Ground improvement techniques
Purushothamaraj, P.
Ground improvement techniques - New Delhi University Science Press 2011 - xvi,265p.
CONTENTS 1. Formation and Development of Ground 1 1.1 Introduction 1 1.2 Formation of Rock, Soil and Soil Profile 1 1.2.1 Principal Rock Types 1 1.2.2 Origin of Soils 3 1.2.3 Types of Weathering 3 1.2.4 Major Soil Types 4 1.2.5 Soil Profile 7 1.3 Soil Distribution in India 9 1.3.1 Marine Deposits 9 1.3.2 Black Cotton Soils 9 1.3.3 Laterites and Lateritic Soils and Murrums 10 1.3.4 Alluvial Deposits 11 1.3.5 Desert Soils 12 1.3.6 Boulder Deposits 12 1.4 Alterations of Ground After Formation 12 1.4.1 Effect of Seasonal Moisture Variation 12 1.4.2 Effect of Water Seepage and Surface Erosion 14 1.4.3 Effect of Vegetation 14 1.4.4 Effect of Temperature Variation 14 1.4.5 Effect of Vibration 15 1.4.6 Effect of Mining Subsidence and Pumping 15 1.4.7 Effect of Construction Operation 16 1.5 Reclaimed Soils 17 1.5.1 Types of Reclamation Materials 17 1.5.2 Construction Methods 18 1.5.3 Landfill Gas and Leachate 22 115.4 Landfill Liners and Caps 23 1.6 Ground Improvement Potentia 24 1.6.1 Hazardous Ground Conditions 24 1.6.2 Poor Ground Conditions 25 1.6.3 Favourable Ground Conditions 25 1.6.4 Alternative Approaches 26 1.6.5 Geotechnical Processes 26 2. Compaction 28 2.1 Introduction .. 28 2.2 Compaction Mechanics 28 2.2.1 Densification 28 2.2.2 Moisture-Density Relationship 29 2.2.3 Laboratory Compaction Tests 31 2.2.4 Compactive Effort 32 2.2.5 Engineering Behaviour of Compacted Fine-grained Soils 33 2.3 Field Procedure 34 2.3.1 Controlled Compacted FiU 35 2.3.2 Pavement Subgrade 35 2.3.3 Material Selection Factors 35 2.3.4 Borrow Pits 36 2.3.5 Placement and Processing 37 2.3.6 Compaction Specification 37 2.4 Surface Compaction 37 2.4.1 Smooth-Wheel Rollers 38 2.4.2 Sheepsfoot Rollers 38 2.4.3 Grid Rollers 39 2.4.4 Pneumatic-Tired Rollers 39 2.4.5 Other Surface Compaction Devices 41 2.4.6 Dynamic Compaction 42 2.5 Selection of Field Compaction Procedures 43 2.5.1 Choice of Equipment 43 2.5.2 Layer Thickness 44 2.5.3 Wetting and Drying Methods 44 2.5.4 Construction Traffic 44 2.5.5 Selection of Soil and Degree of Compaction 44 2.5.6 Trial Embankments 44 2.6 Compaction Quality Control 45 2.6.1 Moisture Content Measurements 46 2.6.2 In-situ Density Measurements 46 2.6.3 Nuclear Moisture-Density Method 47 2.6.4 Hill's Method 47 3. Drainage Methods 48 3.1 Introduction 48 3.2 Seepage 48 3.3 Filter Requirements 50 3.4 Groundwater 51 3.5 Groundwater and Seepage Control 52 3.6 Methods of Dewatering Systems 