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Laboratory Studies Into Undercarriage Systems soil displacement. Yet its relatively narrow width and shallow rut depth resulted in the smallest rut area. Hence, rut depth corresponds more closely with soil compaction. Table 8: Rut parameters for different rear tyres. Treatments followed by different letters are statistically significantly different Treatment Area (m 2 ) Width (m) Depth (m) 500-70/4.5/2.3 0.0333 a 0.56 a 0.093 a 500-85/4.5/1.4 0.0234 b 0.52 b 0.075 b 600/4.5/1.4 0.0298 a 0.61 c 0.077 b 700/4.5/1.0 0.0296 a 0.68 d 0.072 b LSD 0.0037 0.037 0.007 The rut parameters for whole undercarriage systems in Table 9 showed similar characteris- tic as the soil displacement measurement (Section 3.2.2). The cross sectional area split up into two groups and so did the maximum rut depth, too. The width was determined from the initial width of the implement. Table 9: Rut parameters for different undercarriage systems. Treatments followed by different letters are statistically significantly different Treatment Area (m 2 ) Width (m) Max Depth (m) 900/10.5/1.9 followed by 500-70/4.5/2.3 0.0668 a 0.89 a 0.112 a 900/10.5/1.9 followed by 700/4.5/1.0 0.0627 b 0.9 a 0.1 b T3 followed by 500-70/4.5/2.3 0.0401 c 0.67 b 0.09 c T3 followed by 700/4.5/1.0 0.0362 d 0.71 c 0.075 d 680/10.5/2.2 followed by 500-85/4.5/1.4 0.0691 a 0.77 d 0.13 e 680/7/1.6 followed by 500-70/3.5/1.3 followed by 500-85/3.75/1.1 0.0386 c , d 0.65 b 0.08 d 680/7.5/1.5 followed by 680/7.5/1.5 0.0552 e 0.72 c 0.099 b 680/7.5/1.5 followed by 700/4.5/1.0 0.0312 f 0.68 b c 0.065 f 23-11 0.0321 f 0.55 e 0.073 d LSD 0.0037 0.037 0.007 3.2.4 Discussion and Conclusions In general the width and inflation pressure of the tyre determined the amount of soil displacement and thereby soil compaction caused by a tyre. This confirmed the results of An- Ph.D. Thesis Dirk Ansorge (2007) 46
Laboratory Studies Into Undercarriage Systems sorge (2005, a), Antille (2006), and Stranks (2006). Interesting to note was the fact that three of the four tested implement tyres achieved similar results although differing in section width and inflation pressure. An increased section height was able to account for a reduced section width. For whole undercarriage systems the benefit of the tracks shown by Ansorge (2005, a) was maintained after the additional passage of the rear axle tyre. A typical wheeled combine increased the soil density by 19 % compared to a tracked machine with an increase of 14 %. Thereby the effect of the rear axle tyre size had a less effect on soil conditions following a front axle track unit than a tyre. Soil displacement increased by 6 mm compared to 12 mm for the tyre over the same depth range and extended to a shallower depth (300 mm) after the track. This was due to the bearing capacity of the stronger layer in the top 150 mm observed from the penetrometer studies. A hypothetical three axle tyre configuration with 5 t load per tyre caused similar vertical soil displacement compared to a track followed by a rear tyre and to a dual configuration on the front axle. An undercarriage unit with a track unit on the front axle and a gross weight of 33 t resulted in a similar vertical soil displacement to that of an 11 t combine harvester on commercially fitted normal front and rear tyre sizes. A hypothetical 3 axle machine with unequal tyre sizes and load caused intermediate soil compaction compared to that of a tracked and a wheeled machine. An equal weight distribution on two 680-tyres caused nearly as much soil compaction as a traditional wheeled combine configuration on 900 – 700. From this the conclusion can be drawn that a maximum wheel load of 5 t on appropriately inflated tyres has the same impact on soil density changes as the rubber track. Therefore fitting a track on a combine has a similar impact as reducing axle loads to 10 t while using large section width/height tyres and maintaining whole machine weight. Important to note is the residual soil displacement between 500 – 600 mm depth for wheel type undercarriage systems. Soil displacement for track type undercarriage systems has decreased to zero at about 500 – 600 mm depth, but the 680Alt, 680-680, and all common combine harvester tyre combinations maintain a residual soil displacement highlightening their possible impact on the subsoil. The overall configuration of the undercarriage system of the combine harvester was more important than individual weight on a single axle. Ph.D. Thesis Dirk Ansorge (2007) 47
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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
Page 11 and 12: 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 61: 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)
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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
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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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