Preface ....................................................... xiv
Acknowledgements ............................................... xv
About the author .............................................. xvi
1 Engineering geology .......................................... 1
1.1 Introduction ............................................ 1
1.2 What do engineering geologists do? ...................... 1
1.3 What an engineering geologist needs to know ............. 2
1.4 The role of an engineering geologist in a project ....... 5
1.4.1 General .......................................... 5
1.4.2 Communication within the geotechnical team ....... 5
1.5 Rock and soil as engineering materials .................. 9
1.6 Qualifications and training ............................ 11
2 Introduction to civil engineering projects .................. 14
2.1 Management: parties and responsibilities ............... 14
2.1.1 The owner/client/employer ....................... 14
2.1.2 The architect and engineer ...................... 14
2.1.3 The project design .............................. 16
2.1.4 The contractor .................................. 17
2.1.5 Independent checking engineer ................... 18
2.2 Management: contracts .................................. 18
2.2.1 Risk allocation for geotechnical conditions ..... 19
2.2.2 Reference ground conditions ..................... 21
2.2.3 Claims procedures ............................... 23
2.2.4 Dispute resolution .............................. 24
2.2.5 Legal process and role of expert witness ........ 25
2.2.6 Final word on contracts: attitudes of parties ... 26
2.3 Design of structures: an introduction .................. 27
2.3.1 Foundations ..................................... 27
2.3.1.1 Loading from a building ................ 27
2.3.1.2 Options for founding structures ........ 29
2.3.2 Tunnels ......................................... 31
2.4 Design: design codes ................................... 33
2.5 Design: application of engineering geological
principles ............................................. 36
3 Geology and ground models ................................... 38
3.1 fggp&teept of modelling ................................ 38
3.1.1 Introduction .................................... 38
3.2 Relevance of geology to engineering .................... 40
3.3 Geological reference models ............................ 41
3.3.1 A holistic approach ............................. 41
3.3.2 The need for simplification and classification .. 42
3.3.3 Igneous rocks and their associations ............ 43
3.3.4 Sediments and associations - soils and rocks .... 46
3.3.4.1 General nature and classification ...... 46
3.3.4.2 Sedimentary environments ............... 52
3.3.5 Metamorphic rocks and their associations ........ 60
3.4 Geological structures .................................. 63
3.4.1 Introduction .................................... 63
3.4.2 Types of discontinuity .......................... 64
3.4.3 Geological interfaces ........................... 64
3.4.4 Faults .......................................... 64
3.4.5 Periglacial shears .............................. 67
3.4.6 Joints .......................................... 67
3.4.7 Differentiation into sets ....................... 73
3.4.8 Orthogonal systematic ........................... 74
3.4.9 Non-orthogonal, systematic ...................... 76
3.4.10 Shear joints .................................... 78
3.4.11 Complex geometries .............................. 78
3.4.12 Sheeting joints ................................. 80
3.4.13 Morphology of discontinuity surfaces ............ 84
3.4.13.1 Sedimentary rocks ..................... 85
3.4.13.2 Tension fractures ..................... 86
3.5 Weathering ............................................. 87
3.5.1 Weathering processes ............................ 87
3.5.2 Weathering profiles ............................. 88
3.6 Water .................................................. 91
3.6.1 Introduction .................................... 91
3.6.2 Groundwater response to rainfall ................ 92
3.6.3 Preferential flow paths through soil ............ 94
3.6.4 Preferential flow paths through rock ............ 95
3.7 Geological hazards ..................................... 96
3.7.1 Introduction .................................... 96
3.7.2 Landslides in natural terrain ................... 97
3.7.2.1 Modes of failure ....................... 97
3.7.2.2 Slope deterioration and progressive
failure ................................ 98
3.7.3 Earthquakes and volcanoes ...................... 100
3.8 Ground models for engineering projects ................ 100
3.8.1 Introduction ................................... 100
3.8.2 General procedures for creatine a model ........ 102
3.8.3 Fracture networks .............................. 103
3.8.4 Examples of models ............................. 103
4 Site investigation ......................................... 115
4.1 Nature of site investigation .......................... 115
4.2 Scope and extent of ground investigation .............. 116
4.2.1 Scope and programme of investigation ........... 116
4.2.2 Extent of ground investigation ................. 119
4.3 Procedures for site investigation ..................... 124
4.3.1 General ........................................ 124
4.3.2 Desk study ..................................... 124
4.3.2.1 Sources of information ................ 124
4.3.2.2 Air photograph interpretation ......... 125
