High Resolution Pressuremeters and Geotechnical Engineering: The measurement of small things (Applied Geotechnics)

"High Resolution Pressuremeters and Geotechnical Engineering focuses on pressuremeters with internal transducers that allow measurement of strength, stiffness and in situ reference stress. It outlines the principles and the basics of the technology, gives guidance on good practice and making reliable analysis, provides case studies, and compares the pressuremeter test with similar ones from other devices to enable engineers to make informed choices. A unique, up-to-date guide to high resolution pressuremeters with internal transducers. Contextualises analyses and advice to enable an informed choice of testing processes. Presents analyses previously unpublished in book form. This practical guide will suit professionals at the consultancy level, pressuremeter practitioners and site investigation companies"-- Provided by publisher. Cover Half Title Title Page Copyright Page Contents Preface Part 1 Making a start Louis Ménard The Self-Boring Expansion Pressuremeter Analysis Part 2 Where are we now? The need to go small Passive pressuremeters Presentation Notes References Author bios Chapter 1: Introduction 1.1 Notation 1.2 Pressuremeters and dilatometers 1.3 Disturbance—selecting the appropriate tool 1.4 Unload/reload cycles 1.5 Why self-bore? 1.6 The pre-bored test in soil 1.7 The pushed test 1.8 Testing rock 1.9 Cavity expansion and the analytical approach 1.10 Principal stresses and the field curve 1.11 Measurement considerations—using the mean 1.12 Strain definitions 1.12.1 Simple strain 1.12.2 Current cavity strain 1.12.3 True or natural strain 1.12.4 Shear strain Notes References Chapter 2: Determining Modulus 2.1 Notation 2.2 Background 2.3 Describing the unload/reload cycle 2.4 Linear elastic interpretation 2.5 Non-linear stiffness/strain response 2.6 Stress level 2.6.1 Stress level in soils 2.6.2 Stress level in rocks 2.7 horizontal-vertical anisotropy 2.8 Shear modulus from other parts of the pressuremeter curve 2.9 Elastic (Young's) modulus, E 2.10 Bulk modulus (K or B) 2.11 Non-linear modulus in terms of shear stress 2.12 Possible methods for estimating Gmax and the threshold elastic shear strain 2.13 Normalisation 2.14 The limit of recoverability 2.15 Columbia Center, Seattle 2.16 Significant modulus relationships summarised Notes References Chapter 3: Analyses for in situ Lateral Stress 3.1 Notation 3.2 Overview 3.3 Lift-off 3.4 Marsland & Randolph (1977) yield stress analysis 3.5 Deriving parameters from the excess pore pressure trend 3.6 Deriving in situ lateral stress by curve modelling 3.7 Balance pressure check test 3.8 Lateral stress anisotropy 3.9 A note about ko — submerged measurements Note References Chapter 4: Analyses for Undrained Shear Strength 4.1 Notation 4.2 Introduction 4.3 Closed-form solutions 4.4 Non-linear elastic/perfectly plastic—Bolton & Whittle (1999) 4.5 Non-linear interpretation of pore water development 4.6 Analysing pressuremeter undrained contraction data 4.7 Palmer (1972) 4.7.1 Sensitive clays and liquefaction 4.7.2 Appropriate use of subtangent analysis 4.8 Undrained curve modelling of perfectly plastic data 4.8.1 Modelling the undrained test—Whittle (1999) 4.8.2 Applying the solution 4.8.3 The undrained model with pre-bored data 4.9 Houlsby & Withers (1988) 4.9.1 Houlsby & Withers (1988) adapted to account for non-linearity 4.10 Alternatives to the power law 4.11 Strength from limit pressure 4.12 Pressuremeters over-estimate shear strength? 4.13 Concluding remarks 4.14 Speculative correlations 4.14.1 Overconsolidation ratio 4.14.2 Inferring values for the angle of friction from undrained tests Notes References Chapter 5: Analyses for Drained Strength 5.1 Notation 5.2 Introduction 5.2.1 Drained cohesion 5.3 Drained curve modelling 5.4 Linear elastic/perfectly plastic solutions 5.4.1 Hughes et al. (1977) — cavity expansion 5.4.2 Houlsby et al. (1986) — cavity contraction 5.5 Incorporating non-linearity 5.5.1 Non-linear yield 5.5.2 Non-linear stress and strain below yield 5.5.3 Sensitivity of the model to parameter variation 5.6 Use with rock 5.7 Summarising the model 5.7.1 Using strain as input and finding the cavity pressure 5.7.2 Using pressure as input