Unsaturated Soil Mechanics in Geotechnical Practice - Rilegato

Blight, Geoffrey E

Rilegato

ISBN 10: 0415621186 ISBN 13: 9780415621182

Casa editrice: CRC Press, 2013

Riassunto

There are other books on unsaturated soil mechanics, but this book is different. Unsaturated soil mechanics is only one aspect of a continuous range of soil mechanics studies that extends from the rheology of high water content soil slurries to the mechanics of soft soils, to stiff saturated soils, to unsaturated soils, and, at the far end of the range, to dry soils.
In reality, the water content of all soils, that are not permanently submerged, varies seasonally. In most climatic zones, rainfall varies during the year and the depth of the water table varies sympathetically. In applying unsaturated soil mechanics in practice, it is therefore important to realise and allow for the probability that soil will, either seasonally or occasionally, pass from the unsaturated to the saturated state and even from unsaturation to dryness. This is the only book that looks specifically at this essential practical aspect.
The theory of unsaturated soils is fully dealt with in all of its aspects, including its application to natural undisturbed soils and compacted soils. Application of the theory to soil-like materials such as mine waste and municipal solid waste is also covered. Application of the theory to practice is illustrated by a number of detailed case histories. Unsaturated soil mechanics principles can also successfully and usefully be applied in related fields such as the bulk storage of particulate materials, underground mine support, solution mining and concrete structures. Several case histories are given that illustrate these practical applications.
The author has been professionally engaged in practical research and application of unsaturated soil mechanics for close to 60 years and with this book shares his wide experience with the reader.

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L'autore:

Geoffrey Blight completed his Bachelor and Master degrees at the University of the Witwatersrand, Johannesburg, and his PhD at Imperial College, London. There he carried out some of the earliest research on the mechanics of unsaturated soils, under the supervision of the legendary Alan Bishop. His early work, published jointly with Bishop and others in 1960, 1961 and 1963, provided data that is still being used by new generations of researchers on unsaturated soil behaviour. He soon became interested in the application of unsaturated soil mechanics to residual soils and mine waste and has published extensively in these areas. He has also applied unsaturated soil mechanics principles in related fields such as concrete and silo technology. He was a member of the International Society for Soil Mechanics and Foundation Engineering’s Technical Committee on the Properties of Tropical and Residual Soils from 1982 to 1997 and served as Chairman from 1994 to 1997. He edited and co-authored the first (1997) edition of "Mechanics of residual soils", which was produced during his Chairmanship. In addition to the second edition of Mechanics of residual soils (2012), he has also authored or co-authored the books: "Assessing loads on silos and other bulk storage structures" (2006), "Geotechnical engineering for mine waste storage facilities" (2010), "Alkali-aggregate reaction and structural damage to concrete" (2011), all published by CRC Press/Balkema.

Contenuti:

Preface
Acknowledgements
About the author
Scales, plotting conventions for graphs and reference lists
List of abbreviations and mathematical symbols

1 HISTORICAL REVIEW OF THE DEVELOPMENT OF UNSATURATED SOIL MECHANICS
1.1 Historical progress in unsaturated soil mechanics literature: Karl Terzaghi’s four books
1.2 Meetings, documents and books that were critical in establishing unsaturated soil mechanics as a sub-discipline of soil mechanics
1.2.1 Matrix suction
1.2.2 Solute (or osmotic) suction
1.3 Progress in disseminating knowledge of unsaturated soil mechanics via basic soil mechanics text books
1.4 The special problem of unsaturated soils
References
Plate

