TUNNELLING IN WEAK ROCKS
CONTENTS INTRODUCTION REFERENCES APPLICATION OF GEOPHYSICS IN TUNNELLING AND SITE SURVEY ACTIVITIES 21 GEOPHYSICAL EXPLORATION 22 EXAMPLES OF APPLICATION 23 PREDICTION AHEAD OF TUNNEL FACE WITH SOURCE PLACED ON FACE 24 APPLICATION TO CONSTRUCTION SITE TERZAGHI’S ROCK LOAD THEORY 31 INTRODUCTION 32 ROCK CLASSES 33 ROCK LOAD FACTOR 34 MODI?ED TERZAGHI’S THEORY FOR TUNNELS AND CAVERNS ROCK MASS RATING (RMR) 41 INTRODUCTION 42 COLLECTION OF ?ELD DATA 43 ESTIMATION OF ROCK MASS RATING 44 APPLICATIONS OF RMR 45 PRECAUTIONS 46 TUNNEL ALIGNMENT ROCK MASS QUALITY Q 51 THE Q-SYSTEM 52 THE JOINT ORIENTATION AND THE Q-SYSTEM 53 UPDATING THE Q-SYSTEM 54 COLLECTION OF ?ELD DATA 55 CLASSI?CATION OF THE ROCK MASS 56 ESTIMATION OF SUPPORT PRESSURE 57 UNSUPPORTED SPAN 58 ROCK MASS CHARACTERIZATION 59 CONCLUDING REMARKS ROCK MASS NUMBER 61 INTRODUCTION 62 INTERRELATION BETWEEN Q AND RMR 63 PREDICTION OF GROUND CONDITIONS 64 PREDICTION OF SUPPORT PRESSURE 65 EFFECT OF TUNNEL SIZE ON SUPPORT PRESSURE 66 CORRELATIONS FOR ESTIMATING TUNNEL CLOSURE 67 EFFECT OF TUNNEL DEPTH ON SUPPORT PRESSURE AND CLOSURE IN TUNNELS 68 APPROACH FOR OBTAINING GROUND REACTION CURVE (GRC) STRENGTH OF DISCONTINUITIES 71 INTRODUCTION 72 JOINT WALL ROUGHNESS COEF?CIENT (JRC) 73 JOINT WALL COMPRESSIVE STRENGTH (JCS) 74 JOINT MATCHING COEF?CIENT (JMC) 75 RESIDUAL ANGLE OF FRICTION 76 SHEAR STRENGTH OF JOINTS 77 DYNAMIC SHEAR STRENGTH OF ROUGH ROCK JOINTS 78 THEORY OF SHEAR STRENGTH AT VERY HIGH CON?NING STRESS 79 NORMAL AND SHEAR STIFFNESS OF ROCK JOINTS STRENGTH ENHANCEMENT OF ROCK MASS IN TUNNELS 81 CAUSES OF STRENGTH ENHANCEMENT 82 EFFECT OF INTERMEDIATE PRINCIPAL STRESS ON TANGENTIAL STRESS AT FAILURE IN TUNNELS 83 UNIAXIAL COMPRESSIVE STRENGTH OF ROCK MASS 84 REASON FOR STRENGTH ENHANCEMENT IN TUNNELS AND A NEW FAILURE THEORY 85 CRITICAL STRAIN OF ROCK MASS 86 CRITERION FOR SQUEEZING/ROCK BURST OF ROCK MASSES 87 TENSILE STRENGTH ACROSS DISCONTINUOUS JOINTS 88 DYNAMIC STRENGTH OF ROCK MASS 89 RESIDUAL STRENGTH PARAMETERS THE NEW AUSTRIAN TUNNELLING METHOD 91 OLD TUNNELLING PRACTICE 92 DEVELOPMENT OF CONSTRUCTION AND LINING METHODS 93 MODERN TUNNELLING METHODS 94 TEMPORARY SUPPORTS 95 PHILOSOPHY OF NATM 96 FINAL DIMENSIONING BY MEASUREMENT 97 CONCLUDING REMARKS NORWEGIAN METHOD OF TUNNELLING 101 INTRODUCTION 102 UNSUPPORTED SPAN 103 DESIGN OF SUPPORTS 104 DESIGN