On the consolidation behaviour of fine-grained soils under ...
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On the consolidation behaviour of fine-grained soils under cyclic loading DISSERTATION zur Erlangung des akademischen Grades Doktor-Ingenieur (Dr .-Ing.) an der Fakultät für Bau- und U mweltingenieurwissenschafteu der Ruhr- Un ivers it ät Bochum vorgelegt von Nina Silvia Müthing geboren am 14. Februar 1987 in Essen Ha.11ptherichter: Univ. Prof. Dr.-lng. h ab il. Tom Sduu1z l\:fit.hcrichter: Prof. Dr. Maria Datch cva. l\Iithcrichter: Chaucellor 's Professor Kenichi Soga, PhD FREng FICE l\IitlJf'riditer: Univ. Prof. Dr.-lng. h ab il. T heod oros Triantafyllidis Bochum, November 20 17
Transcript of On the consolidation behaviour of fine-grained soils under ...
On the consolidation behaviour of fine-grained soils under cyclic loading
DISSERTATION
zur Erlangung des akademischen Grades
Doktor-Ingenieur (Dr .-Ing.)
an der
Fakultät für Bau- und U mweltingenieurwissenschafteu
der Ruhr-Universität Bochum
vorgelegt von
Nina Silvia Müthing
geboren am 14. Februar 1987 in Essen
Ha.11ptherichter: Univ. Prof. Dr.-lng. habil. Tom Sduu1z
l\:fit.hcrichter: Prof. Dr. Maria Datchcva.
l\Iithcrichter: Chaucellor's Professor Kenichi Soga, PhD FREng FICE
l\IitlJf'riditer: Univ. Prof. Dr.-lng. habil. T heodoros Triantafyllidis
Bochum, November 2017
Contents
1 lntroduction
1.1 Motivation .
1.2 Objectives .
1.3 Layout of the thesis .
2 Compressibility and permeability of fine-grained soils
2.1 Soil structure ...
2.1.1 Clay fabric.
2.1.2 Methods for clay fabric investigat ion
2.1.3 States of clay structure ....
2.2 One-dimensional compression of soils
2.2.1 Laboratory determination . .
2.2.2 Primary compression of fine-grained soils
2.2.3 Primary compression of natural, structured clay
2.2.4 Barotropy and pycnotropy
2.2.5 Historiotropy .....
2.2.6 Secondary compression
2.2. 7 Rate dependency . . .
2.2.8 Temperature dependency .
2.2.9 Development of horizontal stress .
2.3 Permeability of fine-grained soils .
2.3.1 Darcy's law ....... .
2.3.2 Permeability of soils . . .
2.3.3 Hydraulic permeability of clays
2.3.4 Laboratory measurement .
2.3.5 Anisotropy .
2.4 Summary . . . . .
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3 Consolidation of fine-grained soils
3.1 Introduction ....... .
3.2 Principle of effective stress
3.3 One-dimensional, linear consolidation theory
3.3.l General theory of consolidation - Biot model
3.3.2 Hybrid model . . . . . . . . . . . . . . . . .
3.3.3 Terzaghi model . . . . . . . . . . . . . . . .
3.4 Analytical solution for one-dimensional, linear consolidation
3.4.1 Initial and boundary conditions
3.4.2 Pore water pressure u . .. .
3.4.3 Settlement s ..... ... .
3.4.4 Degree of consolidation Um .
3.4.5 Dimensionless consolidation time Tv .
3.4.6 Coefficient of consolidation Cv . . . .
3.5 Multi-dimensional and non-linear consolidation
3.5.1 Multi-dimensional consolidation ..
3.5.2 Non-linear constitutive approaches
3.5.3 Further enhancements in consolidation theory
3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . .
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4 Consolidation under cyclic loading 47
4.1 Mathematical approaches in literature . . . . . . . . . . . . . . . . . . . . 47
4.2 Analytical solution for consolidation under cyclic loading of haversine form 48
4.2.1 Pore water pressure u . ..
4.2.2 Settlement s . . . . . . . .
4.3 Experimental studies in literature
4.4 Summary ............ .
5 Oedometer device
5.1 Introduction ..
5.2 Design and construction
5.2.1
5.2.2
5.2.3
General construction
Vertical stress and deformation measurement .
Oedometer ring and radial stress measurement .
5.2.4 Drainage system and pore pressure measurement
5.3 Calibration ......... .
5.3.1 Calibration with steel .
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5.3.2 Calibration with water
5.3.3 Calibration with clay
5.4 Summary . . . . . .
6 Materialsand methods
6.1 Materials
6.1.1 General
6.1.2 Spergau kaolin clay
6.1.3 Ons0y clay .....
6.1.4 Summary of material properties of studied clays
6.2 Experimental p:i;ogramme . . . . . .
6.2.l Monotonie oedometer tests .
6.2.2 Cyclic oedometer tests ...
6.3 Sample preparation and testing procedure
6.3.1 Soil material preparation .
6.3.2 Sample installation ..
6.3.3 Installation procedure
6.4 Summary . . . . . . . . . . .
7 Experimental study on consolidation under monotonic loading
7.1 Deformation behaviour ................. .
7 .1.1 General one-dimensional compression behaviour
7.1.2 Friction ....... . . .
7 .1.3 Consolidation settlements
7.1.4 Coefficient of consolidation Cv
7 .1.5 Development of stiffness and permeability
7.1.6 Secondary compression ..
7.2 Pore water pressure dissipation
7.3 Comparison to analytical solution
7.4 Development of radial stress
7.5 Summary . . . . . . . . . .
8 Experimental study on cyclic consolidation
8.1 Introduction .
8.2 Friction . . .
8.3 Cyclic deformation behaviour
8.3.1 General ....... .
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8.3.3
8.3.4
8.3.5
8.3.6
8.3.7
Final mean deformation e55 • •
Rate of consolidation . . . . .
Amplitude of deformation ~e
Development of equivalent stiffness Es Permeability from cyclic Cv and equivalent stiffness
Deformation in the stationary state . . . . . . . . .
8.4 Cyclic pore water pressure dissipation .. . . . .. .. .. .
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8.4.1 Maximum pore water pressure and rate of pore water pressure dis-
sipation . . . . . . . . . . . 165
8.4.2 Pore pressure amplitude ~u 167
8.5 Cyclic stress-strain behaviour . . 169
8.6 Comparison to analytical solution 170
8. 7 N umerical modelling . . . . . . . 175
8. 7.1 Verification of the analytical solution by linear-elastic FEA 175
8.7.2 Numerical analysis using hierarchical, constitutive models . 176
8.7.3 Conclusions .....
8.8 Development of radial stress
8.9 Summary and discussion ..
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9 Phase shift in cyclic consolidation 187
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9.1 Introduction .......... .
9.2 Analytical solution from consolidation equation
9.3 State of the art - Phase shift in conduction phenomena
9.4 Experimental analysis . . ......... .
9.4.1 Phase shift of deformation '!/Je ... . 9.4.2 Phase shift of pore water pressure 'l/Ju 9.4.3 Comparison t0 analytical solution . .
9.5 Testing concept: from phase shift to material characteristics
9.5.1 Motivation . . . ... ..... ... ... .
9.5.2 Suggested concept and validation strategy
9.6 Summary ...... .
10 Summary and conclusions
10.1 Conclusions . . . . . .
10.2 Recommendations for further studies
References
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