Introduction to Geological Engineering

Geological Engineering

Luis I. González de Vallejo Universidad Complutense de Madrid

Mercedes Ferrer Instituto Geológìco y Minero de España

with a Foreword by M.H. de Freitas Imperial College, London

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CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business © 2011 Taylor & Francis Group, London, UK Typeset by Vikatan Publishing Solutions (P) Ltd, Chennai, India Printed and bound in Poland by Poligrafia Janusz Nowak, Poznán Authorized translation from the Spanish language edition, entitled INGENIERÍA GEOLÓGICA by GONZÁLEZ DE VALLEJO, LUIS, published by Pearson Educación, S.A. Copyright © Pearson Educación, S.A., 2002. English translation by Bill Newton, Pauline Moran and Valerie Stacey from Gabinete Lingüístico of the Fundación General de la ­Universidad Complutense de Madrid. English technical review by M.H. de Freitas, Imperial College, London. All rights reserved. No part of this publication or the information contained herein may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, by photocopying, recording or otherwise, without prior permission in writing from the publisher. Innovations reported here may not be used without the approval of the authors. Although all care is taken to ensure integrity and the quality of this publication and the information herein, no responsibility is assumed by the publishers nor the author for any damage to the property or persons as a result of operation or use of this publication and/or the information contained herein. Published by: CRC Press/Balkema P.O. Box 447, 2300 AK Leiden, The Netherlands e-mail: [email protected] www.crcpress.com – www.taylorandfrancis.co.uk – www.balkema.nl Library of Congress Cataloging-in-Publication Data Applied for ISBN: 978-0-415-41352-7 (Hbk)

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Brief CONTENTS ABOUT THE AUTHORS

xv

CONTRIBUTORS

xvii

FOREWORD

xix

PREFACE

xxi

PART I – FUNDAMENTALS   1 Introduction to Geological Engineering   2 Soil mechanics and engineering geology of sediments

3 19

  3 Rock mechanics

109

  4 Hydrogeology

223

PART II – METHODS   5 Site investigation

263

  6 Rock mass description and characterization

327

  7 Engineering geological mapping

351

PART III – APPLICATIONS   8 Foundations

369

  9 Slopes

401

10 Tunnels

451

11 Dams and reservoirs

501

12 Earth structures

535

PART IV – GEOLOGICAL HAZARDS 13 Landslides and other mass movements

555

14 Seismic hazard

595

15 Prevention of geological hazards

625

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vi

Brief CONTENTS

APPENDIX A Charts for circular and wedge failure analysis

643

APPENDIX B Pressure units conversion CHART

653

APPENDIX C Symbols and acronyms

657

APPENDIX D LIST OF BOXES

663

APPENDIX E PERMISSIONS TO REPRODUCE FIGURES AND TABLES

665

Index

671

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CONTENTS ABOUT THE AUTHORS

xv

CONTRIBUTORS

xvii

FOREWORD

xix

PREFACE

xxi

PART I – FUNDAMENTALS   1 INTRODUCTION TO GEOLOGICAL ­ENGINEERING

3

  1.1 Definition and importance of geological engineering

4

  1.2 The geological environment and its ­relation with engineering

6

  1.3 Geological factors and geotechnical problems

8

  1.4 Methods and applications in geological engineering

15

  1.5 Information sources in engineering ­geology

16

  1.6 How this book is structured

16

Recommended reading

17

References

17

  2 SOIL MECHANICS AND ENGINEERING GEOLOGY OF SEDIMENTS

19

  2.1 Introduction The nature of soils Soils in geotechnical engineering

20 20 20

  2.2 Soil description and classification. Phase relationships Types of soils Particle size distribution

23 23 23

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Plasticity Phase relationships