4.3.3 Planning a ground investigation ................ 128
4.3.3.1 Equation 1: geological factors ........ 129
4.3.3.2 Equation 2: environmental factors ..... 135
4.3.3.3 Equation 3: construction-related
factors ............................... 136
4.3.3.4 Discussion ............................ 137
4.4 Field reconnaissance and mapping ...................... 139
4.4.1 General ........................................ 139
4.4.2 Describing field exposures ..................... 143
4.5 Geophysics ............................................ 151
4.5.1 Seismic methods ................................ 152
4.5.2 Resistivity .................................... 153
4.5.3 Other techniques ............................... 153
4.5.4 Down-hole geophysics ........................... 154
4.6 Sub-surface investigation ............................. 154
4.6.1 Sampling strategy .............................. 154
4.6.2 Boreholes in soil .............................. 155
4.6.3 Rotary drilling ................................ 158
4.7 In situ testing ....................................... 161
4.8 Logging borehole samples .............................. 168
4.9 Down-hole logging ..................................... 172
4.10 Instrumentation ....................................... 174
4.11 Environmental hazards ................................. 179
4.11.1 General ........................................ 179
4.11.2 Natural terrain landslides ..................... 180
4.11.3 Coastal recession .............................. 181
4.11.4 Subsidence and settlement ...................... 182
4.11.5 Contaminated land .............................. 182
4.11.6 Seismicity ..................................... 183
4.11.6.1 Principles ............................ 183
4.11.6.2 Design codes ......................... 183
4.11.6.3 Collecting data ...................... 183
4.12 Laboratory testing .................................... 184
4.13 Reporting ............................................. 184
5 Geotechnical parameters .................................... 185
5.1 Physical properties of rocks and soils ................ 185
5.2 Material vs. mass ..................................... 185
5.3 Origins of properties ................................. 185
5.3.1 Fundamentals ................................... 185
5.3.2 Friction between minerals ...................... 187
5.3.3 Friction of natural soil and rock .............. 187
5.3.4 True cohesion .................................. 189
5.3.5 Geological factors ............................. 189
5.3.5.1 Weathering ............................. 190
5.3.5.2 Diagenesis and lithification
(formation of rock from soil) ......... 191
5.3.5.3 Fractures ............................. 193
5.3.5.4 Soil and rock mixtures ................ 193
5.4 Measurement methods ................................... 195
5.4.1 Compressive strength ........................... 196
5.4.2 Tensile strength ............................... 201
5.4.3 Shear strength ................................. 201
5.4.3.1 True cohesion .......................... 203
5.4.3.2 Residual strength ...................... 203
5.4.4 Deformability .................................. 204
5.4.5 Permeability ................................... 204
5.5 Soil properties ....................................... 205
5.5.1 Clay soils ..................................... 205
5.5.2 Granular soil .................................. 207
5.5.3 Soil mass properties ........................... 207
5.6 Rock properties ....................................... 207
5.6.1 Intact rock .................................... 207
5.6.1.1 Fresh to moderately weathered rock .... 207
5.6.1.2 Weathered rock ........................ 208
5.6.2 Rock mass strength ............................. 209
5.6.3 Rock mass deformability ........................ 211
5.7 Rock discontinuity properties ......................... 213
5.7.1 General ........................................ 213
5.7.2 Parameters ..................................... 214
5.7.3 Shear strength of rock joints .................. 215
5.7.3.1 Basic friction, Φb .................... 215
5.7.3.2 Roughness ............................. 221
5.7.4 Infilled joints ............................... 222
5.7.5 Estimating shear strength using empirical
methods ........................................ 223
5.7.6 Dynamic shear strength of rock joints .......... 225
5.8 Rock-soil mixes ....................................... 226
5.8.1 Theoretical effect on shear strength of
included boulders .............................. 227
5.8.2 Bearing capacity of mixed soil and rock ........ 228
5.9 Rock used in construction .............................. 228
5.9.1 Concrete aggregate ............................. 228
5.9.2 Armourstone .................................... 229
5.9.3 Road stone ..................................... 229
5.9.4 Dimension stone ................................ 229
6 Analysis, design and construction .......................... 231
6.1 Introduction .......................................... 231
6.2 Loads ................................................. 231
6.2.1 Natural stress conditions ...................... 231
6.2.2 Loadings from a building ....................... 236
6.3 Temporary and permanent works ......................... 237
6.4 Foundations ........................................... 238
6.4.1 Shallow foundations ............................ 238
6.4.2 Buoyant foundations ............................ 241
6.4.3 Deep foundations ............................... 242
