Guidelines for Open Pit Slope Design is a comprehensive account of the open pit slope design process. Created as an outcome of the Large Open Pit (LOP) project, an international research and technology transfer project on the stability of rock slopes in open pit mines, this book provides an up-to-date compendium of knowledge of the slope design processes that should be followed and the tools that are available to aid slope design practitioners.
This book links innovative mining geomechanics research into the strength of closely jointed rock masses with the most recent advances in numerical modelling, creating more effective ways for predicting the reliability of rock slopes in open pit mines. It sets out the key elements of slope design, the required levels of effort and the acceptance criteria that are needed to satisfy best practice with respect to pit slope investigation, design, implementation and performance monitoring.
This book will assist open pit mine slope design practitioners, including engineering geologists, geotechnical engineers, mining engineers and civil engineers and mine managers, in meeting stakeholder requirements for pit slopes that are stable, in regards to safety, ore recovery and financial return, for the required life of the mine.
Author(s): John Read, Peter Stacey
Edition: 1
Publisher: CRC Press
Year: 2009
Language: English
Pages: 510
Tags: Горно-геологическая отрасль;Горное дело;Открытые горные работы;
cover
......Page 1
Contents
......Page 6
Preface and acknowledgments......Page 14
1.2 Pit slope designs......Page 16
1.2.2 Economic factors......Page 17
1.2.3 Environmental and regulatory factors......Page 18
1.3.2 Instability......Page 19
1.4.2 Geotechnical model......Page 21
1.4.4 Acceptance criteria (Chapter 9)......Page 23
1.4.5 Slope design methods (Chapter 10)......Page 24
1.4.7 Slope evaluation and monitoring (Chapter 12)......Page 25
1.5.1 Project development......Page 26
1.6.1 Overview......Page 27
1.7 Conclusion......Page 29
2.2.1 Introduction......Page 30
2.2.2 General geotechnical logging......Page 32
2.2.3 Mapping for structural analyses......Page 34
2.2.4 Surface geophysical techniques......Page 37
2.3.1 Classification......Page 38
2.4.2 Planning and scoping......Page 41
2.4.5 Downhole surveying......Page 42
2.4.6 Core orientation......Page 43
2.4.7 Core handling and documentation......Page 44
2.4.8 Core sampling, storage and preservation......Page 46
2.4.9 Core logging......Page 47
2.4.10 Downhole geophysical techniques......Page 54
2.5.1 Approach to groundwater data collection......Page 55
2.5.2 Tests conducted during RC drilling......Page 57
2.5.3 Piezometer installation......Page 59
2.5.4 Guidance notes: installation of test wells for pit slope depressurisation......Page 62
2.5.5 Hydraulic tests......Page 64
2.5.6 Setting up pilot depressurisation trials......Page 66
Endnotes......Page 67
3.2 Physical setting......Page 68
3.3.2 Porphyry deposits......Page 70
3.3.4 Kimberlites......Page 71
3.3.7 Stratabound deposits......Page 72
3.4 Geotechnical requirements......Page 74
3.5.1 Distribution of earthquakes......Page 77
3.5.2 Seismic risk data......Page 80
3.6 Regional stress......Page 81
4.2.1 Major structures......Page 84
4.2.2 Fabric......Page 90
4.3.3 Sedimentary......Page 91
4.4.2 Stereographic projection......Page 92
4.4.3 Discrete fracture network modelling......Page 94
4.5.2 Example application......Page 95
5.2.1 Introduction......Page 98
5.2.2 Index properties......Page 100
5.2.3 Mechanical properties......Page 103
5.2.4 Special conditions......Page 107
5.3.2 Defect strength......Page 109
5.4.2 RMR, Bieniawski......Page 132
5.4.3 Laubscher IRMR and MRMR......Page 134
5.4.4 Hoek-Brown GSI......Page 138
5.5.2 Laubscher strength criteria......Page 142
5.5.3 Hoek-Brown strength criterion......Page 143
5.5.4 CNI criterion......Page 145
5.5.5 Directional rock mass strength......Page 147
5.5.6 Synthetic rock mass model......Page 153
6.1.2 Porosity and pore pressure......Page 156
6.1.3 General mine dewatering and localised pore pressure control......Page 161
6.1.4 Making the decision to depressurise......Page 163
6.2.1 Groundwater flow......Page 166
6.2.2 Porous-medium (intergranular) groundwater settings......Page 169
6.2.3 Fracture-flow groundwater settings......Page 171
6.2.4 Influences on fracturing and groundwater......Page 176
6.2.5 Mechanisms controlling pore pressure reduction......Page 178
6.3.2 Conceptual mine scale hydrogeological model......Page 181
6.3.3 Detailed hydrogeological model of pit slopes......Page 182
6.4.1 Introduction......Page 183
6.4.2 Numerical hydrogeological models for mine scale dewatering applications......Page 184
