Engineering Design in Geotechnics

Geotechnical design has evolved in line with technological advances which are being constantly refined. In fact, the new design trends have resulted in the generation of a new breed of specialist geotechnical contractors capable of executing design requirements in the most challenging soil conditions. In this respect, the use of Tunnel Boring Machines (TBMs) is no longer limited to large projects such as the Channel Tunnel; instead, tunnelling machines are available in any specified diameter, allowing for the execution of tunnels with diameters varying between 100 mm and 14 m, in any ground conditions. Equally, automated piling equipment is capable of drilling, concreting and reinforcing a 10 m deep, 360 mm diameter pile in less than 15 minutes. On the other hand, the use of pressuremeter and centrifuge testing for design purposes is becoming more of a norm in geotechnical design, making it essential to develop and adopt new design methodologies to keep up with these techniques. Engineering Design in Geotechnics includes the latest analytical tools directly linked to modern geotechnical practice. As such, the book which contains in excess of 300 state of the art illustrations and more than 50 worked examples, is an essential text for students and practising engineers alike.

Table of Contents:
Preface List of main symbols Conversion factors Acknowledgements 1. Engineering properties of soils p.1 - 1.1 Physical properties of soils p.1 - 1.2 Particle size analysis p.7 - 1.3 Statistical analysis of the grain size distribution: the phi-method p.11 - 1.4 Classification of fine-grained soils p.15 - 1.5 Soil compaction p.20 - 1.6 Practical aspects of soil compaction p.23 - 1.7 Collapsible soils p.26 - 1.8 Methods of deep compaction p.28 Problems p.31 References p.33 2. Shear strength of soils and rock masses p.34 - 2.1 Peak, critical and residual strengths p.34 - 2.2 Mohr's circle representation of stresses p.35 - 2.3 Stress-strain relationships at failure p.37 * Effective stress analysis p.37 * Total stress analysis p.42 - 2.4 Shear strength of coarse-grained soils p.44 - 2.5 Shear strength of fine-grained soils p.47 * The triaxial apparatus p.47 * State of a clay sample prior to testing p.48 * Undrained shear strength of saturated clays p.51 * Drained shear strength of saturated clays p.56 - 2.6 Quality assurance related to triaxial testing p.64 - 2.7 The shear vane test p.72 - 2.8 Shear strength of rocks p.76 - 2.9 Engineering properties of soils & rocks p.82 Problems p.84 References p.86 3. The stability of slopes p.87 - 3.1 Slope instability p.87 - 3.2 Stability of infinite slopes p.90 - 3.3 Effect of cohesion on the stability of infinite slopes p.94 - 3.4 Undrained analysis of the stability of infinite slopes p.95 - 3.5 Stability of slopes with circular failure surface p.96 * Total stress analysis p.96 * Effective stress analysis: Bishop's procedure p.98 * Effect of seepage forces on the stability of slopes p.108 - 3.6 Location of the critical failure surface p.111 - 3.7 Non-circular failure surface p.112 - 3.8 Improving the stability of unsafe slope p.113 * Use of geotextile reinforcement p.113 * Use of soil nails and rock bolts p.118 * Use of micropiles p.124 Problems p.127 References p.131 4. Limit analysis applied to the bearing capacity of shallow foundations p.132 - 4.1 Introduction p.132 - 4.2 The upper & lower bounds theorems p.133 - 4.3 Kinematically admissible collapse mechanisms: undrained behaviour p.134 - 4.4 Statically admissible stress fields: undrained behaviour p.137 - 4.5 Kinematically admissible collapse mechanisms: drained behaviour p.143 - 4.6 Statically admissible stress fields: drained behaviour p.145 - 4.7 Effects of soil weight and cohesion p.151 - 4.8 Effects of foundation shape & depth and load inclination p.154 - 4.9 Effects of load eccentricity p.159 * One way eccentricity p.159 * Two-way eccentricity p.161 Problems p.164 References p.169 5. Design of pile foundations p.171 - 5.1 