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Laboratory Studies Into Undercarriage Systems 3.3 Track Studies The benefits found for TerraTracs by Ansorge (2005, a) raised the question how different belt tensions influence soil physical properties, i.e. what benefit could be gained from higher tension and what damage might be caused by less tension. Additionally of interest became how different track types compare to the TerraTrac. Thus, in a first instance the rubber belt tension was evaluated and in the second part, different track type units were evaluated. Additionally to penetrometer resistance, soil displacement, and rut characteris- tics, longitudinal pressure profiles described in Section 2.2.5 were measured for these treat- ments. 3.3.1 Evaluation of the Effect of Rubber Belt Tension This section aims at evaluating the influence of belt tension in the Claas TerraTrac system on soil physical properties. Therefore the three idler Claas Terra Trac unit was run at a higher belt tension of 200 bar (20 t belt tension) and at a lower belt tension of 50 bar (5 t belt tension) whereby results were compared to the data gained at the common pressure of 160 bar (16 t belt tension) from Ansorge (2005, a). A belt pressure of 160 bar is necessary for the TerraTrac as it is friction driven and hence relies on belt tension to develop draught. 3.3.1.1 Penetrometer Resistance Penetrometer resistance for the TerraTrac at the three belt pressures is shown in Figure 36. There is a trend that shows that the peak penetrometer resistance reduces with increasing tension. In tendency the unit at 50 bar created the highest peak in penetrometer resistance close to the surface and its decrease in penetrometer resistance with depth was smaller than for higher pressures. At 200 bar the peak at the surface was smallest and therefore the penetrometer resistance at depth marginally smaller. However, taking the entire curves into consideration, no significant differences were found. Ph.D. Thesis Dirk Ansorge (2007) 48
Laboratory Studies Into Undercarriage Systems Depth (mm) 0 100 200 300 400 500 600 700 800 Penetration Res is tance (MPa) 0 0,5 1 1,5 2 2,5 Control 160 bar 200 bar 50 bar LSD at 95% CI Figure 36: Penetrometer resistance vs. depth for the Claas unit at three belt pressures 3.3.1.2 Soil Displacement Soil displacement for the normal belt tension at 160 bar in Figure 37 showed a larger soil displacement than both the 50 and 200 bar experiment and was statistically significantly different from the unit at 200 bar (p=0.0059). The soil displacement data for the belt tension at 160 bar originates from Ansorge (2005, a). Hence, the difference in soil displacement is most likely due to both the variation in soil bin preparation due to possible changes on the soil processor and this particular run of the track at 12 t from Ansorge (2005, a) be- ing an outlier showing more soil displacement, too. The penetrometer resistance given ear- lier in Section 3.3.1.1 for the experiment at 160 bar originates from this study and conse- quently was in line. The talcum powder lines for this particular experiment were used al- ternatively to evaluate the influence of lugs on vertical soil displacement as detailed in Sec- tion 7.2. When the unit was operated at 200 bar, it caused the least soil displacement. At 50 bar, rut depth and soil displacement were larger, but no statistical difference could be de- tected. Over the entire depth soil displacement for the unit at 50 bar varied slightly, however, was always bigger than the soil displacement at 200 bar. Ph.D. Thesis Dirk Ansorge (2007) 49
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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
Page 13 and 14: List of Figures and Tables Figure 1
Page 15 and 16: Nomenclature NOMENCLATURE Abbreviat
Page 17 and 18: Introduction 1 INTRODUCTION 1.1 Bac
Page 19 and 20: Introduction � Ansorge, D. and Go
Page 21 and 22: Introduction 1.2 Aim To elucidate t
Page 23 and 24: Introduction a) the soil compaction
Page 25 and 26: Experimental Methods 2.1.1.1 Test F
Page 27 and 28: Experimental Methods had been mount
Page 29 and 30: Experimental Methods track; the loa
Page 31 and 32: Experimental Methods 800/10.5/2.5 t
Page 33 and 34: Experimental Methods term. In the m
Page 35 and 36: Experimental Methods Soil Surface F
Page 37 and 38: Experimental Methods Depth (cm) 0 1
Page 39 and 40: Experimental Methods ence surface c
Page 41 and 42: Experimental Methods chine derives
Page 43 and 44: 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 63: Laboratory Studies Into Undercarria
Page 77 and 78: 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
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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
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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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