0 the rolling resistance of articulated dump trucks on haul roads

364 Pages·2015·13.08 MB·English

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THE ROLLING RESISTANCE OF ARTICULATED DUMP TRUCKS ON
HAUL ROADS
GRAEME SCOTT WOOD (B.Eng.)
THESIS SUBMITTED To THE UNIVERSITY OF EDINBURGH FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
1994
DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING
UNIVERSITY OF EDINBURGH
Declaration
I declare that this thesis was written by me, and that the work described was
carried out by myself unless otherwise acknowledged.
The accurate estimation of velocity of articulated dump trucks has been a problem
to highway engineers for a long time. The literature published by agricultural,
military, and civil engineers, on the subject of rolling resistance has been critically
examined. This review indicated that no practical means has been established for
predicting the performance of this type of vehicle with respect to classical soil
mechanics. A two-dimensional model has been developed, based on classical soil
mechanics theory, enabling the rut depth on a haul road to be estimated from the
information contained in the site investigation report.
A large amout of site monitoring was undertaken on chalk and clay haul roads, the
findings of which were compared with the theoretical model. The results were also
used to develop equations relating rolling resistance to the various soil and physical
parameters. Reasons for discrepancies between the measured results and the
theoretical estimation were investigated. A subsequent theory regarding the
deterioration of the haul roads in terms of effective stress is presented, backed up
with experimental data. Practical remedies for haul road deterioration problems are
also discussed.
11
The author wishes to thank Professor M.C. Forde, Head of the Department of
Civil and Environmental Engineering at the University of Edinburgh for placing
the departmental facilities at his disposal. The author is also grateful to Professor
M.C. Forde for his supervision, encouragement and constructive criticism
throughout the duration of the project. The contributions of Dr. D.A. Ponniah as a
second supervisor, and Mr. J.R. Osborne, of Tarmac Construction Ltd., as
industrial sponsor, are also gratefully acknowledged.
The author would like to thank the following fellow students for their helpful
discussions and assistance: Dr. C.A. Fairfield, now at the Department of Civil and
Transportation Engineering, Napier University, for many long and fruitful
discussions on the behaviour of soils, Messrs. Dunn, and Smith, of Tarmac and the
University of Edinburgh, for their assistance in taking site readings, observations,
and knowledge of earthmoving operations, and Mr. C. Lambton, formally at the
University of Edinburgh, for site, laboratory, and mental assistance. The help from
all the site personnel that were involved in the project is also acknowledged.
Thanks are due to the technical staff of the Department of Civil and Environmental
Engineering, particularly Mr. I. Fowler, and Mr. R. Paton, at the Department of
Civil and Transportation Engineering, Napier University, for their invaluable
assistance. Thanks also go to Mr G. Brown and Mr. F. Johnston for the
preparation of the photographic material.
The author wishes to thank Ms. M. Foley for her help, patience, encouragement
and for reading the manuscript. He is also indebted to his parents and brother for
their continual support, and to his colleagues in the Department of Civil and
Environmental Engineering for their sociability and friendship.
The financial support for this work has been provided by the Science and
Engineering Research Council, Case Award No. 91564505, and Tarmac
Construction Ltd., Wolverhampton, and is gratefully acknowledged.
111
The text is divided into chapters and sections. Sections are numbered decimally
within each chapter; the number given to figures indicate to which chapter they
belong, but are not related to the section numbers. Figures, tables, and plates are
situated at the end of each chapter and are in the order noted above.