2 DETERMINING EFFECTIVE STRESSES IN UNSATURATED SOILS
2.1 The definition of an unsaturated soil
2.2 Interaction of pore air and pore water
2.3 The use of elevated pore-air pressures in the measurement of pore-water pressures (the axis translation technique) (Bishop & Blight, 1963)
2.4 The suction-water content curve (SWCC) (Blight, 2007)
2.4.1 Hysteresis in a saturated soil
2.4.2 Hysteresis in drying soils
2.4.3 Direct comparison between a consolidation curve and a SWCC
2.4.4 Hysteresis in compacted soils and the effect of particle size distribution
2.4.5 SWCCs extending to very dry soils, or high suctions
2.4.6 Empirical expressions for predicting SWCCs
2.4.7 The effect of soil variability on SWCCs and SWCCs measured by means of in situ tests
2.5 The characteristics of the effective stress equation for unsaturated soils (Bishop & Blight, 1963)
2.5.1 Evaluating the Bishop parameter χ or the Fredlund parameter ϕ b
2.5.2 Evaluating χ from the results of various types of shear
test, assuming that the equivalent test result for the saturated soil represents true effective stresses
2.5.3 Evaluating χ from compression, swelling and swelling pressure tests on the assumption that true effective stress behaviour of the unsaturated soil is represented by that of the same soil when saturated (Blight, 1965)
2.5.3.1 Isotropic compression
2.5.3.2 Isotropic swell
2.5.3.3 Swelling pressure
2.5.4 Summary of χ values from isotropic compression, swell and swelling pressure
2.5.5 The effect of stress path on values of χ
2.5.6 The χ parameter for compression of a collapsing sand
2.5.7 The parameter χ for extremely high values of suction
2.6 Incremental methods of establishing σ I and χ
2.6.1 Shear strength
2.6.2 Volume change
2.6.3 Summary
2.7 Empirical methods of estimating parameter χ
2.8 The limits of effective stress in dry soils (Blight, 2011)
2.8.1 The experiment
2.8.2 The conclusion
References
Appendix A2: Equation for the solution of a bubble in a compressible container
Plate

3 MEASURING AND CONTROLLING SUCTION
3.1 Direct or primary measurement of suction
3.1.1 Preparing the fine-pored ceramic
3.1.2 De-airing and testing fine-pored ceramic filters for air entry
3.1.3 The effects of capillarity on the de-airing process
3.1.4 Typical responses of tensiometers
3.1.5 Direct measurement of suctions exceeding 100 kPa
3.1.6 Null-flow methods of measuring suction
3.2 Indirect or secondary methods of measuring water content or suction
3.2.1 Filter paper
3.2.2 Thermal conductivity sensor
3.2.3 Electrical conductivity sensor
3.2.4 Time domain reflectometry (TDR)
3.2.5 Dielectric sensors
3.3 Thermodynamic methods of controlling or measuring suction
3.3.1 Control of relative humidity
3.3.2 Measuring relative humidity
3.3.2.1 Thermocouple psychrometer
3.3.2.2 Transistor psychrometer
3.3.2.3 Chilled-mirror psychrometer
3.4 A commentary on the use of the Kelvin equation as a measure of total suction
3.5 Use of direct and indirect suction measurements in the field
3.5.1 A comparison of field measurements of a suction profile using thermocouple psychrometers, contact and noncontact filter paper (van der Raadt, et al., 1987)
3.5.2 Near-surface changes of water content as a result of evapotranspiration (Blight, 2008)
3.5.3 A comparison of field measurements of suction by means of thermocouple psychrometers, gypsum blocks and glass fibre mats (Harrison & Blight, 2000)
3.5.4 Use of tensiometers to monitor the rate of infiltration of surface flooding into unsaturated soil strata (Indrawan, et al., 2006)
3.5.5 Use of suction gradients measured by gypsum blocks to examine the patterns of water flow in a stiff fissured clay (Blight, 2003)
3.5.6 Use of high tension tensiometers to monitor suctions in a test embankment (Mendes, et al., 2008)
3.5.7 Effect of covering the surface of a slope cut in residual granite soil with a capillary moisture barrier to stabilize the slope against surface sloughing (Rahardjo, et al., 2011) 132
3.6 A different application for measuring or controlling suction: Controlling alkali–aggregate reaction (AAR) in concrete, (Blight & Alexander, 2011)
3.6.1 Controlling alkali–aggregate reaction (AAR) in concrete
References
Plates

