Page 11 - Engineering Rock Mass Classification_ Tunnelling, Foundations and Landslides

x Contents

Tensile Strength Across Discontinuous Joints 180
Dynamic Strength of Rock Mass 181
Residual Strength Parameters 181

14. Rock Mass Quality for Open Tunnel Boring Machines 185

Introduction 185
Q and QTBM 186
Penetration and Advance Rates 188
Cutter Wear 189
Penetration and Advance Rates versus QTBM 189
Estimating Time for Completion 190
Risk Management 190

15. Strength of Discontinuities 193

Introduction 193
Joint Wall Roughness Coefficient 193
Joint Wall Compressive Strength 196
Joint Matching Coefficient 198
Residual Angle of Friction 198
Shear Strength of Joints 200
Dynamic Shear Strength of Rough Rock Joints 201
Theory of Shear Strength at Very High Confining
Stress 202
Normal and Shear Stiffness of Rock Joints 203

16. Shear Strength of Rock Masses in Slopes 205

Mohr-Coulomb Strength Parameters 205
Non-Linear Failure Envelopes for Rock Masses 205
Strength of Rock Masses in Slopes 209
Back Analysis of Distressed Slopes 210

17. Types of Failures of Rock and Soil Slopes 211

Introduction 211
Planar (Translational) Failure 211
3D Wedge Failure 211
Circular (Rotational) Failure 211
Toppling Failure (Topples) 213
Ravelling Slopes (Falls) 214
Effect of Slope Height and Groundwater Conditions on Safe
214
Slope Angle 216
A Basic Landslide Classification System 217
Causative Classification 217
Comprehensive Classification System of Landslides 217
Landslide in Over-Consolidated Clays 224
Rock Slope Failures 229
Landslide Dams