Declaration (cid:9) 1

Abstract

Acknowledgements
iv
Table of Contents (cid:9)
ix
Notation (cid:9)
Chapter 1 (cid:9) Introduction (cid:9) 1
Chapter 2 Literature Survey
2.1 Introduction 5
2.2 Definitions of Wheel and Tyre 6
2.3 Properties of Pneumatic Tyres 7
2.4 Rolling Resistance Forces 7
2.5 Plate Sinkage Techniques 8
2.5.1 (cid:9) The Work of Bernstein 8
2.5.2 The Work of Bekker 9
2.5.3 (cid:9) Load Penetration Relationship 14
2.5.4 (cid:9) The Horizontal Shear Relationship 16
2.5.5 (cid:9) Discussion 17
2.6 The Work of Reece 17
2.7 The Work of Onafeko and Reece 18
2.8 The Work of Gee-Clough 20
2.9 British Theory for Clay 22
2.9.1 (cid:9) The Work of Micklethwaite 22
iv
2.10 The Work of Uffelmann 23
2.11 The Work of Heatherington et al. 26
2.12 Finite Element Method 27
2.13 Empirical Techniques 27
2.13.1 Direct Measurement of Vehicle Parameters 28
2.13.2 Work at the National Institute of Agricultural
Engineers (N.I.A.E.) 29
2.13.3 The Cone Penetrometer 30
2.13.4 Mobility Number Methods 32
2.13.5 Amendments to the Mobility Number Equations
with Respect to Rolling Resistance Estimation 33
2.13.6 Problems with the Cone Penetrometer and Mobility
Numbers 37
2.13.7 Discussion on the Cone Penetrometer 38
2.14 Work Carried out by Civil Engineers into Earthmoving 38
2.14.1 The Work of Norman 39
2.14.2 Work Carried out at the Transport Research
Laboratory (TRL) 40
2.15 Discussion 44
Chapter 3 Rolling Resistance
3.1 Introduction 63
3.2 Definition of Rolling Resistance 63
3.3 Specification Sheets 66
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3.4 Computer Programs 68
3.4.1 (cid:9) Vehsim 68
3.4.2 (cid:9) Accelerator 70
3.5 Comparison of the Three Methods of Estimating Velocity 71
3.6 Effect of Mass on the Velocity versus Rolling Resistance
Relationship 72
3.7 Summary 73
V
Chapter 4 Chalk
4.1 Introduction 83
4.2 Properties of Chalk 84
4.3 Classification of Chalk 85
4.4 Problems on the Haul Roads 87
4.4.1 (cid:9) Deterioration of the Ramps Between Benches 88
4.4.2 (cid:9) Deterioration due to Manoeuvring 90
4.4.3 (cid:9) Other Problem Areas 91
4.5 Monitoring 92
4.6 Rolling Resistance and Site Results 94
4.7 Analysis of Smoothing the Gradients 97
4.8 Effects of Plant Mixing 98
4.9 Conclusions 99
Chapter -5 (cid:9) Clay Site
5.1 Introduction 117
5.2 Description of Soil from Site Investigation Report 117
5.3 Quality of Haul Roads 117
5.4 Site Monitoring 118
5.5 Laboratory Soils Testing 119
5.5.1 (cid:9) Classification Tests 119
5.5.2 (cid:9) Multistage Undrained Triaxial Shear Tests 119
5.6 Site Testing and Results in Relation to Rolling Resistance 122
5.6.1 (cid:9) Grade Resistance versus Velocity and Rolling
Resistance 122
5.6.2 (cid:9) Moisture Condition Value versus Rolling
Resistance 124
5.6.3 (cid:9) Notes on the Moisture Condition Value Test 126
5.6.4 (cid:9) Cone Index versus Rolling Resistance 128
5.6.5 (cid:9) Hand Vane Shear versus Rolling Resistance 128
5.6.6(cid:9) Consistency Index versus Rolling Resistance 130
5.6.7 (cid:9) Rut Depth versus Rolling Resistance 133
134
5.7 Regression Analysis
5.7.1 (cid:9) Theory 134
vi
5.7.2 (cid:9) Residuals 137
5.7.3 (cid:9) Confidence and Prediction Intervals 137
5.7.4 (cid:9) Analysis 139
5.7.5 (cid:9) Validation of Regression Equations 141