OF STEEL ?BER REINFORCED SHOTCRETE 105 DRAINAGE MEASURES 106 EXPERIENCES IN POOR ROCK CONDITIONS 107 CONCLUDING REMARKS BLASTING FOR TUNNELS AND ROADWAYS 111 INTRODUCTION 112 BLASTING MECHANICS 113 BLAST HOLES NOMENCLATURE 114 TYPES OF CUT 115 TUNNEL BLAST PERFORMANCE 116 PARAMETERS IN?UENCING TUNNEL BLAST RESULTS 117 MODELS FOR PREDICTION OF TUNNEL BLAST RESULTS 118 BLAST DESIGN ROCK BOLTING 121 GENERAL 122 TYPES OF ROCK BOLTS 123 SELECTION OF ROCK BOLTS 124 INSTALLATION OF ROCK BOLTS 125 PULL-OUT TESTS 126 REINFORCEMENT OF JOINTED ROCK MASS AROUND OPENINGS 127 BOLTING PATTERN 128 FLOOR BOLTING TUNNELLING HAZARDS 131 INTRODUCTION 132 THE TUNNELLING HAZARDS 133 EMPIRICAL APPROACH FOR PREDICTING DEGREE OF SQUEEZING 134 SUDDEN ?OODING OF TUNNELS 135 CHIMNEY FORMATION 136 ENVIRONMENTAL HAZARDS DUE TO TOXIC OR EXPLOSIVE GASES AND GEOTHERMAL GRADIENT 137 INTERACTION BETWEEN ROCK PARAMETERS 138 CONCLUDING REMARKS TUNNEL INSTRUMENTATION 141 INTRODUCTION 142 BASIC CONSIDERATIONS AND REQUIREMENTS FOR THE DESIGN OF AN OPENING IN ROCK 143 DATA REQUIREMENT 144 INSTRUMENTATION FOR TUNNELLING 145 STRESS ?ELD 146 SUPPORT PRESSURE IN TUNNELS 147 MEASUREMENT OF ROCK MASS BEHAVIOR AROUND AN UNDERGROUND OPENING BY BOREHOLE EXTENSOMETER 148 CASE HISTORIES 149 LAYOUT OF A TYPICAL TEST SECTION TUNNELLING MACHINES 151 GENERAL 152 SYSTEM’S MIS-MATCH 153 TUNNEL JUMBO 154 MUCK HAULING EQUIPMENT 155 TUNNEL BORING MACHINE (TBM) 156 SAFETY DURING TUNNELLING ROCK MASS QUALITY FOR TUNNEL BORING MACHINES (QTBM) 161 INTRODUCTION 162 Q AND QTBM 163 PENETRATION AND ADVANCE RATES 164 CUTTER WEAR 165 PENETRATION AND ADVANCE RATE VS QTBM 166 ESTIMATING TIME FOR COMPLETION METRO TUNNELS 171 INTRODUCTION 172 SHIELDED TUNNEL BORING MACHINES 173 PRECAST LINING 174 BUILDING CONDITION SURVEY AND VIBRATION LIMIT 175 IMPACT ON THE STRUCTURES 176 SUBSIDENCE 177 PORTAL AND CUT SLOPES TUNNELLING IN SWELLING ROCKS 181 INTRODUCTION 182 SUPPORT PRESSURES IN SWELLING GROUND 183 VARIATION OF SUPPORT PRESSURE WITH TIME 184 CASE HISTORIES 185 DESIGN APPROACH TUNNELLING THROUGH SQUEEZING GROUND CONDITION 191 INTRODUCTION 192 CRITERION FOR SQUEEZING GROUND CONDITION 193 ELASTO-PLASTIC THEORY OF SQUEEZING GROUND 194 DISPLACEMENTS OF TUNNEL WALLS 195 COMPACTION ZONE WITHIN BROKEN ZONE 196 FACE ADVANCE FOR STABILIZATION OF BROKEN ZONE 197 GROUND RESPONSE CURVE 198 STRAIN CRITERION OF SQUEEZING GROUND