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Soil Compaction Models From Figure 74 a close agreement can be seen between the measured and the predicted increase in soil density for the data from Antille (2006). The accuracy is within an absolute error of +/- 3 %. The linear regression line shows that the increase is underpredicted by 1.5% compared to the 1:1 line, however, linearity of the data is confirmed with an R 2 of 0.95. Depth (mm) Depth (mm) Depth(mm) 0,0 100,0 200,0 300,0 400,0 500,0 600,0 700,0 800,0 0,0 100,0 200,0 300,0 400,0 500,0 600,0 700,0 800,0 Displacement (mm) 0 20 40 60 80 100 120 140 160 180 200 Displacement (mm) 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 80 100 120 140 160 180 200 0,0 100,0 200,0 300,0 400,0 500,0 600,0 700,0 800,0 Dense Dense Dense 900/10.5/1.9 800/10.5/2.5 680/10.5/2.2 Loose Loose Displacement(mm) Loose Figure 73: Measured (■) and predicted (♦) soil displacement for tyres on loose (1.2 g/cm 3 ) and dense (1.6 g/cm 3 ) soil conditions. The least significant differ- ence (LSD) at 95 % is also shown Data from the medium density was used to derive the VCL parameters and it is capable of predicting soil density increase for different initial DBD’s. Thus this justifies the concept of a VCL for a soil at given moisture content in general and in particular for this soil type. Ph.D. Thesis Dirk Ansorge (2007) 110
Soil Compaction Models Predicted Increase (%) 35 30 25 20 15 10 5 0 y = 0,9847x R 2 = 0,9505 0 5 10 15 20 25 30 35 Measured Increase (%) Figure 74: Predicted vs. measured increase in soil displacement for the data from Antille (2006) on dense (1.6 g/cm 3 ) (♦) and loose (1.2 g/cm 3 ) (■) soil. Regression line is dashed and 1:1 relationship solid Moreover the initial DBD from which the in-situ VCL parameters are derived allows a prediction of soil density increase in denser and in looser soil conditions. Thus the in-situ VCL is independent of the initial density it was created for as assumed for general VCLs in theory. The close agreement was achieved with a � of 5 and shows the robustness of the approach against this parameter which technically influences pressure distribution within the soil and is depending on the initial density. The close agreement on higher and lower bearing capacities justifies an extension of the investigation of the capability of the model to predict soil compaction in the more complex cases given below. 6.3.3.2 Stratified Soil Conditions The next step was to compare the performance of the in-situ model for different soil densities within one soil profile. Hence, the stratified soil conditions used by Ansorge (2005, a) were simulated with the in-situ model using densities of 1.45, 1.62, and 1.55 g/cc for the zones: above 200 mm, between 200-325 mm and 325-750 mm, respectively. As can be seen from Figure 75 the predicted and measured soil displacement agree well in shape in- dicating that the compaction behavior of the soil is correctly predicted. However, a general over prediction is visible over the whole depth starting with 14 mm at the surface and de- Ph.D. Thesis Dirk Ansorge (2007) 111
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Cranfield University School of Appl
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Abstract Ancillary experiments show
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Table of Contents TABLE OF CONTENTS
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Table of Contents 4.1.3 Analysis of
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Table of Contents 11.1.1.1 Comparis
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List of Figures and Tables Figure 3
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List of Figures and Tables Figure 1
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Nomenclature NOMENCLATURE Abbreviat
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Introduction 1 INTRODUCTION 1.1 Bac
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Introduction � Ansorge, D. and Go
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Introduction 1.2 Aim To elucidate t
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Introduction a) the soil compaction
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Experimental Methods 2.1.1.1 Test F
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Experimental Methods had been mount
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Experimental Methods track; the loa
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Experimental Methods 800/10.5/2.5 t
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Experimental Methods term. In the m
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Experimental Methods Soil Surface F
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Experimental Methods Depth (cm) 0 1
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Experimental Methods ence surface c
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Experimental Methods chine derives
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Experimental Methods depth. The dat
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Experimental Methods with water and
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Experimental Methods 2.4 Statistica
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Laboratory Studies Into Undercarria
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Page 75 and 76: Laboratory Studies Into Undercarria
Page 77 and 78: Field Study With Full Size Combine
Page 99 and 100: Alleviation of Soil Compaction Howe
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Page 103 and 104: Alleviation of Soil Compaction in a