6.4.3.1 Piled foundations ..................... 242
6.4.3.2 Design ................................ 245
6.4.3.3 Prooftesting .......................... 251
6.4.3.4 Barrettes ............................. 251
6.5 Tunnels and caverns ................................... 253
6.5.1 General considerations for tunnelling .......... 253
6.5.2 Options for construction ....................... 254
6.5.3 Soft ground tunnelling ......................... 255
6.5.4 Hard rock tunnelling ........................... 258
6.5.4.1 Drill and blast/roadheaders ........... 258
6.5.4.2 TBM tunnels in rock ................... 260
6.5.5 Tunnel support ................................. 260
6.5.5.1 Temporary works ....................... 260
6.5.5.2 Permanent design ...................... 261
6.5.6 Cavern design .................................. 265
6.5.7 Underground mining ............................. 266
6.5.8 Risk assessments for tunnelling and
underground works .............................. 266
6.5.8.1 Assessment at the design stage ........ 267
6.5.8.2 Risk registers during construction .... 267
6.6 Slopes ................................................ 268
6.6.1 Rock slopes ..................................... 268
6.6.1.1 Shallow failures ...................... 269
6.6.1.2 Structural ............................ 272
6.6.1.3 Deep-seated failure ................... 274
6.6.2 Soil slopes .................................... 274
6.6.3 Risk assessment ................................ 279
6.6.4 General considerations ......................... 279
6.6.5 Engineering options ............................ 281
6.6.5.1 Surface treatment ..................... 281
6.6.5.2 Rock and boulder falls ................ 282
6.6.5.3 Mesh .................................. 283
6.6.5.4 Drainage .............................. 283
6.6.5.5 Reinforcement ......................... 285
6.6.5.6 Retaining walls and barriers .......... 286
6.6.5.7 Maintenance ........................... 287
6.7 Site formation, excavation and dredging ............... 288
6.7.1 Excavatability ................................. 288
6.7.2 Dredging ....................................... 288
6.8 Ground improvement .................................... 288
6.8.1 Introduction ................................... 288
6.8.2 Dynamic compaction ............................. 289
6.8.3 Static preloading .............................. 289
6.8.4 Stone columns .................................. 290
6.8.5 Soil mixing and jet-grouted columns ............ 290
6.8.6 Drainage ....................................... 290
6.8.7 Geotextiles .................................... 291
6.8.7.1 Strengthening the ground .............. 291
6.8.7.2 Drainage and barriers ................. 291
6.8.8 Grouting ....................................... 292
6.8.9 Cavities ....................................... 292
6.9 Surface mining and quarrying .......................... 293
6.10 Earthquakes ........................................... 294
6.10.1 Ground motion .................................. 294
6.10.2 Liquefaction ................................... 296
6.10.3 Design of buildings ............................ 297
6.10.4 Tunnels ........................................ 299
6.10.5 Landslides triggered by earthquakes ............ 300
6.10.5.1 Landslide mechanisms .................. 300
6.10.5.2 Empirical relationships ............... 302
6.10.6 Slope design to resist earthquakes ............. 303
6.10.6.1 Pseudo-static load analysis ........... 304
6.10.6.2 Displacement analysis ................. 304
6.11 Construction vibrations ............................... 304
6.11.1 Blasting ....................................... 304
6.11.2 Piling vibrations .............................. 305
6.12 Numerical modelling for analysis and design ........... 305
6.12.1 General purpose ................................ 305
6.12.2 Problem-specific software ...................... 306
6.13 Role of engineering geologist during construction ..... 307
6.13.1 Keeping records ................................ 307
6.13.2 Checking ground model and design assumptions ... 307
6.13.3 Fraud .......................................... 309
7 Unexpected ground conditions and how to avoid them: case
examples ................................................... 310
7.1 Introduction .......................................... 310
7.2 Ground risks .......................................... 310
7.3 Geology: material-scale factors ....................... 311
7.3.1 Chemical reactions: Carsington Dam, UK ......... 311
7.3.2 Strength and abrasivity of flint and chert:
gas storage caverns Killingholme, Humberside,
UK ............................................. 312
7.3.3 Abrasivity: TBM Singapore ...................... 312
7.3.4 Concrete aggregate reaction: Pracana Dam,
Portugal ....................................... 314
7.4 Geology: mass-scale factors ........................... 315
7.4.1 Pre-existing shear surfaces: Carsington Dam
failure ........................................ 315
7.4.2 Faults in foundations: Kornhill development,
Hong Kong ...................................... 316
7.4.3 Faults: TBM collapse, Halifax, UK .............. 316
7.4.4 Geological structure: Ping Lin Tunnel, Taiwan .. 318
7.4.5 Deep weathering and cavern infill: Tung
Chung, Hong Kong ............................... 318
7.4.6 Predisposed rock structure: Pos Selim
landslide, Malaysia ............................ 320
7.5 General geological considerations ..................... 322