24 26

  2.3 Flow of water through soils 28 Total head. Bernoulli’s Theorem 29 Hydrostatic conditions 29 Ground water flow 30 Basic concepts. Head loss and permeability 30 Hydraulic head and hydraulic gradient 31 Darcy’s law 31 Steady flow in an isotropic medium 33 Anisotropic soil conditions 36 Permeability and water flow in stratified soils 38   2.4 Effective stress Soil phases and soil structure Saturated soils. The principle of effective stress Seepage forces and piping Loading saturated soils The concept of consolidation Concepts of loading with and without drainage Undrained loading in saturated soils

40 40 41 44 50 50 51 52

  2.5 Consolidation and compressibility Normally consolidated and overconsolidated soils Horizontal stresses in the ground Influence of complementary factors on soil behaviour The oedometer test

56

  2.6 Shear strength of soils Failure criterion The direct shear test Behaviour of soils subjected to shear stress Granular soils Clay soils The triaxial test The test apparatus

71 71 72 76 76 78 79 79

56 62 63 65

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Types of test The uniaxial compression test   2.7 Influence of mineralogy and fabric on the geotechnical properties of soils Clay minerals in engineering geology Physico-chemical properties Geotechnical properties and mineralogical ­composition Microfabric of clayey soils Geotechnical properties and microfabric Summary

81 85

85 86 88 89 89 93 94

  2.8 Engineering geological characteristics of sediments Colluvial deposits Alluvial deposits Lacustrine deposits Coastal deposits Glacial deposits Deserts and arid climate deposits Evaporitic deposits Tropical soils Volcanic soils

94 95 95 95 95 96 97 98 98 99

  2.9 Problematic soils Swelling and shrinking clays Dispersive soils Saline and aggressive soils Collapsible soils The action of ice and permafrost Soft sensitive soils Soils susceptible to liquefaction

100 101 103 104 104 106 106 106

Recommended reading

107

References

107

  3 ROCK MECHANICS

109

  3.1 Introduction Definition, objectives and scope Rock and soil Rock masses

110 110 112 113

  3.2 Physical and mechanical properties of rocks Rock characteristics Physical properties of intact rock Rock classification for geotechnical purposes Rock mass classification Weathering of rock

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116 116 118 122 124 125

Weathering processes Weathering of intact rock Weathering of rock masses Groundwater Permeability and water flow Effects of water on the properties of rock masses   3.3 Stress and strain in rocks Force and stress Stress on a plane Stress in three dimensions Strength and failure Basic concepts Failure mechanisms Stress-strain relationships in rock Strength criteria   3.4 Strength and deformability of intact rock Strength and strength parameters Effects of anisotropy and pore pressure on strength Failure criteria Mohr-Coulomb criterion Hoek-Brown’s criterion Deformability Strength and deformability laboratory tests Uniaxial compression test Triaxial compression test Tensile strength tests Sonic velocity Limitations of laboratory tests   3.5 Discontinuities Influence on rock mass behaviour Types of discontinuities Characteristics of discontinuities Shear strength of discontinuity planes Barton and Choubey criterion Discontinuities with infilling Direct shear strength laboratory test Permeability and water pressure   3.6 Strength and deformability of rock masses Rock mass strength Failure criteria for isotropic rock masses Failure criteria for anisotropic rock masses

125 126 127 129 129 129 131 131 132 138 139 139 140 141 144 147 147 147 149 149 150 150 154 154 159 162 164 164 165 165 166 168 170 172 175 175 177 179 179 181 186

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Summary Rock mass deformability In situ deformability tests Geophysical methods Empirical correlations Permeability and water pressure Scale effect   3.7 In situ stress Origin and types of in situ stress Geological and morphological factors which influence the state of stress Methods for measuring in situ stress Measuring the direction of stresses by ­geological methods Estimating stress magnitude from empirical relationships Instrumental methods for measuring ­orientation and magnitude of stress