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Page 107 and 108: Soil Compaction Models sibilities t
Page 109 and 110: Soil Compaction Models depends on t
Page 111 and 112: Soil Compaction Models Wroth (1968)
Page 113 and 114: Soil Compaction Models however, the
Page 115 and 116: Soil Compaction Models level. Criti
Page 117 and 118: Soil Compaction Models Utilizing Ke
Page 119 and 120: Soil Compaction Models average of m
Page 121 and 122: Soil Compaction Models Depth (mm) -
Page 123 and 124: Soil Compaction Models ture content
Page 125: Soil Compaction Models with four ot
Page 129 and 130: Soil Compaction Models Depth (mm) -
Page 131 and 132: Soil Compaction Models and 13.7 % b
Page 133 and 134: Soil Compaction Models Rel. Density
Page 135 and 136: Soil Compaction Models VCL paramete
Page 137 and 138: Soil Compaction Models The approach
Page 139 and 140: Soil Compaction Models surface stay
Page 141 and 142: Soil Compaction Models This result
Page 143 and 144: Soil Compaction Models 6.6.1.3 Wate
Page 145 and 146: Soil Compaction Models σσ 1 (kPA)
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Page 149 and 150: Soil Compaction Models The response
Page 151 and 152: Soil Compaction Models On medium so
Page 153 and 154: Soil Compaction Models SOILFLEX tak
Page 155 and 156: Ancillary Experiments 7 ANCILLARY E
Page 157 and 158: Ancillary Experiments Average conta
Page 159 and 160: Ancillary Experiments In order to c
Page 161 and 162: Ancillary Experiments contrary, the
Page 163 and 164: Ancillary Experiments Figure 102: S
Page 165 and 166: Ancillary Experiments track and the
Page 167 and 168: Ancillary Experiments even when hav
Page 169 and 170: Ancillary Experiments 7.3.2 Influen
Page 171 and 172: Ancillary Experiments The results f
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Page 175 and 176: Ancillary Experiments Contact Press
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Ancillary Experiments Figure 123: F
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Ancillary Experiments Sinkage (mm)
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Ancillary Experiments model which o
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Ancillary Experiments 7.3.5 The Inf
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Ancillary Experiments 7.3.7 Discuss
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Ancillary Experiments Terzaghi (194
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Ancillary Experiments contact area.
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Ancillary Experiments soil forward
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Conclusions � The longitudinal so
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Bibliography 10 BIBLIOGRAPHY Aboaba
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Bibliography Defossez, P., Richard,
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Bibliography Gregory, A.S.; Whalley
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Bibliography Lamande, M., Schjonnin
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Bibliography Seig, D., 1985. Soil C
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Appendix 11 APPENDIX Ph.D. Thesis D
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Appendix Figure 32: VCL sample at t
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Appendix comparison at the deepest
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Appendix Estimated Pressure (kPa) 2
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Appendix 11.1.1.2.1 SOCOMO One of t
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Appendix by Seig (1985) who showed
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Appendix Soil water content 15 % an
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Appendix Adapting critical state so
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Appendix density is obtained by add
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Appendix Table 5: Values of constan
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Appendix choice of a concentration
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Appendix 11.1.3.1 Dense/Hard and Lo
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Appendix 11.1.3.2 Stratified Soil C
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Appendix To summarize the ability t
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Appendix In the following the predi
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Appendix concentration factor of 4,
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Appendix 11.1.5.1 Confining Pressur
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Appendix Figure 24. The VCL created
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Appendix Rel. Density 2 1,9 1,8 1,7
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Appendix relation of � 1 to � 2
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Appendix Rel. Density 2 1,9 1,8 1,7
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Appendix Rel. Density 1,7 1,68 1,66
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Appendix Depth (mm) 0,0 100,0 200,0
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Appendix Figure 42: Plate in cookin
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Appendix � z � � �� k c p
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Appendix Table 8: n and k depending
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Appendix to the plate sinkage equat
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Appendix with a slight deviation fr
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Appendix Table 12: DBD values for a
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