53 3.6.1 Open Sumps and Ditches 54 3.6.2 Wellpoint Systems 54 3.6.3 Deep-well Drainage 59 3.6.4 Vacuum Dewatering Systems 60 3.6.5 Dewatering by Electro-osmosis 61 3.7. Design Steps for Dewatering Systems 68 3.7.1 Subsoil Investigation 68 3.7.2 Source and Water Table Details 68 3.7.3 Distance of Wellpoints/Wells from Source of Seepage 70 3.7.4 Effective Well Radius 70 3.7.5 Discharge Computations 70 3.7.6 Design of Filters .. 76 3.7.7 Design and Selection of Well Screens 76 3.7.8 Selection of Pumps and Accessories 76 3.7.9 Wellpointing in Deep Excavations 77 3.7.10 Deep Bored Wells 77 3.7.11 Control of Surface Water 78 3.8. Drains 78 3.8.1 Open Drains 79 3.8.2 Closed Drains 79 3.8.3 Horizontal Drains 79 3.8.4. Drainage After Construction 79 4. Preeompression and Vertical Drains 82 4.1 Introduction 82 4.2 Compressibility of Soils and Consolidation82 4.2.1. Compressibility 82 4.2.2 One-dimensional Consolidation 84 4.2.3 Compressibility Characteristics of Soil Deposits 85 4.2.4 Methods of Evaluating Compressibility 88 4.2.5 Rate of Consolidation 91 4.2.6 Accelerating-Consolidation 93 4.3 Preloading and Surcharge Fills 94 4.3.1 Precompression Principles 94 4.3.2 Preloading Methods 95 4.3.3 Construction Requirements 98 4.4 Monitoring of Compression 99 4-4.1 Predictions from Borings and Tests 100 4.4.2 Prediction from Test Fills 102 4.4.3 Monitoring Time Rate of Settlement 102 4.4.4 Instrumentation 103 4.5 Vertical Drains 104 4.5.1 General Principle 104 4.5.2 Design of Vertical Drains 106 4.5.3 Types and Construction of Vertical Drains 110 4.5.4 Efficiency of Vertical Drains 113 4.5.5 Applications 114 4.6 Dynamic Consolidation 117 4.7 Consolidation by Electro-osmosis 118 5. Vibratipn Methods 124 5.1Introduction 124 5.2 Vibro-Compaction 124 5.2.1 Blasting 125 5.2.2 Vibratory Probe 127 5.2.3. Vibratory Compactors 128 5.3 Vibro-Displacement Compaction 129 5.3.1 Displacement Piles 130 5.3.2 Vibroflotation 130 5.3.3 Sand Compaction Piles 138 5.3.4 Stone Columns 140 5.3.5 Heavy Tamping 145 6. Grouting and Injection 146 6.1 Introduction 146 6.2 Aspects of Grouting 147 6.2.1 Groutability 148 6.2.2 Grouting Materials 149 6.2.3 Suspension Grouts 149 6.2.4 Solution Grouts 152 6.2.5 Compaction Grouting 156 6.3 Grouting Procedure 157 6.3.1 Pre-grouting Site Investigation 157 6.3.2 Grout Holes Pattern158 6.3.3 Grout Characteristics 159 6.3.4 Grouting Plant and Equipmen 160 6.3.5 Injection Methods 163 6.3.6 Grout Injection Measurements and Monitoring 170 6.4 Applications 171 6.4.1 Seepage Control 171 6.4.2 Soil Solidification and