187 187 188 188 189 193 195

Pumping tests Injection tests Tracer tests

238 248 249

  4.5 Solution methods Analytical methods Flow nets Numerical methods

251 251 252 253

  4.6 Chemical properties of water Chemical quality of groundwater Physical-chemical processes. Water-aquifer ­interaction Contamination of groundwater Anthropogenic activities Mechanisms of ground water contamination

255 255 256 257 257 258

207

Recommended reading and references

259

207

PART II – METHODS

201 201 203 205 206

  3.8 Rock mass classifications RMR Classification Geomechanical classifications in practice

215 216 216

Recommended reading

220

References

221

  4 Hydrogeology

223

  4.1 Hydrogeological behaviour of soils and rocks Types of aquifers and their behaviour Piezometric level Water movement in aquifers

224 224 227 228

  4.2 Hydrogeological parameters Porosity Storage coefficient Permeability Transmissivity

230 230 231 232 233

  4.3 Flow. Darcy’s law and fundamental flow equations in porous media Darcy’s law Darcy’s velocity and real velocity Generalization of Darcy’s law Continuity equation for steady flow Laplace equation Poisson’s equation Flow equation in transitory regime

233 233 234 235 236 236 237 237

  4.4 Evaluation methods for hydro­ geological parameters

238

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  5 SITE INVESTIGATION

263

  5.1 Planning and design Aims and importance Planning site investigations

264 264 264

  5.2 Preliminary investigations Desk-based study Aerial photo and remote sensing interpretation Aerial photo interpretation Remote sensing The walk-over survey Preliminary site investigation report

268 268 269 269 270 273 275

  5.3 Engineering geophysics Surface geophysics Electrical methods Seismic methods Electromagnetic methods Gravity methods Magnetic methods Borehole geophysics Geophysical logging Seismic logging inside boreholes Seismic tomography

275 276 276 277 282 285 285 286 286 287 288

  5.4 Boreholes, trial pits, trenches and sampling Borehole drilling Rotary drilling Auger drilling Percussion drilling

289 289 289 291 292

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contents

Special boreholes Number and depth of boreholes Borehole data presentation Trial excavations Geotechnical sampling Borehole logging

293 293 293 293 294 297

Filling Seepage

342 343

  6.5 Rock mass parameters Number and orientation of discontinuity sets Block size and fracture degree Degree of weathering

343 344 344 347

  6.6 Rock mass classification and ­characterisation

349

Recommended reading

349

References

350

  7 Engineering Geological Mapping

351

  7.1 Definition

352

  7.2 Types of maps Classification Content of engineering geological maps Classification and geotechnical properties of soils and rocks Hydrogeological conditions Geomorphological conditions Geodynamic processes

352 352 354 354 357 357 357

  7.3 Mapping methods Geotechnical zoning Representing data Computer aided mapping Geotechnical cross-sections

358 358 358 360 360

  7.4 Data collection

360

  7.5 Applications Land and urban planning Engineering

361 361 361

Recommended reading

365

References

365

  5.5 In situ tests Standard penetration test (SPT) Probing penetrometers Cone penetration test (CPT) Field vane test Schmidt hammer test Point load test Shear strength test on discontinuities Tilt test Pressuremeter test Plate loading test on soils Dilatometer test Plate loading test on rock Flat jack test Seismic methods Measuring in situ stress Permeability tests Permeability tests on soils Permeability tests on rock

301 301 302 303 305 305 306

  5.6 Geotechnical instrumentation Displacement measurements Pore pressure and water level measurements Stress measurements

319 319

Recommended reading

325

References

325

  6 ROCK MASS DESCRIPTION AND ­CHARACTERISATION

327

  6.1 Methodology

328

  6.2 Description and zoning

331

PART III – APPLICATIONS

  6.3 Intact rock characterisation Identification Weathering Strength

331 332 332 332

  8 Foundations

369

  6.4 Description of discontinuities Orientation Spacing Persistence Roughness Strength of discontinuity wall Aperture

335 335 336 337 338 340 341

  8.1 Introduction Basic design criteria Stages in foundation design

370 370 371

  8.2 Shallow foundations Types of shallow foundations Ultimate bearing capacity Basic definitions Calculating the ultimate bearing capacity

