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Field Study With Full Size Combine Harvesters Figure 62 b) shows the DBD for the experiment on the shallow tilled sandy loam measured with the Troxler. All runs were significantly higher than the control and there were again neither significant differences amongst the controls, nor the runs themselves. In absolute numbers the high inflation pressure tyre experiment caused a 0.004 g/cm 3 higher DBD than the track experiment. This marginal difference was surprising and as the results of the Troxler on clay compared to all the previous parameters showed must be caused by the insensitivity of the method. The tyre at normal inflation pressure had the smallest DBD after the run. Appart from the clay data shown in the previous paragraph this was the only time ever, that a tracked machine caused in tendency more soil compaction than a wheeled machine at normal inflation pressure. This does not agree with all other measured soil physical parameters. The measurements taken in the subsoiled sandy loam showed a significant increase from the control to the measurement taken after the pass of the machinery. There was no significant difference between the controls as can be seen in Figure 62 c). It includes the 95 % CI for the control and the run measurements. The absolute values for the run measurements showed the same tendency as the fishhook method with the lowest density for the track experiment followed by the tyre at normal inflation pressure followed by the high inflation pressure tyre. However, none of these differences were significant. 4.2 Discussion and Conclusion on Field Study The benefit of the rubber tracked machine in comparison to the wheeled machine was shown in field on sandy loam and clay soils with respect to reduced rut depth, soil displacement, and penetrometer resistance. This confirmed the findings from the soil bin laboratory and field study from Ansorge (2005, a) and Chapter 3. The average increase in soil density in the field on both soil types was similar to the one found in the soil bin laboratory study, but reaching only to a more shallow depth. The penetrometer resistances did only show differences on the most pronounced case, the subsoiled sandy loam. On all other occasions the soil was too wet. Interestingly the penetrometer resistance on the sandy loam exhibited a similar pattern after the pass of a wheeled machine on both subsoiled and shallow tilled sandy loam. The tracked machine Ph.D. Thesis Dirk Ansorge (2007) 80
Field Study With Full Size Combine Harvesters was able to maintain penetrometer resistance at a smaller level on the subsoiled part pro- nouncing the ability of the track to maintain loose soil states. The rut parameters showed the clearest picture of all measured parameters. A visual as- sessment of the ruts led to the same conclusion as drawn from rut depth and soil displacement measurement by means of fish hooks. Measuring soil displacement by means of plac- ing fishing hooks into the soil provided a sensible way of measuring soil movement in the field while minimizing initial soil disturbance. Due to the large inherent variation of the data gained with the nuclear density gauge this device proved not to be useful even for assessing relative changes in soil dry bulk density. Therefore the use of this measurement is not recommended. Ph.D. Thesis Dirk Ansorge (2007) 81
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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
Page 45 and 46: Experimental Methods with water and
Page 47 and 48: Experimental Methods 2.4 Statistica
Page 49 and 50: Laboratory Studies Into Undercarria
Page 77 and 78: Field Study With Full Size Combine
Page 95: Field Study With Full Size Combine
Page 99 and 100: Alleviation of Soil Compaction Howe
Page 101 and 102: Alleviation of Soil Compaction not
Page 103 and 104: Alleviation of Soil Compaction in a
Page 105 and 106: Alleviation of Soil Compaction diff
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 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)
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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
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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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