestwithaconstantfrequencyf=0.5HZ,anda
controlledsheardeformation(CSD)γ=0.0001…100%inoscillation(SoftwareUS200). ...........151
Fig. B-2Datasheetofcollectedparametersinamplitudesweeptest....................................152
Fig. B-3Resultinggraphsfromaconductedamplitudesweeptest.Avarietyofdisplayingstress,
strain relationships is given, based on one database as presented here (see marked data
descriptionontheleftsight“ClayeyOxisol7FFB(S.Angelo)H2Odest.”)...............................152
Fig. B-4Thelinearviscoelasticdeformationrangeiscalculatedautomaticallyaftereachcompleted
testrun,byselectinganappropriatemethod,parameters,andthedataset.Hencetheyieldstress
τ andananaloguedeformationlimitγ derivefromsuchcalculations....................................153 y L
Fig. C-1ModifiedmeasuringplatesystemwithpF,device(perforatedceramicplate).Frontand
backside are shown with interfaces, as well as an additional adapter for filter specimen. (W.
Markgraf,2006)...........................................................................................................154




9Contents



Tables

Tab. 1-1 Rheologyisadisciplineofbothsolidandfluidmechanics,indetailofplasticityandnon,
Newtonianfluids.............................................................................................................14
Tab. 2-1 Synopsisofparametersofrelevanceinrheologyandsoilmechanics,respectively.Further
explanationsaregiveninthetext. ....................................................................................39
Tab. 2-2 Raw data and metrological specifications in oscillatory shear with controlled shear
deformation...................................................................................................................45
Tab. 2-3 Configuration of conducted amplitude sweep tests with controlled shear deformation
(CSD)...........................................................................................................................46
Tab. 2-4 Physical and chemical properties of Ibeco Seal,80, loess from Avdat/Negev Israel,
Vertisol (Bv material), Santana do Livramento/ Escobar and clayey Oxisol, Santo Angelo, Rio
GrandedoSul,Brazil. .....................................................................................................48
Tab. 3-1 Configuration of conducted amplitude sweep tests with controlled shear deformation
(CSD)...........................................................................................................................67
Tab. 3-2PhysicalandchemicalpropertiesofdisturbedsoilmaterialfromHalle(HaplicChernozem)
withthelabelsH1,H7,H15from1,7,and15cmdepth,andKassel(LuvisolonLoess)withKA2,
KA5,KA8,KA15,from2,5,8,and15cmdepth,Germany,andLoessfromAvdat/Negev,Israel..69
Tab. 4-1Physicalandchemicalpropertiesoftheinvestigatedmaterial,Soil03,aCalcaricGleysol,
andSoil04,aDystricPlanosol..........................................................................................83
Tab. 4-2 Summarised collected data of amplitude sweep tests conducted on Soil 03, Calcaric
Gleysol,andSoil04,DystricPlanosol.Foreachtreatmentthreepasseswereabsolved(n=3)....86
Tab. 5-1PhysicochemicalpropertiesofinvestigatedsubstratesfromCruzAlta(sandyandclayey
Typic Hapludox), S. Ângelo (Typic Hapludox F and NT) and Santana do Livramento (Typic
Calciudert). ...................................................................................................................99
Tab. 5-2 Summarized results from conducted amplitude sweep tests (with controlled shear
deformation). Values of γ and τ are arithmetic means, n=3. Generally, under pre,drainedL y
conditionsγ andτ increase,exceptuntreatedclayeyTypicHapludoxsamplesfromSantoÂngelo.L y
Furthermore,adecreaseofγ andτ becomesobvious,ifuntreated,SOMandFe leachedsamplesL y d
arecompared. .............................................................................................................103




















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