GEOTECHNICAL CHARACTERIZATION OF LUNAR REGOLITH SIMULANTS By CHUNMEI HE Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Dissertation Advisor: Dr. Xiangwu Zeng Department of Civil Engineering Case Western Reserve University May, 2010 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of _____________________________________________________ candidate for the ______________________degree *. (signed)_______________________________________________ (chair of the committee) ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ (date) _______________________ *We also certify that written approval has been obtained for any proprietary material contained therein. TABLE OF CONTENTS LIST OF TABLES .............................................................................................................. v LIST OF FIGURES .......................................................................................................... vii ACKNOWLEDGEMENT ................................................................................................. xi ABSTRACT ...................................................................................................................... xii CHAPTER 1 INTRODUCTION ........................................................................................ 1 1.1 Past Lunar Exploration ......................................................................................... 1 1.2 Future Lunar Exploration ..................................................................................... 8 1.2.1 Why the Moon?............................................................................................. 9 1.3 Motivation for the Research ............................................................................... 12 1.4 Scope of Work .................................................................................................... 14 1.5 Outline of the Disseatation ................................................................................. 16 CHAPTER 2 LITERATURE REVIEW ........................................................................... 18 2.1 Lunar Environment ............................................................................................ 18 2.2 Lunar Regolith .................................................................................................... 24 2.2.1 Formation of the Lunar Regolith ................................................................ 25 2.2.2 Lunar Samples ............................................................................................ 27 2.3 Geotechnical Properties of Lunar Regolith ........................................................ 34 i 2.3.1 Particle Size Distribution ............................................................................ 36 2.3.2 Particle Shapes ............................................................................................ 42 2.3.3 Specific Gravity .......................................................................................... 44 2.3.4 Bulk Density and Porosity .......................................................................... 52 2.3.5 Relative Density .......................................................................................... 61 2.3.6 Shear Strength ............................................................................................. 66 2.3.7 Compressibility ........................................................................................... 75 2.4 Review of Lunar Regolith Simulants ................................................................. 80 2.4.1 MLS-1 ......................................................................................................... 81 2.4.2 JSC-1 ........................................................................................................... 85 2.4.3 GRC-1 ......................................................................................................... 90 2.4.4 Other Lunar Regolith Simulants ................................................................. 93 CHAPTER 3 GEOTECHNICAL PROPERTIES OF JSC-1A ......................................... 95 3.1 Method for Creating JSC-1A ............................................................................. 95 3.2 Geotechnical Properties of JSC-1A .................................................................... 98 3.2.1 Particle Size Distribution ............................................................................ 99 3.2.2 Specific Gravity ........................................................................................ 109 3.2.3 Maximum and Minimum Densities .......................................................... 113 3.2.4 Porosity and Void Ratio ............................................................................ 116 3.2.5 Compaction Test ....................................................................................... 117 ii 3.2.6 Shear Strength ........................................................................................... 120 3.2.7 Compressibility ......................................................................................... 130 3.3 Conclusions of JSC-1A Lunar Mare Regoligh Simulant ................................. 136 3.4 Particle Size Distribution of JSC-1AF Dust Simulant ..................................... 140 CHAPTER 4 GEOTECHNICAL PROPERTIES OF NU-LHT-2M .............................. 143 4.1 Method for Creating NU-LHT-2M .................................................................. 144 4.2 Geotechnical Properties of NU-LHT-2M ........................................................ 148 4.2.1 Particle Size Distribution .......................................................................... 148 4.2.2 Specific Gravity ........................................................................................ 153 4.2.3 Maximum and Minimum Densities .......................................................... 154 4.2.4 Porosity and Void Ratio ............................................................................ 155 4.2.5 Compaction Test ....................................................................................... 156 4.2.6 Shear Strength ........................................................................................... 157 4.2.7 Compressibility ......................................................................................... 160 4.3 Conclusions ...................................................................................................... 162 CHAPTER 5 GEOTECHNICAL PROPERTIES OF GRC-3 ........................................ 164 5.1 Method for Creating GRC-3 ............................................................................ 164 5.2 Geotechnical Properties of GRC-3 ................................................................... 169 5.2.1 Particle Size Distribution .......................................................................... 169 5.2.2 Atterberg Limits ........................................................................................ 172 iii 5.2.3 Specific Gravity ........................................................................................ 177 5.2.4 Maximum and Minimum Densities .......................................................... 178 5.2.5 Porosity and Void Ratio ............................................................................ 179 5.2.6 Compaction Test ....................................................................................... 180 5.2.7 Shear Strength ........................................................................................... 181 5.2.8 Compressibility ......................................................................................... 184 5.2.9 Stiffness and Poisson’s Ratio .................................................................... 186 5.3 Conclusions ...................................................................................................... 198 CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS ................................... 200 6.1 Introduction ...................................................................................................... 200 6.2 Conclusions ...................................................................................................... 201 6.2.1 Geotechnical Properties of JSC-1A .......................................................... 201 6.2.2 Particle Size Distribution of JSC-1A ........................................................ 202 6.2.3 Geotechnical Properties of NU-LHT-2M ................................................. 203 6.2.4 Geotechnical Properties of GRC-3 ........................................................... 204 6.3 Suggestions for Future Study ........................................................................... 206 REFERENCES ............................................................................................................... 208 iv LIST OF TABLES Table 1.1 Lunar exploration timeline .................................................................................. 5 Table 1.2 NASA lunar exploration themes ....................................................................... 10 Table 1.3 Subcategorized objectives for lunar exploration .............................................