Soil Mechanics and Foundation Engineering

Cover
Contents
Preface
Chapter 1: Soil Formation and Composition
	Chapter Highlights
	1.1 Introduction
	1.2 Origin of Soils
	1.3 Types of Weathering
		1.3.1 Physical Weathering
		1.3.2 Chemical Weathering
	1.4 Soil Formation
		1.4.1 Residual Soils
		1.4.2 Transported Soils
		1.4.3 Desiccated Soils
	1.5 Major Soil Deposits of India
		1.5.1 Marine Deposits
		1.5.2 Black Cotton Soils
		1.5.3 Laterites and Lateritic Soils
		1.5.4 Alluvial Deposits
		1.5.5 Desert Soils
	1.6 Components of Soils
		1.6.1 Solid Phase
		1.6.2 Liquid Phase
		1.6.3 Gaseous Phase
	1.7 Particle Sizes and Shapes
		1.7.1 Particle Size
		1.7.2 Particle Shape
	1.8 Inter-Particle Forces
	1.9 Soil Minerals
		1.9.1 Clay Minerals
		1.9.2 Framework Silicate Minerals
	1.10 Soil–Water System
	1.11 Physico-Chemical Behaviour of Clays
		1.11.1 Characteristics of Electrolytes
		1.11.2 Electrochemical Characteristics
		1.11.3 Characteristics of Bacteria
		1.11.4 Electrokinetic Phenomena
		1.11.5 Characteristics of Heat
	1.12 Soil Structure
		1.12.1 Structure of Granular Soils
		1.12.2 Structure of Cohesive Soils
	Points to Remember
	Questions
Chapter 2: Index Properties of Soils
	Chapter Highlights
	2.1 Introduction
	2.2 Three-Phase System
		2.2.1 Void Ratio (e)
		2.2.2 Porosity (n)
		2.2.3 Degree of Saturation (Sr)
		2.2.4 Air Void Ratio (Av) or Air Content
		2.2.5 Specific Gravity of Soil Solids (G)
		2.2.6 Water Content (w) or Moisture Content
		2.2.7 Soil Densities
		2.2.8 Unit Weights
		2.2.9 Density Index (ID)
	2.3 Particle-Size Analysis
		2.3.1 Sieve Analysis
		2.3.2 Sedimentation Analysis
		2.3.3 Grain-Size Distribution Curves
	2.4 Consistency of Soils
		2.4.1 Atterberg Limits
		2.4.2 Activity of Clays
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 3: Identification and Classification of Soils
	Chapter Highlights
	3.1 Introduction
	3.2 Field Identification of Soils
		3.2.1 Coarse-grained soils
		3.2.2 Fine-grained soils
	3.3 Engineering Classification of Soils
		3.3.1 Purpose of Classification Systems
		3.3.2 Unified Soil Classification System
		3.3.3 Indian Soil Classification System
		3.3.4 AASHTO Soil Classification System
		3.3.5 Textural Soil Classification System
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 4: Compaction of Soils
	Chapter Highlights
	4.1 Introduction
	4.2 Principles of Compaction
	4.3 Compactive Effort
	4.4 Laboratory Compaction
		4.4.1 Standard Proctor Test
		4.4.2 Modified Proctor Test
		4.4.3 Indian Standard Compaction Tests
	4.5 Field Compaction and Equipment
	4.6 Compaction Specification and Control
		4.6.1 Specification
		4.6.2 Field Control
	4.7 Factors Affecting Compaction
		4.7.1 Effect of Moisture Content
		4.7.2 Effect of Compactive Effort
		4.7.3 Effect of Type of Soil
		4.7.4 Effect of Method of Compaction
	4.8 Effect of Compaction on Soil Structure
	4.9 Compaction Behaviour of Sand
	4.10 California Bearing Ratio Test
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 5: Permeability and Capillarity
	Chapter Highlights
	5.1 Introduction
	5.2 Water Flow
	5.3 Darcy’s Law
	5.4 Range of Validity of Darcian Flow
	5.5 Laboratory Permeability Tests
		5.5.1 Constant Head Permeameter
		5.5.2 Falling Head Permeameter
	5.6 Field Permeability Tests
		5.6.1 Unconfined Flow Pumping Out Test