6.4.3 Pit slope scale numerical modelling......Page 188
6.4.4 Numerical modelling for pit slope pore pressures......Page 190
6.4.5 Coupling pore pressure and geotechnical models......Page 194
6.5.1 General mine dewatering......Page 195
6.5.2 Specific programs for control of pit slope pressures......Page 196
6.5.5 Water management and control......Page 207
6.6.2 Relative pore pressure behaviour between high-order and low-order fractures......Page 210
6.6.3 Standardising the interaction between pore pressure and geotechnical models......Page 211
6.6.5 Coupled pore pressure and geotechnical modelling......Page 212
7.2.1 Required output......Page 216
7.2.3 Building the model......Page 217
7.2.4 Block modelling approach......Page 220
7.3.1 Scale effects......Page 221
7.3.3 Hoek-Brown rock mass strength criterion......Page 225
7.3.4 Pore pressure considerations......Page 226
8.3 Impact of data uncertainty......Page 228
8.4.2 Subjective assessment......Page 230
8.5.1 Geotechnical reporting system......Page 231
8.6 Summary and conclusions......Page 234
9.2.1 FoS as a design criterion......Page 236
9.3.1 PoF as a design criterion......Page 238
9.3.2 Acceptable levels of PoF......Page 239
9.4.1 Introduction......Page 240
9.4.2 Cost–benefit analysis......Page 241
9.4.3 Risk model process......Page 243
9.4.4 Formulating acceptance criteria......Page 247
9.4.5 Slope angles and levels of confidence......Page 249
9.5 Summary......Page 250
10.1.1 Design steps......Page 252
10.1.2 Design analyses......Page 253
10.2.1 Benches......Page 254
10.2.2 Inter-ramp slopes......Page 259
10.3.2 Empirical methods......Page 261
10.3.3 Limit equilibrium methods......Page 263
10.3.4 Numerical methods......Page 268
10.3.5 Summary recommendations......Page 278
11.2.2 Open pit design philosophy......Page 280
11.2.3 Open pit design process......Page 282
11.2.4 Application of slope design criteria in mine design......Page 283
11.3.1 Introduction......Page 291
11.3.2 Design terminology......Page 292
11.3.3 Blast damage mechanisms......Page 293
11.3.4 Influence of geology on blast-induced damage......Page 294
11.3.5 Controlled blasting techniques......Page 297
11.3.6 Delay configuration......Page 307
11.3.7 Design implementation......Page 309
11.3.8 Performance monitoring and analysis......Page 311
11.3.9 Design refinement......Page 314
11.3.10 Design platform......Page 320
11.3.11 Planning and optimisation cycle......Page 321
11.4.1 Excavation......Page 325
11.4.2 Scaling and bench cleanup......Page 327
11.5.1 Basic approaches......Page 328
11.5.2 Stabilisation, repair and support methods......Page 329
11.5.3 Design considerations......Page 330
11.5.4 Economic considerations......Page 331
11.5.6 Specific situations......Page 332
11.5.7 Reinforcement measures......Page 333
11.5.8 Rockfall protection measures......Page 340
12.1.2 Geotechnical model validation and refinement......Page 342
12.1.3 Bench performance......Page 344
12.1.4 Inter-ramp slope performance......Page 352
12.1.5 Overall slope performance......Page 354
12.2.1 Introduction......Page 357
12.2.2 Movement monitoring systems......Page 358
12.2.3 Guidelines on the execution of monitoring programs......Page 378
12.3.1 Introduction......Page 385
12.3.2 Hazard management plan......Page 386
13.1.2 Purpose and content of this chapter......Page 396
13.1.3 Sources of information......Page 397
13.2.2 General risk management process......Page 398
13.2.3 Risk management in the minerals industry......Page 399
13.3 Geotechnical risk management for open pit slopes......Page 400
13.4.2 Risk identification......Page 404
13.4.3 Risk analysis......Page 406
13.4.4 Risk evaluation......Page 410
13.5.1 Overview......Page 411
13.5.3 Geotechnical control measures......Page 413
13.5.4 Mitigation plans......Page 414
13.5.5 Monitoring, review and feedback......Page 415
14.1 Introduction......Page 416
14.2.3 Closure planning for existing mines......Page 418
14.3.1 Closure goals and criteria......Page 420
14.3.2 Site characterisation......Page 422
14.3.3 Ore body characteristics and mining approach......Page 423
14.3.6 Pit lake water quality......Page 424
14.3.8 Pit wall stability......Page 425
14.5 Conclusions......Page 427
Endnotes......Page 428
Groundwater data collection......Page 430
Essential statistical and probability theory......Page 446
Evert Hoek, Jean Hutchinson, Kathy Kalenchuk and Mark Diederichs......Page 452
Risk management: geotechnical hazard checklists......Page 462
Example regulations for open pit closure......Page 474
Terminology and definitions......Page 477
References......Page 482
Index......Page 502