CONDITION 199 SUPPORT DESIGN CASE HISTORY OF TUNNEL IN SQUEEZING GROUND 201 INTRODUCTION 202 REGIONAL GEOLOGY, TUNNELLING PROBLEMS AND ALTERNATIVE LAYOUTS 203 TECTONIC ACTIVITY AND TUNNEL LINING 204 TUNNEL CONSTRUCTION AND INSTRUMENTATION IN THE INTRA-THRUST ZONE AT KALAWAR 205 TUNNEL CONSTRUCTION AND INSTRUMENTATION IN INTRA-THRUST ZONE AT CHHIBRO 206 ELASTO-PLASTIC THEORY 207 CONCLUSIONS TUNNELS IN SEISMIC AREAS 211 INTRODUCTION 212 RESPONSE OF AN UNDERGROUND STRUCTURE TO DYNAMIC LOADING 213 OBSERVED RESPONSE 214 CASE HISTORY OF 1991 UTTARKASHI EARTHQUAKE 215 PSEUDO-STATIC THEORY OF SEISMIC SUPPORT PRESSURE 216 SUPPORT SYSTEM FOR BLAST LOADING ROCK BURST IN TUNNELS 221 INTRODUCTION 222 CONDITIONS FOR ROCK BURST IN DEEP TUNNELS 223 CONCEPT OF STRAIN ENERGY RELEASE RATE 224 SEISMIC ENERGY RELEASED IN A ROCK BURST 225 SEMI-EMPIRICAL CRITERION OF PREDICTING ROCK BURST 226 SUGGESTION FOR REDUCING SEVERITY OF ROCK BURSTS PRESSURE TUNNELS 231 INTRODUCTION 232 MINIMUM OVERBURDEN ABOVE A PRESSURE TUNNEL 233 SOLID CONCRETE LINING 234 CRACKED PLAIN CEMENT CONCRETE LINING 235 STEEL LINER IN PENSTOCK 236 HYDRAULIC FRACTURING NEAR JUNCTION OF PRESSURE TUNNEL AND PENSTOCK SHAFTS 241 INTRODUCTION 242 SHAPES OF SHAFT 243 SELF-SUPPORTING SHAFT 244 SUPPORT PRESSURES ON THE WALL OF SHAFT 245 DESIGN OF SUPPORT SYSTEM 246 SURGE SHAFT EXCAVATION SELF-COMPACTING CONCRETE HALF TUNNELS APPLICATION OF ROCK MASS CLASSI?CATION WEDGE ANALYSIS STRESS DISTRIBUTION AROUND HALF TUNNEL CONTRACTUAL RISK SHARING THE RISK MANAGEMENT OF RISK CONSTRUCTION PLANNING AND RISK TIME AND COST ESTIMATES RATE OF TUNNELLING CLASSI?CATION OF GROUND/JOB CONDITIONS FOR RATE OF TUNNELLING CLASSI?CATION OF MANAGEMENT CONDITIONS FOR RATE OF TUNNELLING COMBINED EFFECT OF GROUND AND MANAGEMENT CONDITIONS ON RATE OF TUNNELLING TUNNEL MANAGEMENT POOR TENDER SPECI?CATIONS CONTRACTING PRACTICE QUALITY MANAGEMENT BY INTERNATIONAL TUNNELLING ASSOCIATION INTEGRATED METHOD OF TUNNELLING PROBE HOLES EFFECT OF SEISMICITY SELECTION OF TYPE OF SUPPORT SYSTEM STEEL ?BER REINFORCED SHOTCRETE TREATMENT OF SHEAR ZONE SHOTCRETE ROCK/ROOF BOLTS 2810 STEEL RIBS 2811 GROUTING IN PRESSURE TUNNELS 2812 DESIGN OF INTEGRATED SUPPORT SYSTEM 2813 SPECIAL REQUIREMENTS CRITICAL STATE ROCK MECHANICS AND ITS APPLICATIONS GENERAL SUGGESTED MODEL FOR ROCK MASS RESIDUAL STRENGTH EFFECT OF CON?NING PRESSURE ON FRICTION ANGLE