		5.6.2 Confined Flow Pumping Out Test
	5.7 Permeability of Stratified Soils
		5.7.1 Horizontal Flow
		5.7.2 Vertical Flow
	5.8 Values of Permeability
	5.9 Factors Affecting Permeability
		5.9.1 Soil Characteristics
		5.9.2 Pore Fluid Characteristics
	5.10 Surface Tension
	5.11 Capillary Phenomenon in Soils
	5.12 Shrinkage and Swelling of Soils
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 6: Seepage
	Chapter Highlights
	6.1 Introduction
	6.2 Seepage Forces
	6.3 General Flow Equation
	6.4 Significance of Laplace’s Equation
	6.5 Properties and Applications of Flow Nets
		6.5.1 Properties
		6.5.2 Applications
	6.6 Construction of Flow Net
		6.6.1 Boundary Conditions
		6.6.2 Construction Methods
	6.7 Anisotropic Soil Conditions
	6.8 Non-Homogeneous Soil Conditions
	6.9 Piping
	6.10 Design of Filters
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 7: Stress and Stress Distribution in Soil
	Chapter Highlights
	7.1 Introduction
	7.2 Stresses at a Point
	7.3 Mohr’s Circle
	7.4 Stress Paths
	7.5 Effective Stress Concept
		7.5.1 Dry Soil
		7.5.2 Saturated Soil
		7.5.3 Partially Saturated Soil
	7.6 Geostatic Stresses
		7.6.1 Case 1 – Soil Entirely Dry
		7.6.2 Case 2 – Moist Soil
		7.6.3 Case 3 – Completely Submerged Soil with Water Table at Ground Surface
		7.6.4 Case 4 – Completely Saturated by Capacity Action Above Water Table But No Flow
		7.6.5 Case 5 – Same as Condition 4 Except that the Height of Capillary Rise Is Less than z
	7.7 Stresses Due to Surface Loads
		7.7.1 Elastic Half-Space
		7.7.2 Elastic Properties of Soil
		7.7.3 Boussinesq’s Theory
		7.7.4 Pressure Distribution Diagrams
		7.7.5 Westergaard Equation
		7.7.6 Types of Surface Loads
		7.7.7 Contact Pressure
		7.7.8 Validity of Elastic Theory Application
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 8: Consolidation and Consolidation Settlement
	Chapter Highlights
	8.1 Introduction
	8.2 Rheological Models of Soils
	8.3 Compressibility of Soils
	8.4 One-Dimensional Consolidation
	8.5 Consolidation test
	8.6 Compressibility Characteristics
		8.6.1 Pressure–Void Ratio Curves
		8.6.2 Compression Index
		8.6.3 Coefficient of Compressibility
		8.6.4 Coefficient of Volume Compressibility
		8.6.5 Degree of Consolidation
	8.7 Types of Clay Deposits
		8.7.1 Normally Consolidated Clay
		8.7.2 Over-consolidated Clay
		8.7.3 Under-consolidated Clay
	8.8 Prediction of Pre-Consolidated Pressure
	8.9 Rate of Consolidation
		8.9.1 Terzaghi’s Theory of One-Dimensional Consolidation
		8.9.2 Time Factor
		8.9.3 Determination of Coefficient of Consolidation
	8.10 Secondary Compression
	8.11 Consolidation Settlement and its Rates
		8.11.1 Consolidation Settlement
		8.11.2 Construction Period Correction
		8.11.3 Settlement Due to Secondary Compression
		8.11.4 Predicting the Rate of Settlement
	8.12 Acceleration of Consolidation by Sand Drains
	8.13 Compressibility of Sands
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 9: Shear Strength of Soils
	Chapter Highlights
	9.1 Introduction
	9.2 Stress–Strain Curve
	9.3 Mohr–Coulomb Failure Criterion
	9.4 Peak and Residual Shear Strengths
	9.5 Laboratory Measurement of Shear Strength
		9.5.1 Drainage Condition
		9.5.2 Shear- and Strain-Controlled Tests
		9.5.3 Direct Shear Test
		9.5.4 Reversal Direct Shear Test
		9.5.5 Triaxial Shear Test
