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Ancillary Experiments Figure 107: Lug influence close to the centre of a rut on stratified soil conditions after the pass of a 900/10.5/1.9 The conclusion can be drawn that soil displacement caused by lugs did not exceed the working depth of a weak uniform soil condition, i.e. it does not affect soil displacement significantly to a depth where it could not be alleviated with common tillage operations. Soil pressure measurements might indicate higher pressures due to the higher pressure caused by the lug on the soil (Gupta and Raper, 1994 and Way et al., 1993), but this pressure peak did not cause the soil to additionally deform to a critical depth. At the surface lug influence decreases when the distance to the centre of the rut decreases where the actual soil displacement is highest. 7.3 Introduction of a new Variable - Load per Perimeter Length The following Section evolved empirically from a study relating soil density increase to contact pressure and aiming to account for the obvious variations as best as possible. 7.3.1 General Problems with Contact Pressure and First Considerations When considering soil density increase depending on contact pressure some variation is obvious as visible in Figure 108 whereby plotting the average soil deformation caused by a single tyre or track treatment against its mathematical average contact pressure does not result in a smooth relationship. Taking the axle load into account shows that the higher axle load (quadrats) is always higher in soil deformation than the lower axle load (circles), Ph.D. Thesis Dirk Ansorge (2007) 150
Ancillary Experiments even when having a similar contact pressure. This supports the results from Lamande et al. (2006) based on the original theory from Söhne (1954) stating that the higher the load the more stress and consequently soil deformation is caused over the entire soil profile even if the contact pressure is the same. Soil Deformation (1/100 * % Increase in DBD) 0,18 D C 0,16 0,14 0,12 0,10 0,08 0,06 A B 60 80 100 120 140 160 180 Contact Pressure (kPa) High Axle Load Low Axle Load Figure 108: Soil deformation vs. contact pressure for tyre and track treatments However, the theory from Söhne does not provide an explanation for the large deviations within a group of axle loading. Going from point A in Figure 108 to point B contact pressure increases from 70 kPa to 80 kPa, respectively 14.2 %. The corresponding soil deformation increases from 0.124 to 0.134, 8 % respectively. When looking at point C and D, contact pressure increases from 112 kPa to 152 kPa, 35.7%. Taking the previous comparison into account soil deformation should increase by approximately half, which is 15 - 20 %. Interestingly soil deformation only increases by 2.3 % from 17.3 to 17.7 %. There is no obvious explanation for the deviation of soil deformation with an increased contact pressure. It might possibly be a diminishing rate of increase; however, considering the contact pressures of the low axle loads, no such diminishing rate is visible although reach into the same contact pressure range. To investigate the cause of the large scatter of data points, load was plotted against soil deformation. As can be seen from Figure 109 low axle loads can cause similar soil deformation as high axle loads. Per se there is no differ- ence in soil deformation at different axle loads. Ph.D. Thesis Dirk Ansorge (2007) 151
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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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Field Study With Full Size Combine
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Alleviation of Soil Compaction Howe
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Alleviation of Soil Compaction not
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Alleviation of Soil Compaction in a
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Alleviation of Soil Compaction diff
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Soil Compaction Models sibilities t
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Soil Compaction Models depends on t
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Soil Compaction Models Wroth (1968)
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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 and 126: Soil Compaction Models with four ot
Page 127 and 128: Soil Compaction Models Predicted In
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)
Page 147 and 148: Soil Compaction Models pressure to
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: Ancillary Experiments track and the
Page 169 and 170: Ancillary Experiments 7.3.2 Influen
Page 171 and 172: Ancillary Experiments The results f
Page 173 and 174: Ancillary Experiments Figure 117: S
Page 175 and 176: Ancillary Experiments Contact Press
Page 177 and 178: Ancillary Experiments Figure 123: F
Page 179 and 180: Ancillary Experiments Sinkage (mm)
Page 181 and 182: Ancillary Experiments model which o
Page 183 and 184: Ancillary Experiments 7.3.5 The Inf
Page 185 and 186: Ancillary Experiments 7.3.7 Discuss
Page 187 and 188: Ancillary Experiments Terzaghi (194
Page 189 and 190: Ancillary Experiments contact area.
Page 191 and 192: Ancillary Experiments soil forward
Page 193 and 194: Conclusions � The longitudinal so
Page 195 and 196: Bibliography 10 BIBLIOGRAPHY Aboaba
Page 197 and 198: Bibliography Defossez, P., Richard,
Page 199 and 200: Bibliography Gregory, A.S.; Whalley
Page 201 and 202: Bibliography Lamande, M., Schjonnin
Page 203 and 204: Bibliography Seig, D., 1985. Soil C
Page 205 and 206: Appendix 11 APPENDIX Ph.D. Thesis D
Page 207 and 208: Appendix Figure 32: VCL sample at t
Page 209 and 210: Appendix comparison at the deepest
Page 211 and 212: Appendix Estimated Pressure (kPa) 2
Page 213 and 214: Appendix 11.1.1.2.1 SOCOMO One of t
Page 215 and 216: 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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