Type of piles p.171 - 5.2 Pile testing p.178 - 5.3 Ultimate loading capacity of axially loaded single piles: the static method of design p.184 * General considerations p.184 * Undrained carrying capacity of single piles in clay p.186 * Drained carrying capacity of single piles in clay p.190 * Carrying capacity of single piles embedded in sand p.196 - 5.4 Negative skin friction p.201 - 5.5 Ultimate carrying capacity of pile groups p.205 * Group effect p.205 * Carrying capacity of piled foundations embedded in clays: undrained analysis p.208 * Design of free standing pile groups embedded in clays p.214 * Design of pile groups in sand: drained analysis p.215 * Negative skin friction on pile groups p.219 - 5.6 Settlement of single piles & pile groups p.226 - 5.7 Design of laterally loaded piles p.235 * Introduction p.235 * The subgrade reaction modulus method (aka Winkler model) p.237 Problems p.255 References p.260 6. Lateral earth pressure exerted on retaining walls p.263 - 6.1 Coefficient of earth pressure p.263 - 6.2 At rest stress conditions: coefficient Ko p.265 - 6.3 Active and passive stress conditions: Rankine theory p.267 - 6.4 Coulomb theory p.277 - 6.5 Boussinesq theory p.281 - 6.6 Lateral thrust due to different types of ground loading p.291 - 6.7 Effect of water pressure on the lateral thrust exerted on retaining structures p.294 - 6.8 Relevance of analytical solutions p.299 - 6.9 Boussinesq solution adapted to isotropic homogeneous backfill with uneven surface p.302 - 6.10 Coulomb solution adapted to multi-layered soils with uneven surface p.307 - 6.11 Critical appraisal of engineering practice p.314 - 6.12 Practical aspects of the design of retaining walls p.327 - 6.13 Stability criteria relating to the design of retaining walls p.328 Problems p.337 References p.341 7. Design of sheet pile and diaphragm walls p.344 - 7.1 Introduction p.344 - 7.2 Methods of design p.345 - 7.3 Design of anchored sheet piles using the modified free earth support method p.346 - 7.4 Design of anchored sheet piles using the fixed earth support method p.367 * Elastic line method p.367 * Blum's equivalent beam method p.368 - 7.5 Design of cantilever sheet pile walls p.378 Problems p.383 References p.386 8. Design of tunnels p.387 - 8.1 The stability of cylindrical cavities: equilibrium equation p.387 - 8.2 Stress analysis related to circular tunnels in clays and sand p.389 * Circular tunnels in fine-grained soils p.389 * Circular tunnels in granular soils p.392 - 8.3 Tunnelling in rocks p.394 - 8.4 Calculation of settlement induced by tunnelling p.401 * 3-D settlement p.401 * 2-D surface and subsurface settlement p.408 * Surface and subsurface settlement induced by microtunnelling p.412 - 8.5 Tunnelling methods in soft grounds p.413 * The sprayed concrete lining design method p.413 * Tunnel boring machines p.417 * The Channel Tunnel: case study p.423 Problems p.428 References p.431 9. finite element modelling in geomechanics p.433 - 9.1 FE modelling p.433 - 9.2 Effective stress analysis p.441 - 9.3 FE modelling of seepage and consolidation problems p.442 - 9.4 Practical aspects of FE modelling in geotechnics p.445 - 9.5 Practical aspects of a FE mesh related to foundations p.448 - 9.6 FE mesh related to embankments, retaining structures and tunnels p.452 References p.456 Index p.457 Aide Memoire p.467

About the Author :
Fethi Azizi has a degree in civil Engineering, an MSc in Applied Mechanics, and a PhD in Geotechnics. He is Chartered Engineer, European Engineer, Chartered Mathematician, Fellow of the Institute of Mathematics & its Applications, and Member of the Institution of Civil Engineers in London. He has more than 20 years experience in geotechnics research and teaching acquired at the Laboratoire Central des Ponts et Chaussees in Paris, the University of Manitoba in Canada, the Queen's University in Belafst, and the University of Plymouth in England. His research interests also include finite element modelling in Glaciology and in Geocryology.