		9.5.6 Unconfined Compression Test
		9.5.7 Ring Shear Test
		9.5.8 Choice of Rate of Deformation
	9.6 Field Measurement of Shear Strength
		9.6.1 Vane Shear Test
		9.6.2 Borehole Shear Device
	9.7 Shear Strength of Saturated Cohesive Soils
		9.7.1 Undrained Strength
		9.7.2 Consolidated–Undrained Strength
		9.7.3 Strength in Terms of Effective Stresses
	9.8 Pore Pressure Coefficients
		9.8.1 Theory
		9.8.2 Measurement of Pore Pressure Coefficients
		9.8.3 Application of Pore Pressure Coefficients
	9.9 Sensitivity of Cohesive Soils
	9.10 Thixotrophy of Clays
	9.11 Shear Strength of Granular Soils
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 10: Laboratory Measurement of Soil Properties
	Chapter Highlights
	10.1 Introduction
	10.2 Test No. 1: Preparation of Dry Soil Samples for Various Tests
	10.3 Test No. 2: Specific Gravity of Soil Solids
	10.4 Test No. 3: Water Content Determination by Oven-Drying Method
	10.5 Test No. 4: In-Place Dry Density of Soil by Core-Cutter Method
	10.6 Test No. 5: In-Place Dry Density of Soil by the Sand Replacement Method
	10.7 Test No. 6: Grain-Size Distribution by Sieve Analysis
	10.8 Test No. 7: Grain-Size Distribution by Pipette Method
	10.9 Test No. 8: Grain-Size Distribution by the Hydrometer Method
	10.10 Test No. 9: Liquid Limit of Soil
	10.11 Test No. 10: Plastic Limit of Soil
	10.12 Test No. 11: Shrinkage Factors of Soil
	10.13 Test No. 12: Linear Shrinkage of Soil
	10.14 Test No. 13: Permeability Test
	10.15 Test No. 14: Free Swell Index of Soils
	10.16 Test No. 15: Moisture Content – Dry Density Relationship (Standard Proctor Compaction Test)
	10.17 Test No. 16: Density Index of Non-Cohesive Soils
	10.18 Test No. 17: Consolidation Test
	10.19 Test No. 18: Unconfined Compression Test
	10.20 Test No. 19: Direct Shear Test
	10.21 Test No. 20: Triaxial Shear Test
	10.22 Test No. 21: California Bearing Ratio (CBR) Test
	Points to Remember
	Questions
Chapter 11: Lateral Earth Pressure
	Chapter Highlights
	11.1 Introduction
	11.2 Limit Analysis and Limit Equilibrium Methods
	11.3 Earth Pressure at Rest
	11.4 Rankine’s States of Plastic Equilibrium
	11.5 Rankine’s Earth Pressure Theory
		11.5.1 Effect of Level Backfill Surface
		11.5.2 Effect of Surcharge Load on Backfill Surface
		11.5.3 Effect of Water Table on a Backfill
		11.5.4 Effect of Stratified Soils in the Backfill
		11.5.5 Effect of c–φ Soils as Backfill
	11.6 Coulomb’s Earth Pressure Theory
	11.7 Culmann’s Graphical Method
	11.8 Poncelet’s Graphical Method
	11.9 Arching of Soils
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 12: Earth-Retaining Structures
	Chapter Highlights
	12.1 Introduction
	12.2 Gravity-Type Retaining Walls
		12.2.1 Proportioning Retaining Walls
		12.2.2 Earth Pressure Consideration
		12.2.3 Stability Requirements
		12.2.4 Backfill Materials and Drainage
		12.2.5 Joints in Retaining Walls
	12.3 Sheet Pile Walls
		12.3.1 Cantilever Sheet Pile Walls
		12.3.2 Anchored Sheet Pile Walls
		12.3.3 Wales, Tie rods, and Anchorages for Sheet Piling
	12.4 Braced Excavations
		12.4.1 Earth Pressure Distribution
		12.4.2 Failure of Braced Cuts
		12.4.3 Heave of the Bottom of a Clay Cut
		12.4.4 Stability of the Bottom of the Cut in Sand
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 13: Stability of Slopes
	Chapter Highlights
	13.1 Introduction
