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Appendix impact at the surface was ignored due to settlement as explained later. For the maximum working depth of 350 mm a uniform DBD of 1.49 g/cm 3 was assumed. Below 350 mm it was similar to before with 1.6 g/cm 3 to 750 mm. Starting with the sandy loam which received the shallow disc tine cultivation an offset of 15 mm was taken out similar to the clay as both soils received the same cultivation. As obvious from Figure 19 predicted soil displacement is larger for a concentration factor of 5 compared to a concentration factor of 4. The influence of the actual pressure calculation when soil displacement is calculated in the model is marginal, however, the influence of the concentration factor on the slope and intercept of the VCL causes this difference. Overall a concentration factor of 4 fits better, however, using the VCL created in the soil bin on the same soil type with a concentration factor of 5 fits the data best. This is due to the fact that the VCL from the soil bin contains more data points. The field experiment was conducted at a moisture content of approximately 20 % whereby the soil bin experiment was conducted at about 9 %. The good agreement in predicted soil displacement using the soil bin VCL is due to a similar distance from optimum moisture content for compaction which is at about 15 % moisture content for a sandy loam soil. Taking the three different VCLs into consideration which were used to predict soil displacement and created from tyre passes only on shallow tilled soil, only subsoiled soil and the pooled one, shows the best agreement for the VCL prediction gained from the shallow tilled plot only. Using the one gained from the subsoiled plot estimates soil displacement higher and the pooled one (called “both”) predicts intermediate soil displacement. The three different VCLs are shown in Figure 20. Predicted vs. measured data for the sandy loam soil subsoiled is shown in Figure 21. A concentration factor of 4 fits the data for the normal inflation pressure better than a concentration factor of 5. However, at high inflation pressure a concentration factor of 5 seems more appropriate because it overcomes the under estimated soil displacement for this passage. Thus on this soil condition no clear recommendation can be given concerning the concentration factor. Similar to the shallow tilled part the VCL gained from the soil bin gives the best estimation of soil displacement. Interesting to note is the relation between the estimation gained from the pooled data (“both”) and the one only utilizing the data gained on the subsoiled plot (“subsoil”). At a concentration factor of 5, the prediction for “both” is bigger than for “subsoil” at normal and high inflation pressure. Nevertheless at a Ph.D. Thesis Dirk Ansorge (2007) 217
Appendix concentration factor of 4, “subsoil” is bigger than “both” as expected from previous results on the shallow tilled soil. Depth (mm) -10 0 10 20 30 40 50 60 70 80 -10 0 10 20 30 40 50 60 70 80 -100 -100 0 10 0 20 0 30 0 40 0 50 0 60 0 70 0 5 Both 5 Subsoil 4 Both 4 Subsoil 5 Shallow 4 Shallow Soil Bin VCL -10 0 10 20 30 40 50 60 70 80 -10 0 10 20 30 40 50 60 70 80 Displacement (mm) Depth (mm) 100 200 300 400 500 600 700 Ph.D. Thesis Dirk Ansorge (2007) 0 Displacement (mm) 5 Both 5 Subsoil 4 Both 4 Subsoil 5 Shallow 4 Shallow Soil Bin VCL Figure 19: Measured (points) and predicted (lines) soil displacement for the normal Rel. Density 3 2,5 2 1,5 1 (2.5 bar) (left hand side) and high inflation pressure (3.5 bar) (right hand side) treatment on shallow tilled sandy loam soil Rel. Density 3 2,5 2 1,5 1 0,5 y = -0,2682Ln(x) + 2,6601 R 2 = 0,9999 y = -0,2628Ln(x)+ 2,6601 R 2 = 0,9999 0 y= -0,2592Ln(x) +2,6586 R 2 =0,996 y= -0,2542Ln(x) +2,6587 R 2 = 0,9961 Sandy Loam Subsoiled and Shallow Tilled 1 10 100 Subsoiled 0,5 0 Conc=4 1 10 100 Pressure(kPa) Conc = 5 Pressure (kPa) Rel. Density Conc = 5 Conc=4 Logarithmisch(Conc =5) 3 2,5 2 1,5 1 0,5 0 y = -0,2471Ln(x) + 2,6606 R y = -0,2519Ln(x) + 2,6606 2 = 0,998 R 2 = 0,998 Shallow Tilled 1 10 100 Pressure (kPa) Conc=5 Conc=4 Figure 20: Virgin compression lines from different grouping of field experiments on sandy loam soil 218
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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
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Soil Compaction Models level. Criti
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Soil Compaction Models Utilizing Ke
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Soil Compaction Models average of m
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Soil Compaction Models Depth (mm) -
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Soil Compaction Models ture content
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Soil Compaction Models with four ot
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Soil Compaction Models Predicted In
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Soil Compaction Models Depth (mm) -
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Soil Compaction Models and 13.7 % b
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Soil Compaction Models Rel. Density
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Soil Compaction Models VCL paramete
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Soil Compaction Models The approach
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Soil Compaction Models surface stay
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Soil Compaction Models This result
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Soil Compaction Models 6.6.1.3 Wate
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Soil Compaction Models σσ 1 (kPA)
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Soil Compaction Models pressure to
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Soil Compaction Models The response
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Soil Compaction Models On medium so
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Soil Compaction Models SOILFLEX tak
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Ancillary Experiments 7 ANCILLARY E
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Ancillary Experiments Average conta
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Ancillary Experiments In order to c
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Ancillary Experiments contrary, the
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Ancillary Experiments Figure 102: S
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Ancillary Experiments track and the
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Ancillary Experiments even when hav
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Ancillary Experiments 7.3.2 Influen
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Ancillary Experiments The results f
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Ancillary Experiments Figure 117: S
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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
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
Page 217 and 218: Appendix Soil water content 15 % an
Page 219 and 220: Appendix Adapting critical state so
Page 221 and 222: Appendix density is obtained by add
Page 223 and 224: Appendix Table 5: Values of constan
Page 225 and 226: Appendix choice of a concentration
Page 227 and 228: Appendix 11.1.3.1 Dense/Hard and Lo
Page 229 and 230: Appendix 11.1.3.2 Stratified Soil C
Page 231 and 232: Appendix To summarize the ability t
Page 233: Appendix In the following the predi
Page 237 and 238: Appendix 11.1.5.1 Confining Pressur
Page 239 and 240: Appendix Figure 24. The VCL created
Page 241 and 242: Appendix Rel. Density 2 1,9 1,8 1,7
Page 243 and 244: Appendix relation of � 1 to � 2
Page 245 and 246: Appendix Rel. Density 2 1,9 1,8 1,7
Page 247 and 248: Appendix Rel. Density 1,7 1,68 1,66
Page 249 and 250: Appendix Depth (mm) 0,0 100,0 200,0
Page 251 and 252: Appendix Figure 42: Plate in cookin
Page 253 and 254: Appendix � z � � �� k c p
Page 255 and 256: Appendix Table 8: n and k depending
Page 257 and 258: Appendix to the plate sinkage equat
Page 259 and 260: Appendix with a slight deviation fr
Page 261: Appendix Table 12: DBD values for a
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