371 371 372 372

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308 310 311 311 312 313 313 316 316 316 316 317

322 324

373

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Ultimate bearing capacity in undrained ­conditions Ultimate bearing capacity in drained ­conditions Factor of safety. Safe bearing capacity Distribution of pressures under shallow ­foundations Stress distribution under loaded areas Fundamentals. Criteria for use Point load on an elastic half-space Vertical stresses under the corner of a ­uniformly loaded rectangle Stresses under a uniformly loaded circular area Settlement in soils General considerations Immediate and consolidation settlement Immediate and primary consolidation ­settlements in saturated clays Settlements in granular soils Settlements in stiff clays

374 375 375 376 378 378 379 379 380 382 382 382 383 384 384

Geological structure and discontinuities Hydrogeological conditions Geomechanical properties of soil and rock masses In situ stresses Other factors

404 405 408 408 409

  9.4 Types of slope failure Soil slopes Rock slopes Plane failure Wedge failure Toppling Buckling Non-planar failure

410 410 411 411 412 413 414 414

  9.5 Stability analysis Introduction Limit equilibrium methods Soil slopes Rock slopes Stress-strain methods Geomechanical slope classification Slope mass rating (SMR)

415 415 415 417 426 432 433 433

  9.6 Stabilization measures Introduction Stabilization methods Modifying the geometry Drainage methods Resistant structural elements Walls and retaining elements Surface protection measures

434 434 435 435 436 439 440 441

  9.7 Monitoring and control

443

  9.8 Slope excavation Rippability criteria

445 447

Recommended reading

449

References

449

10 Tunnels

451

10.1 Introduction

452

  8.3 Deep foundations Types of pile Single piles Ultimate load capacity of a pile Pile groups Negative friction on piles Laterally loaded piles

385 386 387 389 391 391 392

  8.4 Foundations on rock

392

  8.5 Foundations in complex geological ­conditions Expansive soils Collapsible soils Karstic cavities Volcanic cavities Soft and organic soils Anthropogenic fills

394 394 396 396 396 397 397

  8.6 Site investigation Stages in site investigations

398 398

Recommended reading

400

10.2 Site investigation

453

References

400

  9 SLOPES

401

  9.1 Introduction

402

  9.2 Site investigations

403

  9.3 Factors influencing slope stability Stratigraphy and lithology

404 404

10.3 Influence of geological conditions Geological structure Discontinuities Intact rock strength Hydrogeological conditions In situ stress Methods of analysis Effects of high stress on tunnelling

454 457 458 459 460 461 462 464

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10.4 Geomechanical design parameters Geological and geomechanical data Strength and deformability Magnitude and direction of in situ stress Estimation of K from the TSI index Sheorey’s method Water inflow and pressure 10.5 Rock mass classifications for tunnelling Q System SRC rock mass classification Suggested criteria for the application of rock mass classifications

464 464 465 466 466 471 471 472 472 476 480

10.6 Tunnel support design using rock mass classifications Tunnel support based on RMR classification Tunnel support based on the Q index

481 483

10.7 Excavability

483

10.8 Tunnel excavation and support methods in rock Excavation methods Stages of excavation Support systems Ground improvement The New Austrian Tunnelling Method Portals

484 487 489 489 491 491 492

10.9 Tunnel excavation and support methods in soil Non-mechanical excavation methods Semi-mechanical excavation methods Tunnel excavation with tunnel boring machines

480

493 493 493 494

10.10 Geological engineering during tunnel construction

495

Recommended reading

499

References

499

11 DAMS AND RESERVOIRS

501

11.1 Introduction

502

11.2 Types of dams and auxiliary structures Types of dams Embankment dams Concrete dams Auxiliary structures

503 503 504 504 506

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11.3 Site investigation Planning site investigation Preliminary and feasibility studies Selecting the type of dam Design Construction Operation Site investigation methods