	13.2 Causes of Slope Failures
	13.3 Short- and Long-Term Failures
	13.4 Types of Landslides and Slope Movements
		13.4.1 Basic Types of Landslides
		13.4.2 Multiple and Complex Slides
		13.4.3 Rates of Land Movement
	13.5 Factor of Safety
	13.6 Basic Concepts of Slope Stability Analysis
	13.7 Infinite and Finite Slopes
	13.8 Analysis of Infinite Slopes
		13.8.1 Infinite Dry or Moist Cohesive Slope
		13.8.2 Infinite Cohesive Slopes with Seepage
		13.8.3 Infinite Non-cohesive Slopes with Seepage
		13.8.4 Infinite Dry or Moist Non-cohesive Slope
	13.9 Analysis of Finite Slopes
		13.9.1 Planar Failure Surface
		13.9.2 Circular Failure Surfaces
		13.9.3 Non-circular Failure Surfaces
	13.10 Selection of Shear Strength Parameters and Stability Analysis
	13.11 Slope Protection Measures
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 14: Bearing Capacity of Soils
	Chapter Highlights
	14.1 Introduction
	14.2 Bearing Capacity
		14.2.1 Bearing Capacity Criteria
		14.2.2 Factors Affecting Bearing Capacity
	14.3 Modes of Shear Failure
		14.3.1 General Shear Failure
		14.3.2 Local Shear Failure
		14.3.3 Punching Shear Failure
	14.4 Terzaghi’s Bearing Capacity Theory
	14.5 Foundation Pressures
	14.6 Special Loading and Ground Conditions
		14.6.1 Foundations with Eccentric Loading
		14.6.2 Foundation Subjected to Inclined Load
		14.6.3 Foundations on Sloping Surface
		14.6.4 Foundations on Stratified Soil
		14.6.5 Foundations on Partially Saturated Soil
		14.6.6 Foundations on Desiccated Soil
		14.6.7 Foundations on Rock
	14.7 Other Bearing Capacity Theories
		14.7.1 Modified Bearing Capacity Formulae (IS: 6403, 1981)
		14.7.2 Skempton’s Bearing Capacity Theory
		14.7.3 Meyerhof’s Bearing Capacity Theory
		14.7.4 Brinch Hansen’s Bearing Capacity Theory
	14.8 Bearing Capacity of Soils from Building Code
	14.9 Permissible Settlements
	14.10 Allowable Bearing Pressure
	14.11 Estimation of Bearing Capacity from Field Tests
		14.11.1 Bearing Capacity Based on Standard Penetration Test
		14.11.2 Bearing Capacity Based on Cone Penetration Test
		14.11.3 Bearing Capacity Based on Plate Load Test
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 15: Shallow Foundations
	Chapter Highlights
	15.1 Introduction
	15.2 Design Criteria
	15.3 Types of Shallow Foundations
		15.3.1 Spread Footings
		15.3.2 Combined Footings
		15.3.3 Continuous Footings
		15.3.4 Mat Foundations or Footings
		15.3.5 Floating Foundations
	15.4 Selection of the Type of Foundation
	15.5 Location and Depth of the Foundation
		15.5.1 Volume Change of Soil
		15.5.2 Adjacent Structures
		15.5.3 Groundwater
		15.5.4 Underground Defects
	15.6 Causes of Settlement
	15.7 Settlement of Shallow Foundations
		15.7.1 Immediate Settlement
		15.7.2 Consolidation Settlement
		15.7.3 Evaluation of Settlement from Field Tests
		15.7.4 Reliability of Settlement Computations
	15.8 Design Steps for a Shallow Foundation
	15.9 Proportionating Footing Size
	15.10 Design of Combined Footings
		15.10.1 Rectangular Combined Footing
		15.10.2 Trapezoidal Combined Footing
		15.10.3 Combined Strap Footing
	15.11 Mat Foundation
		15.11.1 Types of Mat Foundations
		15.11.2 Bearing Capacity of Mat Foundations
		15.11.3 Design Methods
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 16: Pile Foundations
	Chapter Highlights
