EXPERIMENTAL ROCK MECHANICS
PRECISE MEASUREMENTS OF FRACTURE STRENGTH OF ROCKS UNDER UNIFORM COMPRESSIVE STRESS PRESENT SPECIMEN DESIGN EFFECT OF LENGTH/DIAMETER RATIO TO APPARENT STRENGTH AND FRACTURE ANGLE COMPARISON WITH THE CONVENTIONAL METHOD DECREASE OF THE END EFFECTS BY CONFINING PRESSURE REFERENCES CHAPTER DEFORMATION AND FAILURE OF ROCKS UNDER CONFINING PRESSURE DEFORMATION CHARACTERISTICS 2 1 A EXPERIMENTAL PROCEDURE 2 1 B STRESS-STRAIN RELATION 2 1 C MODULUS OF ELASTICITY 2 1 D PERMANENT STRAIN 2 1 E EFFECTS OF PREVIOUS LOADING HYDROSTATIC PRESSURE AXIAL COMPRESSION 2 1 F YIELD STRESS 2 1 G SUMMARY OF THE DEFORMATION CHARACTERISTICS PRESSURE DEPENDENCE OF COMPRESSIVE STRENGTH AND BRITTLE-DUCTILE TRANSITION 2 2 A RELATION BETWEEN STRENGTH AND CONFINING PRESSURE 2 2 B THE COULOMB-MOHR FRACTURE CRITERION 2 2 C BRITTLE-DUCTILE TRANSITION DEFORMATION AND FRACTURE OF ROCKS UNDER THE TRIAXIAL COMPRESSION: THE EFFECT OF THE INTERMEDIATE PRINCIPAL STRESS HISTORY OF COMPRESSION EXPERIMENTS 3 1 A AXIAL LOADING TEST UNDER LATERAL PRESSURE 3 1 B TRUE TRIAXIAL COMPRESSION TEST COMPARISON BETWEEN COMPRESSION AND EXTENSION UNDER CONFINING PRESSURE 3 2 A INTRODUCTION 3 2 B EXPERIMENTAL PROCEDURE CONFINED COMPRESSION TEST CONFINED EXTENSION TEST 3 2 C SPECIMEN MATERIALS 3 2 D EXPERIMENTAL RESULTS EXAMINATIONOFISOTROPYANDHOMOGENEITY BY UNIAXIAL COMPRESSION TESTS COMPARISON OF CONFINED COMPRESSION AND EXTENSION TESTS TRUE TRIAXIAL COMPRESSION EXPERIMENTS 3 3 A INTRODUCTION 3 3 B DESIGN OF THE TRUE TRIAXIAL APPARATUS 3 3 C SPECIMEN DESIGN AND STRAIN MEASUREMENT 3 3 D EXPERIMENTAL PROCEDURE AND ROCKS STUDIED 3 3 E EXPERIMENTAL RESULTS (1) – STRESS-STRAIN CURVES AND FRACTURE STRESSES DUNHAM DOLOMITE SOLNHOFEN LIMESTONE YAMAGUCHI MARBLE MIZUHO TRACHYTE MANAZURU ANDESITE INADA GRANITE ORIKABE MONZONITE SUMMARY 3 3 F EXPERIMENTAL RESULTS (2) –YIELD STRESSES 3 3 G FAILURE CRITERIA OF ROCKS PREVIOUS STUDIES FRACTURE CRITERION YIELD CRITERION 3 3 H DUCTILITY, FRACTURE PATTERN AND DILATANCY DUCTILITY AND STRESS DROP FRACTURE PATTERN DILATANCY 3 3 I FRACTURE OF AN INHOMOGENEOUS ROCK AND AN ANISOTROPIC ROCK INHOMOGENEOUS ROCK ANISOTROPIC ROCK 3 3 J OTHER RECENT EXPERIMENTS 3 3 K FUTURE PROBLEMS APPENDIX PART II ACOUSTIC EMISSION (AE) CHAPTER AE ACTIVITY INTRODUCTION AE ACTIVITY UNDER SOME SIMPLE LOADINGS THREE PATTERNS OF AE ACTIVITY SOURCE LOCATION OF AE EXPERIMENTAL PROCEDURE 5 2 A MEASUREMENT OF VERY HIGH FREQUENCY ELASTIC WAVES 5 2 B DETERMINATION OF SOURCE LOCATION OF AE EVENTS ONE-DIMENSIONAL CASE TWO-DIMENSIONAL CASE EXPERIMENTAL RESULTS 5 3 A GRANITE (HETEROGENEOUS SILICATE ROCK) 5 3 B ANDESITE (MODERATELY HETEROGENEOUS SILICATE ROCK) 5 3 C MIZUHO TRACHYTE (NEARLY HOMOGENEOUS SILICATE ROCK) 5 3 D YAMAGUCHI MARBLE WITH DIFFERENT GRAIN SIZES 5 3 E FRACTURE OF A SEMI-INFINITE BODY BY AN INNER PRESSURE SOURCE MAGNITUDE–FREQUENCY RELATION OF AE EVENTS EXPERIMENTAL PROCEDURE AND SPECIMEN MATERIALS THE M VALUE IN THE ISHIMOTO-IIDA EQUATION TYPES OF THE MAGNITUDE–FREQUENCY RELATIONS AND THE STRUCTURE OF THE MEDIUM EFFECTS OF MEASUREMENTS BY DIFFERENT FREQUENCIES AND DIFFERENT DYNAMIC RANGES OF ACOUSTIC WAVES AE ACTIVITY UNDER CYCLIC LOADING EFFECT OF TIDAL LOADING 7 1 A INTRODUCTION 7 1 B OBSERVATIONS OF AE EVENTS DIRECTLY ABOVE THE FOCAL REGION OF THE 1980 EARTHQUAKE SWARM 7 1 C SEISMIC ACTIVITY AND OCEAN TIDE AE UNDER CYCLIC COMPRESSION 7 2 A EXPERIMENTAL PROCEDURE 7 2 B AE EVENTS UNDER CYCLIC COMPRESSION AE UNDER CYCLIC BENDING 7 3 A INTRODUCTION 7 3 B EXPERIMENT A 7 3 C EXPERIMENT B 7 3 D CONCLUDING REMARKS PART III ROCK FRICTION AND EARTHQUAKES CHAPTER LABORATORY EXPERIMENT OF ROCK FRICTION NEW DESIGN OF A DOUBLE-SHEAR TYPE APPARATUS EXPERIMENTAL RESULT TYPICAL STICK-SLIP EVENTS IN NATURE AND EARTHQUAKES USU VOLCANO AND UNZEN VOLCANO, JAPAN SANRIKU-OKI AND TOKAI-NANKAI REGIONS, JAPAN STICK-SLIP AND FRACTURE AS AN EARTHQUAKE MECHANISM CHAPTER 10 SOME FEATURES IN THE OCCURRENCE OF RECENT LARGE EARTHQUAKES 10 1 GLOBAL PATTERN OF SEISMIC ACTIVITY 10 2 ACTIVE AND QUIET PERIODS IN THE MAIN SEISMIC ZONES 10 2 A ALASKA – ALEUTIAN – KAMCHATKA – N JAPAN 10 2 B ALPS – HIMALAYA – SUNDA 10 3 SOME PRECURSORY SEISMIC ACTIVITY OF RECENT LARGE SHALLOW EARTHQUAKES 10 3 A INTRODUCTION 10 3 B 2001 BHUJ (INDIA) EARTHQUAKE 10 3 C 2003 TOKACHI-OKI (JAPAN) EARTHQUAKE