7.5.1 Tunnel liner failure at Kingston on Hull, UK ... 322
7.5.2 Major temporary works failure: Nicoll
Highway collapse, Singapore .................... 323
7.5.3 General failings in ground models .............. 324
7.6 Environmental factors ................................. 324
7.6.1 Incorrect hydrogeological ground model and
inattention to detail: landfill site in the
UK ............................................. 324
7.6.2 Corrosive groundwater conditions and failure
of ground anchors: Hong Kong and UK ............ 327
7.6.3 Explosive gases: Abbeystead, UK ................ 328
7.6.4 Resonant damage from earthquakes at great
distance: Mexico and Turkey .................... 328
7.7 Construction factors .................................. 330
7.7.1 Soil grading and its consequence: piling at
Drax Power Station, UK ......................... 330
7.7.2 Construction of piles in karstic limestone,
Wales, UK ...................................... 332
7.8 Systematic failing .................................... 333
7.8.1 Heathrow Express Tunnel collapse ............... 333
7.8.2 Planning for a major tunnelling system under
the sea: SSDS Hong Kong ........................ 336
7.8.3 Inadequate investigations and mismanagement:
the application for a rock research
laboratory, Sellafield, UK ..................... 339
7.8.4 Landslide near Busan, Korea .................... 341
7.8.5 A series of delayed landslides on Ching
Cheung Road, Hong Kong ......................... 342
Appendix A: Training, institutions and societies .............. 344
A.l Training .............................................. 344
A.1.1 United Kingdom ................................. 344
A.1.2 Mainland Europe ................................ 345
A.1.3 United States of America ....................... 346
A.1.4 Canada ......................................... 347
A.1.5 China .......................................... 348
A.1.6 Hong Kong ...................................... 349
A.2 Institutions ........................................... 349
A.2.1 Introduction ................................... 349
A.2.2 The Institution of Geologists (IG) ............. 350
A.2.3 The Institution of Civil Engineers (ICE) ....... 351
A.2.3.1 Member ................................. 351
A.2.3.2 Fellow ................................. 351
A.2.4 Institution of Materials, Minerals and
Mining (IOM3) .................................. 352
A.2.5 Other countries ................................ 352
A.3 Learned societies ..................................... 352
A.3.1 Introduction ................................... 352
A.3.2 Geological Society of London ................... 352
A.3.3 International Association for Engineering
Geology and the Environment .................... 353
A.3.4 British Geotechnical Association (BGA) ......... 353
A.3.5 Association of Geotechnical and
Geoenvironmental Specialists ................... 353
A.3.6 International Society for Rock Mechanics ....... 354
A.3.7 International Society for Soil Mechanics and
Geotechnical Engineering ....................... 354
Appendix B: Conversion factors (to 2 decimal places) and
some definitions ........................................... 356
Appendix C: Soil and rock terminology for description
and classification for engineering purposes ................ 359
C.l Warning ............................................... 359
C.2 Introduction and history .............................. 359
C.3 Systematic description ................................ 360
C.3.1 Order of description ........................... 360
C.3.1.1 Soil ................................... 361
C.3.1.2 Rock ................................... 361
C.4 Soil description ...................................... 362
С.5 Rock description and classification ................... 362
C.5.1 Strength ....................................... 362
C.5.2 Joints and discontinuities ..................... 365
C.5.3 Discussion ..................................... 368
C.5.4 Weathering ..................................... 368
C.5.4.1 Material weathering classifications ... 369
C.5.4.2 Mass weathering classifications ....... 371
C.6 Rock mass classifications ............................. 374
C.6.1 RQD ............................................ 374
C.6.2 More sophisticated rock mass classification
schemes ........................................ 375
C.6.2.1 RMR ................................... 375
C.6.2.2 Q SYSTEM .............................. 376
C.6.2.3 GSI ................................... 376
C.6.3 Slope classifications .......................... 378
Appendix D: Examples of borehole and trial pit logs ........... 379
D.l Contractor's borehole logs ............................ 379
D.l.l UK example ..................................... 379
D.1.2 Hong Kong example .............................. 384
D.2 Consultant's borehole log, Australia .................. 384
D.3 Contractor's trial pit logs ........................... 393
Appendix E: Tunnelling risk ................................... 394
Appendix E-l Example of tunnelling risk assessment
at project option stage for Young Dong
Mountain Loop Tunnel, South Korea ..................... 394
Appendix E-2 Example of hazard and risk prediction
table ................................................. 401
Appendix E-3 Example risk register ......................... 415
References .................................................... 417
Index ......................................................... 443
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