Stabilization 174 6.4.3 Vibration Control 175 7. Mechanical, Cementing and Chemical Stabilization 177 7.1 Introduction 177 7.2 Requirements of Soil Stabilization 177 7.3 Mechanical Stabilization 178 7.3.1 Mechanical Stability of Materials 178 7.3.2 Proportioning the Materials 179 7.3.3 Addition or Removal of Soil Particles 180 7.4. Portland Cement (Cementing) Stabilization 180 7.4.1 Nature of Soil 181 7.4.2 Amount of Cement 181 7.4.3 Mixing 183 7.4.4 Moisture Content 183 7.4.5 Compaction Conditions 184 7.4.6 Age and Curing 185 7.4.7 Admixtures for Soil-Cement 185 7.4.8 Construction of Soil-Cement 185 7:5 Bituminous (Cementing) Stabilization 186 7.5.1 Nature of Soil 186 7.5.2 Amount of Asphalt 187 7.5.3 Mixing 187 7.5.4 Compaction Conditions 188 7.5.5 Cure Conditions 188 7.5.6 Construction of Soil-Asphalt 189 7.6 Chemical Stabilization 189 7.6.1 Lime 189 7.6.2 Calcium and Sodium Chlorides 190 7.6.3 Lignin 190 7.6.4 Waterproofers 191 7.6.5 Natural and Synthetic Polymers 191 7.6.6 Aggregants and Dispersants 192 7.6.7 Miscellaneous Chemical Stabilizers 194 7.7 Construction Methods 194 7.7.1 Mix-in-place Method 194 7.7.2 Travelling Plant Method 195 7.7.3 Stationary Plant Method 195 7.7.4. Field Control 196 8. Geosynthetics 199 8.1 Introduction 199 8.2 Geosynthetic Types 199 8.2.1 Raw Materials 200 8.2.2 Wovens 201 8.2.3 Non-wovens 201 8.2.4 Knitted 204 8.2.5 Biogradable 204 8.2.6 Nets and Grids 204 8.2.7 Three-dimensional Mats 205 8.2.8 Composites 206 8.2.9 Membranes 206 8.3 Properties of Geosynthetics 207 8.3.1 Material and Fibre Properties 207 8.3.2 Geometrical Aspects 208 8.3.3 Mechanical Properties 208 8.3.4 Hydraulic Properties 211 8.3.5 Durability 212 8.4 Applications of Geosynthetics 214 8.4.1 Separation 214 8.4.2 Filtration and Fluid Transmission 218 8.4.3 Reinforcement 211 8.4.4 Containments and Barriers 226 9. Miscellaneous Methods 230 9.1.Introduction 230 9.2 Soil Reinforcement 230 9.2.1 Materials 231 9.2.2 Applications 232 9.2.3 Columns Formed In-Situ 234 9.3 Thermal Methods 236 9.3.1 Stabilization by Heating 236 9.3.2 Stabilization by Cooling 237 9.4 Other Simple Methods 239 9.4.1 Slurry Trench 239 9.4.2 Moisture Barriers 239 9.4.3 Prewetting 239 9.4.4 Void Filling 239 9.5 Improving Rock Stability and Quality 240 9.5.1 Treatment and Purpose 240 9.5.2 Uplift Pressure and Seepage Control 240 9.5.3 Rock Reinforcement 241 9.5.4 Rock Deterioration Prevention 242 9.6 Ground Improvement-A Summary 243 Bibliography 253
8131805948
624.15 / PUR
Ground improvement techniques - New Delhi University Science Press 2011 - xvi,265p.