	16.1 Introduction
	16.2 Classification of Piles
		16.2.1 Material Composition
		16.2.2 Installation Methods
		16.2.3 Ground Effects
		16.2.4 Function as Foundation
	16.3 Pile-Driving Equipment
	16.4 Bearing Capacity of Single Pile
		16.4.1 Pile Capacity from Statical Methods for Driven Piles
		16.4.2 Pile Capacity from Statical Methods for Cast In Situ or Bored Piles
		16.4.3 Pile Capacity from Pile-Driving Formulae
		16.4.4 Pile Capacity from Wave Equation
		16.4.5 Pile Capacity Based on SPT Values on Non-Cohesive Soils
		16.4.6 Pile Capacity from Pile Load Test
		16.4.7 Negative Skin Friction
	16.5 Under-Reamed Piles
	16.6 Pile Groups
		16.6.1 Pile Group Capacity
		16.6.2 Pile Group in Filled Ground
		16.6.3 Pile Group Settlement
	16.7 Uplift Resistance of Piles
		16.7.1 Uplift of Single Piles
		16.7.2 Uplift of Pile Groups
	16.8 Lateral Resistance of Piles
	16.9 Inclined Loading of Vertical Piles
	16.10 Pile Cap
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 17: Drilled Piers and Caisson Foundations
	Chapter Highlights
	17.1 Introduction
	17.2 Drilled Piers
		17.2.1 Uses
		17.2.2 Types of Drilled Piers
		17.2.3 Bearing Capacity of Drilled Piers
		17.2.4 Settlement of Drilled Piers
		17.2.5 Construction Procedures of Drilled Piers
	17.3 Caissons
		17.3.1 Uses
		17.3.2 Types of Caissons
		17.3.3 Bearing Capacity and Settlement of Caissons
		17.3.4 Construction Procedure of Caissons
	17.4 Well Foundations
		17.4.1 Types of Wells
		17.4.2 Components of Well Foundations
		17.4.3 Design of Wells
		17.4.4 Stability Analysis of Well Foundations (Approximate Solution)
		17.4.5 Stability Analysis of a Heavy Well
		17.4.6 Construction of Well Foundations
		17.4.7 Shifts and Tilts
	Points to Remember
	Questions
	Exercise Problems
Chapter 18: Ground Investigation
	Chapter Highlights
	18.1 Introduction
	18.2 Planning the Ground Investigation Programme
	18.3 Types of Soil and Rock Samples
	18.4 Indirect Methods of Sub-Surface Exploration
		18.4.1 Geophysical Methods
		18.4.2 Sounding Methods
	18.5 Semi-Direct Methods of Sub-Surface Exploration
		18.5.1 Wash Boring
		18.5.2 Rotary Drilling
		18.5.3 Auger Boring
	18.6 Direct Methods of Sub-Surface Exploration
		18.6.1 Sampling Process
		18.6.2 Sample Disturbance
		18.6.3 Types of Samplers
		18.6.4 Accessible Explorations
		18.6.5 Undisturbed Sampling of Soils
	18.7 Routine Field Tests
		18.7.1 Standard Penetration Test (SPT)
		18.7.2 Cone Penetration Test (CPT)
		18.7.3 Vane Shear Test
		18.7.4 Groundwater Observations
	18.8 Recording of Field Data
	18.9 Location, Spacing, and Depth of Borings
	Points to Remember
	Questions
	Exercise Problems
Chapter 19: Soil Improvement
	Chapter Highlights
	19.1 Introduction
	19.2 Improvement Techniques
	19.3 Surface Compaction
	19.4 Drainage Methods
		19.4.1 Well-Point Systems
		19.4.2 Deep-Well Drainage
		19.4.3 Vacuum De-watering System
		19.4.4 De-watering by Electro-osmosis
	19.5 Vibration Methods
		19.5.1 Vibro-Compaction
		19.5.2 Vibro-Displacement Compaction
	19.6 Pre-Compression and Consolidation
		19.6.1 Pre-loading and Surcharge Fills
		19.6.2 Vertical Drains
		19.6.3 Dynamic Consolidation
		19.6.4 Electro-osmotic Consolidation
	19.7 Grouting and Injection
		19.7.1 Suspension Grouts
		19.7.2 Solution Grouts
	19.8 Chemical Stabilization
		19.8.1 Lime Stabilization
