Page 8 - Rock Mechanics For Underground Mining

CONTENTS

9 Excavation design in blocky rock 242

9.1 Design factors 242
9.2 Identification of potential block failure modes – Block Theory 243
9.3 Symmetric triangular roof prism 255
9.4 Roof stability analysis for a tetrahedral block 261
9.5 Design practice in blocky rock 263
9.6 Stope wall design – the Mathews stability chart method 266

10 Energy, mine stability, mine seismicity and rockbursts 271
10.1 Mechanical relevance of energy changes 271
10.2 Mining consequences of energy changes 275
10.3 Energy transmission in rock 277
10.4 Spherical cavity in a hydrostatic stress field 285
10.5 General determination of released and excess energy 289
10.6 Mine stability and rockbursts 293
10.7 Instability due to pillar crushing 294
10.8 Thin tabular excavations 299
10.9 Instability due to fault slip 301
10.10 Characterisation of seismic events 304

11 Rock support and reinforcement 312
11.1 Terminology 312
11.2 Support and reinforcement principles 313
11.3 Rock–support interaction analysis 317
11.4 Pre-reinforcement 322
11.5 Support and reinforcement design 326
11.6 Materials and techniques 338
12 Mining methods and method selection 347

12.1 Mining excavations 347
12.2 Rock mass response to stoping activity 349
12.3 Orebody properties influencing mining method 352
12.4 Underground mining methods 355
12.5 Mining method selection 368

13 Pillar supported mining methods 370
13.1 Components of a supported mine structure 370
13.2 Field observations of pillar performance 372
13.3 Elementary analysis of pillar support 375
13.4 Design of a stope-and-pillar layout 384
13.5 Bearing capacity of roof and floor rocks 390
13.6 The Elliot Lake room-and-pillar mines 391
13.7 Stope-and-pillar design in irregular orebodies 396
13.8 Open stope-and-pillar design at Mount Charlotte 403

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