5.8 Summary 142
Chapter 6 Development of Theory of Rolling Resistance
6.1 Introduction 194
6.2 Fundamental Relationships 194
6.3 Pressure Distribution Beneath Pneumatic Tyres 195
6.3.1 (cid:9) Review of Pressure Distribution Literature 196
6.4 Caterpillar Relationship Between Rut Depth and Rolling
Resistance 201
6.5 Spreadsheet Analysis 202
6.5.1 (cid:9) Input Parameters 202
6.5.2 (cid:9) Contact Area 203
6.5.3 (cid:9) Shear Strength 204
6.5.4 (cid:9) Rolling Resistance 204
6.5.5 (cid:9) Amending the Theory 205
6.6 Comparison of Theory with Measured Rut Depths 205
6.7 Comparison Between Rut Depth and Consistency Index 206
6.8 Sensitivity Analysis 207
6.8.1 (cid:9) Introduction 207
6.8.2 (cid:9) 2k Factorial Design 207
6.8.3 (cid:9) Effect on Rolling Resistance Using 2k Factorial
Design 208
6.9 Summary 212
Chapter 7 Investigation Into the Effect of Pore Water Pressure Increase
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7.1 Introduction 237
7.2 Theory 238
7.3 Experimental Verification 240
7.3.1 (cid:9) Test Material 240
7.3.2 (cid:9) Test Apparatus 240
vii
(cid:9)(cid:9)
7.3.3 Pore Water Pressure Measurement (cid:9) 241
7.3.4 Test Procedure (cid:9) 241
7.4 (cid:9) Experimental Results (cid:9) 242
7.5 (cid:9) Discussion (cid:9) 244
Chapter 8 Conclusions
8-.1 Overall Conclusion 258
258
8.2 Literature
8.3 Empirical Rolling Resistance 258
8.4 Site Monitoring 259
8.4.1 (cid:9) Chalk 259
8.4.2 (cid:9) Clay 260
8.5 General Observations of Site Practice 260
8.6 Rut Depth Theory 260
8.7 Pore Water Pressure Increase 261
Chapter 9 Recommendations for Future Work
9.1 (cid:9) Predicting Rolling Resistance (cid:9) 262
9.2 (cid:9) Other Site Considerations (cid:9) 262
9.3 (cid:9) Materials Testing (cid:9) 263
9.4 Recommendations for Industry (cid:9) 263
264
References (cid:9)
Appendix 1 Publications
Al. 1 Published Papers (cid:9) 282
A1.2 Papers Accepted for Publication (cid:9) 292
A1.3 Papers Currently being Refereed (cid:9) 308
Appendix (cid:9) Site Monitoring Procedure (cid:9) 350
Appendix 3 Tabulated Results (cid:9) 352
viii
Notation
a (cid:9) constant
a (cid:9) regression coefficient
a graphical intercept
n (cid:9)
B (cid:9) modulus of deformation due to the cohesive component of the soil
B (cid:9) number of blows in MCV test
b (cid:9) regression coefficient
b (cid:9) width of running gear
C (cid:9) cone index
C (cid:9) modulus of deformation due to the frictional component of the soil
coefficient of rolling resistance
CRR (cid:9)
c (cid:9) apparent soil cohesion
(cid:9) apparent cohesion in terms of effective stress
I
c undrained shear strength
u (cid:9)
d (cid:9) soil deformation
d (cid:9) wheel diameter
DP (cid:9) drawbar pull
en (cid:9) average effect of factor n
fitted y calculated response
g (cid:9) acceleration due to gravity
G(cid:9) cone index gradient
G (cid:9) grade resistance
GVW gross vehicle weight
h (cid:9) tyre section height
H (cid:9) forward thrust
H (cid:9) gross tractive effort
H (cid:9) pull
slip
I consistency index
C (cid:9)
j(cid:9) soil deformation
k (cid:9) modulus of soil deformation
k (cid:9) soil constant due to cohesion component
k' (cid:9) sinkage modulus
k (cid:9) soil constant due to frictional component
k' (cid:9) sinkage modulus
Ix