		19.8.2 Cement Stabilization
		19.8.3 Fly Ash Stabilization
	19.9 Soil Reinforcement
	19.10 Geotextiles and Geomembranes
		19.10.1 Geotextiles
		19.10.2 Geomembranes
	19.11 Other Methods
		19.11.1 Thermal Methods
		19.11.2 Moisture Barriers
		19.11.3 Pre-wetting
		19.11.4 Addition or Removal
	Points to Remember
	Questions
	Exercise Problems
Chapter 20: Embankment Dams
	Chapter Highlights
	20.1 Introduction
	20.2 Types of Embankment Dams
		20.2.1 Diaphragm Type
		20.2.2 Homogeneous Type
		20.2.3 Zoned Type
	20.3 Components of Embankment Dams
		20.3.1 Foundation
		20.3.2 Casing
		20.3.3 Core
		20.3.4 Other Embankment Details
	20.4 Design Criteria for Earth Dams
		20.4.1 Safety Against Over-Topping
		20.4.2 Control of Seepage and Pressure in Earth Dams
		20.4.3 Protection Against Free Passage of Water Through Dams
		20.4.4 Stability of Earth Dam Slopes
		20.4.5 Protection of Crest, Upstream, and Downstream Faces
	20.5 Selection of Dam Section
		20.5.1 Earth Dam
		20.5.2 Rockfill Dams
	Worked Examples
	Points to Remember
	Questions
	Exercise Problems
Chapter 21: Dynamic Loading of Soil
	Chapter Highlights
	21.1 Introduction
	21.2 Earthquakes
		21.2.1 Seismic Waves
		21.2.2 Magnitude
	21.3 Other Dynamic Loads
	21.4 Theory of Vibrations
		21.4.1 Harmonic Vibrations
		21.4.2 Free Vibration of a Spring–mass System
		21.4.3 Free Vibration with Viscous Damping
		21.4.4 Forced Vibrations with Viscous Damping
	21.5 Types of Machines and Machine Foundations
	21.6 Dynamic Bearing Capacity of Shallow Foundations
	21.7 Design Requirements
	21.8 Methods of Analysis for Block Foundation
	21.9 Liquefaction of Soils
	Points to Remember
	Questions
Chapter 22: Environmental Geotechnology
	Chapter Highlights
	22.1 Introduction
	22.2 Environmental Cycles
	22.3 Natural Cycles
		22.3.1 Oxygen Cycle
		22.3.2 Nitrogen Cycle
		22.3.3 Carbon Cycle
	22.4 Environmental Imbalance
		22.4.1 Solid and Liquid Wastes
		22.4.2 Petroleum Contamination
		22.4.3 Acid Rain and Acid Drainage
		22.4.4 Scrap Wastes
		22.4.5 Arid Lands and Deserts
		22.4.6 Wetlands
		22.4.7 Coastal Margins
		22.4.8 Soil Erosion
		22.4.9 Land Subsidence
	22.5 Birth of Environmental Geotechnology
	22.6 Contaminated Soils
		22.6.1 Identification
		22.6.2 Classification
		22.6.3 Permeability
		22.6.4 Electrical Properties
		22.6.5 Shear Strength
		22.6.6 Consolidation
	22.7 Applications
	22.8 Load–Environment Design Criteria
	Points to Remember
	Questions
Chapter 23: Introductory Rock Mechanics
	Chapter Highlights
	23.1 Introduction
	23.2 Index Properties of Rocks
		23.2.1 Porosity
		23.2.2 Density
		23.2.3 Permeability
		23.2.4 Strength
		23.2.5 Slaking and Durability
		23.2.6 Sonic Velocity
	23.3 Classification of Rocks
	23.4 In Situ State of Stress
		23.4.1 Vertical Stress
		23.4.2 Horizontal Stress
		23.4.3 Effective Stress in Rock Masses
		23.4.4 Measurement of In Situ Stresses
	23.5 Mechanical Properties of Rocks
		23.5.1 Modes of Failure of Rock
		23.5.2 Behaviour of Rocks in Uniaxial Compression
		23.5.3 Tensile Strength of Rocks
		23.5.4 Behaviour of Rocks in Triaxial Compression
		23.5.5 Failure Theory Applicable to Rocks
		23.5.6 Shear Strength of Rocks
		23.5.7 Elastic Properties of Rocks
		23.5.8 Hardness
	Points to Remember
	Questions
	Exercise Problems
List of Symbols
Bibliography
Index