Rock Mass Classification: A Practical Approach in Civil Engineering [1 ed.] 0080430139, 9780080430133

Table of contents :
Front Cover......Page 1
ROCK MASS CLASSIFICATION: A Practical Approach in Civil Engineering......Page 4
Copyright Page......Page 5
CONTENTS......Page 9
PREFACE......Page 7
1.1 The Classification......Page 16
1.3 Management of Uncertainties......Page 17
1.4 Present Day Practice......Page 18
1.5 Scope of the Book......Page 19
2.2 Treatment for Tunnels......Page 20
2.3 Treatment for Dam Foundations......Page 22
3.2 Homogeneity and Inhomogeneity......Page 25
3.4 Class l and II Rocks......Page 27
3.5 Uniaxial Compression......Page 28
3.7 Classification on the Basis of Slake Durability Index......Page 30
4.2 Direct Method......Page 32
4.3 Indirect Methods......Page 33
4.4 Weighted Joint Density......Page 35
5.3 Rock Load Factor......Page 40
5.4 Modified Terzaghi's Theory for Tunnels and Caverns......Page 46
6.2 Collection of Field Data......Page 49
6.3 Estimation of Rock Mass Rating (RMR)......Page 53
6.4 Applications of RMR......Page 54
6.6 Precautions......Page 59
7.1 Introduction......Page 62
7.2 The Tunnelling Conditions......Page 63
7.3 Empirical Approach......Page 65
7.4 Theoretical / Analytical Approach......Page 74
7.5 Effect of Thickness of Weak Band on Squeezing Ground Condition......Page 75
8.1 The Q-System......Page 77
8.3 Updating of the Q-system......Page 84
8.4 Collection of Field Data......Page 85
8.6 Estimation of Support Pressure......Page 87
8.7 Unsupported Span......Page 95
8.8 Design of Supports......Page 96
8.9 New Austrian Tunnelling Method (NATM)......Page 99
8.10 Norwegian Method of Tunnelling (NMT)......Page 101
8.11 Other Applications of the Q - System......Page 102
9.1 Introduction......Page 107
9.2 Inter-relation Between Q and RMR......Page 108
9.4 Prediction of Support Pressure......Page 111
9.5 Effect of Tunnel Size on Support Pressure......Page 114
9.6 Correlations for Estimating Tunnel Closure......Page 116
9.7 Effect of Tunnel Depth on Support Pressure and Closure in Tunnels......Page 117
9.8 Approach for Obtaining Ground Reaction Curve (GRC)......Page 118
9.9 Coefficient of Volumetric Expansion of Failed Rock Mass......Page 120
10.2 Selection of Parameters used in RMi......Page 123
10.3 Calibration of RMi from Known Rock Mass Strength Data......Page 124
10.4 Scale Effect......Page 126
10.5 Examples (Palmstrom, 1995)......Page 130
10.6 Applications of RMi......Page 131
10.8 Limitations of RMi......Page 132
11.1 Introduction......Page 135
11.3 Classification of Management Conditions for Rate of Tunnelling......Page 136
11.4 Combined Effect of Ground and Management Conditions on Rate of Tunnelling......Page 141
12.1 Support Pressure......Page 143
12.2 Wall Support in Caverns......Page 144
12.3 Roof Support in Caverns......Page 146
12.6 Rock Reinforcement Near Intersections......Page 148
12.8 Precautions......Page 149
13.2 Effect of Intermediate Principal Stress on Tangential Stress at Failure in Tunnels......Page 151
13.3 Uniaxial Compressive Strength of Rock Mass......Page 154
13.4 Reason for Strength Enhancement in Tunnels and A Suggested New Failure Theory......Page 156
13.6 Tensile Strength Across Discontinuous Joints......Page 158
13.7 Dynamic Strength of Rock Mass......Page 159
13.8 Residual Strength Parameters......Page 161
14.2 Joint Wall Roughness Coefficient (JRC)......Page 163
14.3 Joint Wall Compressive Strength (JCS)......Page 165
14.5 Angle of Internal Friction......Page 169
14.6 Shear Strength of Joints......Page 170
15.2 Non-Linear Failure Envelopes for Rock Masses......Page 173
15.4 Back Analysis of Distressed Slopes......Page 177
16.4 Circular (Rotational) Failure......Page 179
16.5 Toppling Failure (Topples)......Page 181
16.6 Ravelling Slopes (Falls)......Page 182
16.8 Landslide Classification System......Page 184
17.1 The Slope Mass Rating (SMR)......Page 186
17.3 Support Measures......Page 190
17.4 Modified SMR Approach......Page 191
17.5 Case Study of Stability Analysis Using Modified SMR Approach......Page 193
18.1 Introduction......Page 199
18.2 Landslide Hazard Zonation Maps - The Methodology......Page 200
18.3 A Case History......Page 205
18.4 Proposition for Tea Gardens......Page 214
19.2 Classification for Net Safe Bearing Pressure......Page 215
19.3 Allowable Bearing Pressure......Page 216
19.4 Coefficient of Elastic Uniform Compression for Machine Foundations......Page 220
20.2 Assessing the Rippability......Page 222
20.3 Rock Mass Classification According to Ease of Ripping......Page 223
20.4 Empirical Methods in Blasting......Page 225
21.1 Drillability and Affecting Parameters......Page 228
21.2 Classification for Drilling Condition......Page 230
21.3 Other Approaches......Page 232
22.2 Permeability of Various Rock Types......Page 234
22.3 Permeability for Classifying Rock Masses......Page 235
22.5 Determination of Permeability......Page 236
22.6 Grouting......Page 237
23.1 Gouge......Page 245
23.2 Influence of Gouge Material......Page 246
23.3 Shear Strength of Filled Discontinuities (Silty to Clayey Gouge)......Page 249
23.4 Dynamic Strength......Page 250
24.3 Uniaxial Compressive Strength (UCS)......Page 252
24.5 Strength Criterion......Page 253
24.7 Half-Tunnels......Page 254
25.1 Geological Strength Index (GSI)......Page 257
25.2 Modified Strength Criterion......Page 258
25.3 Mohr-Coulomb Strength Parameters......Page 260
25.5 Selection of Rock Parameters for Intact Schistose......Page 262
26.2 Critical Parameters......Page 265
26.3 Parameter Intensity and Dominance......Page 266
26.4 Classification of Rock Mass......Page 268
26.5 Example for Studying Parameter Dominance in Underground Excavation for a Coal Mine with Flat Roof......Page 269
26.7 Application in Entropy Management......Page 271
27.2 Classification of Geological Conditions and Stress Regimes......Page 273
27.3 Variation of Insitu Stresses with Depth......Page 275
Author Index......Page 278
Subject Index......Page 280