and finding the cavity strain 5.8 Carter et al. (1986) 5.8.1 Elastic strains in the plastic region 5.8.2 Deriving the limit pressure from Carter et al. (1986) 5.9 Manassero (1989) 5.9.1 Introduction 5.9.2 Derivation 5.9.3 Limit pressure — Ghionna et al. (1990) 5.9.4 Applying Manassero to cavity contraction — Whittle & Byrne (2020) 5.10 Testing loose sand 5.10.1 Testing for liquefaction susceptibility 5.11 Reconciling data — the state parameter and relative density Notes References Chapter 6: Hydraulic Conductivity and Consolidation 6.1 Notation 6.2 Introduction 6.3 Consolidation testing 6.3.1 Constant strain consolidation test example 6.3.2 Using total pressure data in a constant strain consolidation test 6.3.3 Time factors 6.4 Calculating consolidation—worked example 6.4.1 Using the pore pressure decay 6.4.2 Using the total pressure decay 6.4.3 Variation in the results 6.4.4 Other dissipation rates 6.4.5 Permeability coefficient from consolidation 6.5 Permeability testing 6.6 The permeability analysis 6.6.1 Scale 6.6.2 Potential issues with the testing method 6.6.3 Permeability or consolidation? References Chapter 7: Interpretation of Tests in Rock 7.1 Notation 7.2 Introduction 7.3 Pocket formation 7.4 Test procedure 7.5 The rock model 7.5.1 Proof load test 7.5.2 The determination of material properties from pressuremeter tests 7.5.3 Type (1) model: homogeneous/elastic 7.5.4 Type (2) model: elastic behaviour before failing in shear 7.5.5 Type 3, 4, 5 and 6 models: elastic, shear and tension 7.5.6 Influence of fluid in the hole 7.5.7 Summary of rock model 7.6 Deriving parameters in the presence of fractures 7.6.1 Modulus 7.6.2 Shear strength 7.6.3 Fracturing 7.7 Creep 7.7.1 Improvisation 7.8 Pore collapse 7.9 The difficulty of finding comparative data References Chapter 8: Miscellaneous Experiments with Pressuremeters: (experimental use of the cavity expansion test) 8.1 Notation 8.1.1 Introduction 8.2 Measuring the extent of the plastic zone 8.3 The sub-yield experiment 8.4 Measuring the elastic modulus with the load cell pressuremeter 8.5 Using pressuremeters to determine the deformation of landfill 8.6 Pulverised fuel ash (PFA) 8.7 Stresses around a deep tunnel References Epilogue Acknowledgements Data Notes Appendix A: Analytical Basis of the Pressuremeter Test: The stages of cavity expansion and contraction A.1 Notation A.2 Plane strain cavity loading A.2.1 Elastic strains A.2.2 Shear strains A.2.3 Stress equilibrium A.2.4 Strain equilibrium A.2.4.1 Strain compatibility A.2.5 Simple shear A.2.6 Initial observations A.3 Undrained deformation A.3.1 Shear stress from contraction data A.3.2 Circumferential stress A.4 Undrained case, closed-form solution A.4.1 Initial loading A.4.2 Plastic loading A.4.3 Tensile stresses A.4.4 Excess pore water pressure A.4.5 Conclusion for the undrained cavity expansion description A.5 Drained case, frictional material A.5.1 Linear yield A.5.2 Non-linear yield A.5.3 Drained yielding A.5.4 Limit pressure A.5.5 Conclusion for the drained cavity expansion description Notes References Appendix B: Technique, Equipment and Procedure B.1 Introduction B.2 Self-boring B.3 Drilling arrangements B.3.1 Self-boring with a cable percussion rig B.3.2 Self-boring with a rotary drill rig B.4 Drilling variables B.5 Self-boring test procedures B.5.1 Undrained B.5.2 Consolidation testing B.5.3 Drained B.5.4 Summary of requirements and considerations B.6 Pre-bored testing B.6.1 Complex hole preparation B.6.2 Expansion method B.6.3 Test procedures B.7 Pushing and reaming B.8 Deploying pressuremeters offshore B.8.1 Fixed platforms B.8.2 Floating platforms B.8.3 Wave action B.9 Losses Note Appendix C: Calibrating Cambridge Pressuremeters C.1 Introduction C.2 Scale factors C.3 The displacement measuring system C.4 Pressure-measuring transducers C.5 Reference ("zero") outputs C.6 Membrane stiffness C.7 Instrument compliance C.8 Instrument straightness C.9 Membrane thinning with strain C.10 Orientation C.11 Appropriate application of calibrations Appendix D: Comparing the Strain Distribution Around a Cone Penetrometer and Pressuremeter D.1 Introduction D.2 Experimental setup D.3 The results D.4 The pressuremeter D.4.1 Installation D.4.2 Cylindrical cavity expansion D.5 Conclusions Notes References Index