507 507 508 508 508 508 509 509

11.4 Engineering geological criteria for dam selection General criteria Foundation conditions Availability of materials Siting of auxiliary structures Conditions for embankment dams Conditions for concrete dams Environmental considerations

513 513 513 514 514 515 515 515

11.5 Geological materials for dam ­construction Site investigations for dam materials Types of materials Cores Rockfills and ripraps Filters and drains Aggregates

516 516 516 516 517 517 517

11.6 Reservoir water tightness

518

11.7 Permeability of dam foundations Uplift pressures Erosion Leakage control

519 519 519 521

11.8 Reservoir slope stability

521

11.9 Engineering geological conditions for dam foundations General conditions Loads on dam foundations Dam foundation failure mechanisms Stress distributions in dam foundations Foundation improvement measurements Dam foundation problems and possible remedial measures

523 523 523 524 527 528 529

11.10 Seismic actions and induced seismicity

532

Recommended reading

533

References

533

12 Earth Structures

535

12.1 Introduction

536

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12.2 Design methodology

537

12.3 Materials Earthfill embankments Rockfill embankments Coarse rockfill

540 540 541 545

12.4 Implementation and control

545

12.5 Embankments on soft soils

548

12.6 Embankments on slopes

550

References and recommended reading

551

PART IV – GEOLOGICAL HAZARDS 13 Landslides and other Mass  Movements

555

13.1 Introduction

556

13.2 Slope movements Types of slope movements Landslides Flows Rock falls Rock avalanches Lateral displacements Causes of slope movements Rainfall and climatic conditions Changes in water level Erosion Earthquakes Volcanism Human actions

556 557 557 560 561 562 562 563 565 567 567 568 569 569

13.3 Investigation of landslides General field surveys Analysis of the processes Detailed investigations Stability analysis Monitoring Alarm systems

570 570 574 576 580 581 582

13.4 Corrective measures Stabilisation and protection against rock falls

582

13.5 Collapse and subsidence Types of movements and their causes Collapse Subsidence Investigation of the processes Corrective measures

585 585 586 587 587 589

13.6 Prevention of risks from mass ­movements

589

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583

Susceptibility and hazard maps Slope movement maps Collapse and subsidence maps

591 591 592

Recommended reading

593

References

593

14 SEISMIC HAZARD

595

14.1 Introduction

596

14.2 Faults and earthquakes Faults as the source of earthquake Stick-slip regimes and the seismic cycle The seismic fault model Slip rates and recurrence periods Geological recording of fault activity The study of seismic faults

596 596 597 598 599 600 600

14.3 Seismicity studies

604

14.4 Seismic hazard analysis Deterministic method Probabilistic methods

606 606 608

14.5 Seismic site response Design earthquake Seismic parameters of ground motion Modification of ground motion by local ­conditions

609 610 610

14.6 Ground effects induced by earthquakes Liquefaction potential Landslides induced by earthquakes Fault rupture 14.7 Applications to geological engineering Seismic hazard studies applied to site assessment Seismic microzonation Seismic vulnerability assessment

xiii

611 613 613 615 616 617 617 617 619

Recommended reading

622

References

622

15 Prevention of Geological Hazards 625 15.1  Geological hazards

626

15.2 Hazard, risk and vulnerability

627

15.3 Safety criteria in geological engineering

631

15.4  Prevention and mitigation of geological hazards

638

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15.5 Hazard and risk maps

639

Recommended reading

641

References

642

APPENDIX A Charts for circular and wedge failure analysis

643

APPENDIX B Pressure units conversion chart

653

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APPENDIX C Symbols and acronyms

657

APPENDIX D LIST OF BOXES

663

APPENDIX E PERMISSIONS TO REPRODUCE FIGURES AND TABLES

665

Index

671

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