CONTENTS 1. Formation and Development of Ground 1 1.1 Introduction 1 1.2 Formation of Rock, Soil and Soil Profile 1 1.2.1 Principal Rock Types 1 1.2.2 Origin of Soils 3 1.2.3 Types of Weathering 3 1.2.4 Major Soil Types 4 1.2.5 Soil Profile 7 1.3 Soil Distribution in India 9 1.3.1 Marine Deposits 9 1.3.2 Black Cotton Soils 9 1.3.3 Laterites and Lateritic Soils and Murrums 10 1.3.4 Alluvial Deposits 11 1.3.5 Desert Soils 12 1.3.6 Boulder Deposits 12 1.4 Alterations of Ground After Formation 12 1.4.1 Effect of Seasonal Moisture Variation 12 1.4.2 Effect of Water Seepage and Surface Erosion 14 1.4.3 Effect of Vegetation 14 1.4.4 Effect of Temperature Variation 14 1.4.5 Effect of Vibration 15 1.4.6 Effect of Mining Subsidence and Pumping 15 1.4.7 Effect of Construction Operation 16 1.5 Reclaimed Soils 17 1.5.1 Types of Reclamation Materials 17 1.5.2 Construction Methods 18 1.5.3 Landfill Gas and Leachate 22 115.4 Landfill Liners and Caps 23 1.6 Ground Improvement Potentia 24 1.6.1 Hazardous Ground Conditions 24 1.6.2 Poor Ground Conditions 25 1.6.3 Favourable Ground Conditions 25 1.6.4 Alternative Approaches 26 1.6.5 Geotechnical Processes 26 2. Compaction 28 2.1 Introduction .. 28 2.2 Compaction Mechanics 28 2.2.1 Densification 28 2.2.2 Moisture-Density Relationship 29 2.2.3 Laboratory Compaction Tests 31 2.2.4 Compactive Effort 32 2.2.5 Engineering Behaviour of Compacted Fine-grained Soils 33 2.3 Field Procedure 34 2.3.1 Controlled Compacted FiU 35 2.3.2 Pavement Subgrade 35 2.3.3 Material Selection Factors 35 2.3.4 Borrow Pits 36 2.3.5 Placement and Processing 37 2.3.6 Compaction Specification 37 2.4 Surface Compaction 37 2.4.1 Smooth-Wheel Rollers 38 2.4.2 Sheepsfoot Rollers 38 2.4.3 Grid Rollers 39 2.4.4 Pneumatic-Tired Rollers 39 2.4.5 Other Surface Compaction Devices 41 2.4.6 Dynamic Compaction 42 2.5 Selection of Field Compaction Procedures 43 2.5.1 Choice of Equipment 43 2.5.2 Layer Thickness 44 2.5.3 Wetting and Drying Methods 44 2.5.4 Construction Traffic 44 2.5.5 Selection of Soil and Degree of Compaction 44 2.5.6 Trial Embankments 44 2.6 Compaction Quality Control 45 2.6.1 Moisture Content Measurements 46 2.6.2 In-situ Density Measurements 46 2.6.3 Nuclear Moisture-Density Method 47 2.6.4 Hill's Method 47 3. Drainage Methods 48 3.1 Introduction 48 3.2 Seepage 48 3.3 Filter Requirements 50 3.4 Groundwater 51 3.5 Groundwater and Seepage Control 52 3.6 Methods of Dewatering Systems 53 3.6.1 Open Sumps and Ditches 54 3.6.2 Wellpoint Systems 54 3.6.3 Deep-well Drainage 59 3.6.4 Vacuum Dewatering Systems 60 3.6.5 Dewatering by Electro-osmosis 61 3.7. Design Steps for Dewatering Systems 68 3.7.1 Subsoil Investigation 68 3.7.2 Source and Water Table Details 68 3.7.3 Distance of Wellpoints/Wells from Source of Seepage 70 3.7.4 Effective Well Radius 70 3.7.5 Discharge Computations 70 3.7.6 Design of Filters .. 