4 INTERACTIONS BETWEEN THE ATMOSPHERE AND THE EARTH’S SURFACE: CONSERVATIVE INTERACTIONS – INFILTRATION, EVAPORATION AND WATER STORAGE
4.1 The atmospheric water balance
4.2 The soil water balance
4.3 Measuring infiltration (I) and runoff (RO)
4.4 Estimating evapotranspiration by solar energy balance
4.5 Difficulties in applying the energy balance to estimating evaporation
4.5.1 Field experiments using a large cylindrical pan set into the ground surface (Blight, 2009a)
4.5.2 Field measurement of the water balance for a landfill
4.5.3 Evaporation from experimental landfill capping layers
4.5.4 Evaporation from a grassed, fissured clay surface (Clarens, South Africa)
4.5.5 Near-surface movement of water during evapotranspiration
4.5.6 Drying of tailings beaches deposited on tailings storage facilities
4.6 Fundamental mechanisms of evaporation from water and soil surfaces
4.6.1 Water or soil heat as sources and drivers of evaporation
4.6.2 The role of wind energy
4.7 Evaporation from unsaturated sand and the effect of vegetation – the efficiency factor η
4.8 Fundamental mechanisms of evaporation – discussion
4.9 Estimating evapotranspiration by means of lysimeter experiments
4.10 Depth of soil zone interacting with the atmosphere (also see section 4.5.5)
4.11 Recharge of water table and leachate flow from waste deposits
4.12 Estimating and measuring water storage capacity (S) for active zone
4.13 Seasonal and longer term variations in soil water balance
4.14 Consequences of a changing soil water balance
4.14.1 Effects on soil strength of a falling water table (also see section 8.8.1)
4.14.2 Effects of a rising water table – surface heave (also see section 8.6.2)
4.15 Cracking and fissuring of soil resulting from evaporation or evapotranspiration at the surface
4.15.1 Stresses in a shrinking soil
4.15.2 Cracking in a shrinking soil
4.15.3 Formation of shrinkage cracks at the surface
4.15.4 Formation of shrinkage cracks at depth
4.15.5 Characteristics of cracking observed in soil profiles
4.15.6 The formation of swelling fissures
4.15.7 Fissures in profiles that seasonally shrink and swell
4.15.8 Spacing of cracks on the surface
4.16 Damage to road pavements by upward migration of soluble salts
4.17 Root barriers to protect foundations of buildings from desiccating effects of tree roots (Blight, 2011)
4.17.1 Installation of root barriers
4.17.2 Effect of felling the tree
4.17.3 Examination of the exhumed root barriers
4.17.4 Conclusions
4.18 Use of an unsaturated soil layer to insulate flat (usually concrete) roofs (Gwiza, 2012)
4.19 Practical examples involving infiltration, evaporation and water storage
4.19.1 The infiltrate, store and evaporate (ISE) landfill cover layer (Blight & Fourie, 2005) (also see Fig. 4.11)
4.19.1.1 The influence of climate on landfilling practice
4.19.1.2 Dry tomb versus bioreactor
4.19.1.3 Water content of incoming waste
4.19.1.4 Stabilization in arid and semi-arid conditions
4.19.1.5 Evaporation from a landfill surface
4.19.1.6 Infiltrate-stabilize-evapotranspire (ISE) landfill covers
4.19.1.7 Field tests of ISE caps under summer and winter rainfall conditions
4.19.1.8 Rainfall infiltration and water storage
4.19.1.9 Concluding discussion
4.19.2 The effect of raising the height of a MSW landfill in a semi-arid climate
4.19.2.1 Introduction
4.19.2.2 Some effects of raising the height of a landfill
4.19.2.3 The measuring cells and their prior use
4.19.2.4 The experimental raising and its effect on settlement and leachate flow
4.19.2.5 Relationship between leachate quality and leachate flow rate
4.19.2.6 Compression characteristics of waste
4.19.2.7 Summary and conclusions
4.19.3 Interaction of pore air with steel reinforcing strips to cause accelerated corrosion in a reinforced compacted unsaturated soil structure
4.19.3.1 Introduction
4.19.3.2 Corrosion cause and progress
References
Appendix A4
A4.1 Calculating G, WH, H
A4.2 Calculating kT
A4.3 Conversion of volumetric water content wv to gravimetric water content wg
Plates

5 INTERACTIONS BETWEEN THE ATMOSPHERE AND THE EARTH’S SURFACE: DESTRUCTIVE INTERACTIONS – WATER AND WIND EROSION, PIPING EROSION
5.1 Factors controlling erosion from slopes
5.1.1 Results of early erosion measurements
5.1.2 Wind erosion compared with water erosion
5.1.3 Acceptable erosion rates for slopes
5.2 The mechanics of wind erosion
5.2.1 Variation of wind speed with height above ground level
5.2.2 Erosion and transportation by wind
5.3 Wind speed profiles over sand dunes and tailings storages
5.4 Wind tunnel tests on model waste storages
5.5 Wind flow over top surface of storage
5.6 Observed erosion and deposition by wind on full size waste storages
5.7 Protection of slopes against erosion by geotechnical means
5.7.1 Gravel mulching
5.7.2 Rock cladding
5.8 Full-scale field trials of rock cladding and rock armouring
5.9 Comments on wind and water erosion
5.10 Dispersive soils and piping erosion
5.11 Examples of piping erosion occurring in acid mine tailings
5.12 Other examples of failures by piping erosion
5.12.1 Failure of Teton dam (USA) (Seed & Duncan, 1981)
5.12.2 Gennaiyama and Goi dams (Japan) – failure by piping along outlet conduits (N’Gambi, et al., 1999)
5.12.3 Cut-off trench, Lesapi dam, Zimbabwe – stresses indicate piping unlikely (Blight, 1973)
5.12.4 Concrete spillway, Acton Valley dam, South Africa, piping along soil to concrete interfaces
5.12.5 Termite channels and piping flow
References
Plates

