Geotechnical engineering is now a fundamental component of construction projects. The second volume of this book addresses the fundamental principles of soil mechanics and the role of water in geotechnical projects and assessments. Applied Geotechnics for Construction Projects 2 outlines the hydraulic properties of soils and the basic concepts of water in soil, detailing the principles of permeability measurement tests and giving concrete test cases, and then goes on to outline the basic notions of soil mechanics as applied in geotechnics: from consolidation to short- and long-term notions via the swelling phenomena of clayey soils, soil shear strength and slope stability. The third chapter presents a comprehensive overview of geotechnical expertise using examples of concrete projects either with or without damage in the context of geotechnical construction works.
Each chapter of this second volume provides concrete examples of applications to real projects and the rules and lessons we must remember. The result is a combination of geotechnical expertise and lessons learned from experience, both of which are highly valuable in the field of applied geotechnics for construction projects.
Table of Contents
Foreword ix
Philippe GUILLERMAIN† and François SCHLOSSER
Entrepreneur's Tribune: Geotechnics is at the Heart of Our Projects xi
Pascal LEMOINE and Eric DURAND
Preface xiii
Acknowledgments xix
Symbols and Notations xxi
Introduction lv
Chapter 1. Soil Hydraulics: On-Site Water Tests 1
1.1. Water in the soil: basics 1
1.1.1. General assumptions: water continuity condition in soil 1
1.1.2. Water velocity in soil 2
1.2. Darcy's law 4
1.2.1. Head of water 4
1.2.2. Hydraulic gradient 5
1.3. Generalization to flow networks 7
1.3.1. Three-dimensional medium: Laplace equation 7
1.3.2. Two-dimensional flow 8
1.4. Flow forces 10
1.4.1. Determination of flow forces 10
1.4.2. Critical gradient: boiling phenomenon 11
1.4.3. Role of pore pressures in soil 12
1.5. On-site measurement of soil permeabilities 13
1.5.1. Pumping test 14
1.5.2. Lefranc-type local permeability test 20
1.5.3. Lugeon tests: experimental analysis and practical interpretation 27
1.5.4. General conclusion 33
1.6. Practical applications 34
1.6.1. Interpretation of an actual pumping test 34
1.6.2. Interpretation of a real Lefranc-type test 38
1.6.3. Practical application of a Lugeon test 43
1.6.4. Experimental data: permeability of soils 44
1.6.5. Soil water level measurements: piezometers 47
1.6.6. Micro-reel permeability measurements 47
1.7. References 48
Chapter 2. Fundamental Principles of Soil Mechanics 51
2.1. Short-term and long-term soil behaviors 51
2.1.1. Concepts of short-term and long-term 51
2.1.2. Concepts of soil friction and cohesion 52
2.2. Soil consolidation and settlement 56
2.2.1. Preamble 56
2.2.2. Mechanical analogy 57
2.2.3. Oedometer tests 60
2.2.4. Terzaghi consolidation theory 65
2.2.5. Practical correlations between compressibility and creep parameters 76
2.3. Shear strength of soil 76
2.3.1. Preamble 76
2.3.2. Shear strength of granular soil 79
2.3.3. Shear strength of fine soil 80
2.3.4. Residual shear strength of soil 85
2.3.5. Corresponding states theorem 85
2.4. Swelling-shrinkage of clay soil 88
2.4.1. Preamble 88
2.4.2. Swelling-shrinkage mechanism 88
2.4.3. Geotechnical survey and diagnosis methodology 89
2.4.4. In the event of damage due to draught: structural solutions 95
2.5. Slope stability 99
2.5.1. Preamble 99
2.5.2. Landslide modes and their origins 100
2.5.3. Failure mechanisms 102
2.5.4. Stability calculation approaches 109
2.5.5. Studies and practical calculations of stability 114
2.5.6. Solutions for improving stability by water evacuation 116
2.6. Conventional safety coefficients 117
2.6.1. Definition of safety coefficient 117
2.6.2. Conventional values 118
2.7. Applications 122
2.7.1. Study of an embankment on soft soil: calculation of bearing capacity and settlements 122
2.7.2. Analysis of damage to a pavilion due to the swelling/shrinkage of clay 122
2.7.3. Parametric study of typical case stability 124
2.7.4. Correlations between compressibility parameters and test validity 127
2.7.5. Correlations between shear parameters 138
2.8. References 150
Chapter 3. Geotechnical Expertise 155
3.1. Preamble 155
3.2. Expertise on actual project cases 156
3.2.1. Housing project 157
3.2.2. Hospital center project 161
3.2.3. The issue of water 165
3.2.4. Predictions and measurements of the settlements of a thick raft of an HRB tower 170
3.2.5. Failure in a nailed wall of a motorway structure 178
3.3. Judicial expertise 183
3.3.1. Judicial expertise and the justice expert 183
3.3.2. Some cases of judicial expertise 186
3.4. Examples of rehabilitation (load balance) 211
3.4.1. Rehabilitation of a building on isolated footing 212
3.4.2. Rehabilitation of building on piles 213
3.5. Conclusion 216
3.6. References 218
French, European and ISO Standards in the Field of Geotechnics 221
Index 253
Summaries of Other Volumes 257
