목차

CHAPTER 1. INTRODUCTION..........................................................................1
1.1 Background..................................................................................................1
1.2 Objectives and methodology of dissertation.................................................3
1.3 Organization of dissertation.........................................................................4
CHAPTER 2. BASIC THEORY AND LITERATURE REVIEW.......................6
2.1 Pre-cutting method.......................................................................................6
2.2 Mechanical pre-cutting................................................................................7
2.3 Rock cutting mechanism by drag-type tool................................................10
2.3.1 Rock cutting theories for chisel picks...............................................10
2.3.2 Rock cutting theories for conical picks.............................................17
2.3.3 Rock cutting by the interaction between drag picks..........................20
2.4 Excavation efficiency of drag-type tool.....................................................24
CHAPTER 3. LINEAR CUTTING TESTS........................................................26
3.1 Introduction................................................................................................26
3.2 Linear cutting machine...............................................................................27
3.2.1 Overview of linear cutting machine..................................................27
3.2.2 Cutting system of linear cutting machine..........................................28
3.2.3 Control system of linear cutting machine..........................................30
3.3 Cutting tool of pre-cutting machine............................................................30
3.3.1 Classification of cutting tools...........................................................30
3.3.2 Description of cutting tool of pre-cutting machine...........................30
3.4 Rock sample...............................................................................................34
3.4.1 Rock-like materials for rock experiments.........................................34
3.4.2 Fabrication of rock samples..............................................................34
3.5 Cutting volume measurement.....................................................................37
3.5.1 Cutting volume measuring method...................................................37
3.5.2 Description of 3D scanner.................................................................38
3.5.3 Measurement of cutting volume by 3D scanning..............................41
3.6 Cutting scheme...........................................................................................43
CHAPTER 4. ANALYSIS OF EFFECT OF TOOL SHAPE.............................44
4.1 Introduction................................................................................................44
4.2 Experimental setup.....................................................................................46
4.3 Relationship between tool shape and rock chip formation..........................48
4.3.1 Cutting force in formation of rock chip.............................................48
4.3.2 Effect of tool shape on rock chip formation......................................50
4.4 Effect of tool shape on cutting force...........................................................52
4.4.1 Effect of clearance angle on cutting force.........................................52
4.4.2 Effect of rake angle on cutting force.................................................59
4.5 Effect of tool shape on normal force...........................................................66
4.5.1 Effect of clearance angle on normal force.........................................66
4.5.2 Effect of rake angle on normal force.................................................72
4.6 Effect of tool shape on cutting volume.......................................................78
4.6.1 Effect of clearance angle on cutting volume.....................................78
4.6.2 Effect of rake angle on cutting volume..............................................82
4.7 Effect of tool shape on specific energy........................................................85
4.7.1 Effect of clearance angle on specific energy.....................................85
4.7.2 Effect of rake angle on specific energy..............................................89
4.8 Summaries.................................................................................................93
CHAPTER 5. ANALYSIS OF CHARACTERISTICS OF MECHANICAL
EXCAVATION............................................................................94
5.1 Introduction................................................................................................94
5.2 Experimental setup.....................................................................................95
5.3 Analysis of characteristics of tool forces by cutting conditions..................97
5.3.1 Effect of penetration depth and spacing on cutting force..................97
5.3.2 Effect of penetration depth and spacing on normal force................101
5.3.3 Analysis of cutting force to normal force ratio................................104
5.3.4 Analysis of peak to mean tool forces ratio.......................................106
5.4 Analysis of characteristics of tool forces by cutting conditions................112
5.4.1 Effect of penetration depth and spacing on cutting volume.............112
5.4.2 Comparison of measured and calculated cutting volume................115
5.5 Analysis of the effect of cutting condition on ridge formation..................121
5.5.1 Effect of penetration depth on ridge formation...............................121
5.5.2 Effect of spacing on ridge formation...............................................122
5.6 Analysis of the effect on specific energy by cutting condition..................128
5.6.1 Effect of penetration depth on specific energy................................128
5.6.2 Effect of spacing on specific energy................................................130
5.7 Summaries...............................................................................................135
CHAPTER 6. ANALYSIS OF RELATIONSHIP BETWEEN EXCAVATION
EFFICIENCY AND ROCK FRAGMENTS.............................136
6.1 Introduction..............................................................................................136
6.2 Rock fragment analysis............................................................................138
6.2.1 Rock cutting tests............................................................................138
6.2.2 Sieve analysis.................................................................................138
6.2.3 Coarseness index............................................................................140
6.3 Comparison between maximum diameter and particle size parameters...141
6.3.1 Correlation between median particle size and coarseness index.....141
6.3.2 Correlation between mean particle size and coarseness index........142
6.3.3 Correlation between absolute particle size and coarseness index....144
6.3.4 Correlation between maximum diameter and coarseness index......145
6.4 Comparison between maximum diameter and coarseness index by cutting
conditions................................................................................................150
6.4.1 Effect of penetration depth..............................................................150
6.4.2 Effect of spacing.............................................................................152
6.4.3 Effect of ratio of spacing to penetration depth................................153
6.5 Comparison of correlation with cutting results.........................................158
6.5.1 Correlation with cutting force.........................................................158
6.5.2 Correlation with normal force.........................................................166
6.5.3 Correlation with cutting volume.....................................................170
6.5.4 Correlation with specific energy.....................................................175
6.6 Summaries...............................................................................................180
CHAPTER 7. CONCLUSIONS AND FUTURE RESEARCH.......................181
7.1 Conclusions..............................................................................................181
7.2 Recommendations for future research......................................................184
REFERENCES...................................................................................................185
APPENDIX A. RESULTS OF LINEAR CUTTING TESTS FOR ANALYSIS OF EFFECT OF TOOL SHAPE..............................................194
APPENDIX B. RESULTS OF LINEAR CUTTING TESTS FOR ANALYSIS OF EXCAVATION CHARACTERISTICS............................219
APPENDIX C. RESULTS OF 3D SCANNING................................................231
APPENDIX D. RESULTS OF ROCK FRAGMENTS ANALYSIS................258
국문요지..............................................................................................................279