6 THE MECHANICS OF COMPACTION
6.1 The compaction process
6.2 Consequences of unsatisfactory compaction
6.3 Mechanisms of compaction
6.4 Laboratory compaction
6.5 Precautions to be taken with laboratory compaction
6.5.1 Moisture mixed into the soil not uniformly distributed
6.5.2 Soil aggregations or clods not broken down
6.5.3 Other treatments that affect laboratory compaction curve
6.6 Roller compaction in the field
6.7 Relationships between saturated permeability to water flow and optimum water content
6.8 Designing a compacted clay layer for permeability
6.9 Seepage through field-compacted layers
6.10 Control of compaction in the field
6.10.1 In situ dry density
6.10.2 In situ water content
6.10.3 In situ dry density within a range of water contents
6.10.4 In situ strength
6.10.5 In situ permeability
6.10.6 Laboratory strength properties correlated to in situ measurements
6.10.7 Recipe specifications
6.11 Special considerations for work in climates with large rates of evaporation
6.12 Additional points for consideration
6.12.1 Variability of borrow material
6.12.2 Compactor performance
6.12.3 Testing frequency
6.13 Compaction of residual soils
6.14 Mechanics of unsaturated compacted soils during and after construction
6.15 Pore air pressures caused by undrained compression of compacted soil
6.16 Use of compaction to improve foundation conditions
6.17 Settlement of an earth embankment constructed of compacted residual soil (Blight, et al., 1980)
6.18 Summary
References
Appendix A6: Development of Hilf’s equation in mass terms
Plate

7 STEADY AND UNSTEADY FLOW OF WATER AND AIR THROUGH SOILS – PERMEABILITY OF UNSATURATED AND SATURATED SOILS
7.1 Darcy’s and Fick’s laws of steady-state seepage flow
7.2 Displacement of water from soil by air
7.3 Unsteady flow of air through partly saturated and dry soils
7.4 Unsteady flow of air through dry rigid and compressible soils
7.5 Unsteady flow of air through unsaturated soil
7.6 Measuring permeability to water flow in the laboratory
7.7 Observed differences between small scale and large scale permeability measurements
7.8 Laboratory tests for permeability to water flow
7.9 Measuring permeability to air flow
7.10 Water permeability of unsaturated soils
7.11 Methods for measuring water permeability in situ
7.11.1 Permeability from surface ponding or infiltration tests
7.11.2 Permeability from borehole inflow or outflow
7.11.2.1 Variable head tests
7.11.2.2 Constant head tests
7.11.2.3 Determination of the steady state condition
7.11.2.4 Determination of the effective head at test zone, Hc
7.12 Estimation of permeability from large-scale field tests
7.12.1 Tests for rough estimates of permeability
7.12.2 Matsuo, et al.’s method
7.12.3 Extension of Matsuo, et al.’s method
7.12.3.1 Seepage pits
7.12.3.2 Calibration of measured water levels
7.12.3.3 Measurement of seepage into clay
7.12.3.4 Seepage into tailings
7.12.3.5 Analysis of permeability and results
7.13 Large-scale permeability tests using a test pad
7.14 Permeability characteristics of residual soils
7.15 Practical application of theory of consolidation of dry powders  to design of cement factory silos (Blight, 1971, 1982 & 2002)
7.15.1 Introduction
7.15.2 Calculation of variation of ua with time after start of loading
7.15.3 Use of theory in silo design
7.16 Practical application of injection of air into unsaturated tailings deposit to effect in situ solubilization of uranium in solution mining (Blight, 1973)
7.16.1 Field sites and installations
7.16.2 Pressure profiles for steady-state injection of air into single wells
7.16.3 Pressure profiles for unsteady injection of air into a single well
7.16.4 Additive effect of adjacent injection wells
7.16.5 Pressure contours for steady-state air injection into a single well
7.17 Solubilization achieved by aeration
References
Appendix A7: Methods of calculating permeabilities
A7.1 Hvorslev’s method
A7.2 Calculating kv and kh from seepage data for paired pits of differe...

Su questa edizione

• Editore: CRC Press
• Data di pubblicazione: 2013
• ISBN 10: 0415621186
• ISBN 13: 9780415621182
• Rilegatura: Copertina rigida
• Numero edizione: 1
• Numero di pagine: 640