76 3.7.7 Design and Selection of Well Screens 76 3.7.8 Selection of Pumps and Accessories 76 3.7.9 Wellpointing in Deep Excavations 77 3.7.10 Deep Bored Wells 77 3.7.11 Control of Surface Water 78 3.8. Drains 78 3.8.1 Open Drains 79 3.8.2 Closed Drains 79 3.8.3 Horizontal Drains 79 3.8.4. Drainage After Construction 79 4. Preeompression and Vertical Drains 82 4.1 Introduction 82 4.2 Compressibility of Soils and Consolidation82 4.2.1. Compressibility 82 4.2.2 One-dimensional Consolidation 84 4.2.3 Compressibility Characteristics of Soil Deposits 85 4.2.4 Methods of Evaluating Compressibility 88 4.2.5 Rate of Consolidation 91 4.2.6 Accelerating-Consolidation 93 4.3 Preloading and Surcharge Fills 94 4.3.1 Precompression Principles 94 4.3.2 Preloading Methods 95 4.3.3 Construction Requirements 98 4.4 Monitoring of Compression 99 4-4.1 Predictions from Borings and Tests 100 4.4.2 Prediction from Test Fills 102 4.4.3 Monitoring Time Rate of Settlement 102 4.4.4 Instrumentation 103 4.5 Vertical Drains 104 4.5.1 General Principle 104 4.5.2 Design of Vertical Drains 106 4.5.3 Types and Construction of Vertical Drains 110 4.5.4 Efficiency of Vertical Drains 113 4.5.5 Applications 114 4.6 Dynamic Consolidation 117 4.7 Consolidation by Electro-osmosis 118 5. Vibratipn Methods 124 5.1Introduction 124 5.2 Vibro-Compaction 124 5.2.1 Blasting 125 5.2.2 Vibratory Probe 127 5.2.3. Vibratory Compactors 128 5.3 Vibro-Displacement Compaction 129 5.3.1 Displacement Piles 130 5.3.2 Vibroflotation 130 5.3.3 Sand Compaction Piles 138 5.3.4 Stone Columns 140 5.3.5 Heavy Tamping 145 6. Grouting and Injection 146 6.1 Introduction 146 6.2 Aspects of Grouting 147 6.2.1 Groutability 148 6.2.2 Grouting Materials 149 6.2.3 Suspension Grouts 149 6.2.4 Solution Grouts 152 6.2.5 Compaction Grouting 156 6.3 Grouting Procedure 157 6.3.1 Pre-grouting Site Investigation 157 6.3.2 Grout Holes Pattern158 6.3.3 Grout Characteristics 159 6.3.4 Grouting Plant and Equipmen 160 6.3.5 Injection Methods 163 6.3.6 Grout Injection Measurements and Monitoring 170 6.4 Applications 171 6.4.1 Seepage Control 171 6.4.2 Soil Solidification and Stabilization 174 6.4.3 Vibration Control 175 7. Mechanical, Cementing and Chemical Stabilization 177 7.1 Introduction 177 7.2 Requirements of Soil Stabilization 177 7.3 Mechanical Stabilization 178 7.3.1 Mechanical Stability of Materials 178 7.3.2 Proportioning the Materials 179 7.3.3 Addition or Removal of Soil Particles 180 7.4. Portland Cement (Cementing) Stabilization 180 7.4.1 Nature of Soil 181 7.4.2 Amount of Cement 181 7.4.3 Mixing 183 7.4.4 Moisture Content 183 7.4.5 Compaction Conditions 184 7.4.6 Age and Curing 185 7.4.7 Admixtures for Soil-Cement 185 7.4.8 Construction of Soil-Cement 185 7:5 Bituminous (Cementing) Stabilization 186 7.5.1 Nature of Soil 186 7.5.2 Amount of Asphalt 187 7.5.3 Mixing 187 7.5.4 Compaction Conditions 188 7.5.5 Cure Conditions 188 7.5.6 Construction of Soil-Asphalt 189 7.6 Chemical Stabilization 189 7.6.1 Lime 189 7.6.2 Calcium and Sodium Chlorides 190 7.6.3 Lignin 190 7.6.4 Waterproofers 191 7.6.5 Natural and Synthetic Polymers 191 7.6.6 Aggregants and Dispersants 192 7.6.7 Miscellaneous Chemical Stabilizers 194 7.7 Construction Methods 194 7.7.1 Mix-in-place Method 194 7.7.2 Travelling Plant Method 195 7.7.3 Stationary Plant Method 195 7.7.4. Field Control 196 8. Geosynthetics 199 8.1 Introduction 199 8.2 Geosynthetic Types 199 8.2.1 Raw Materials 200 8.2.2 Wovens 201 8.2.3 Non-wovens 201 8.2.4 Knitted 204 8.2.5 Biogradable 204 8.2.6 Nets and Grids 204 8.2.7 Three-dimensional Mats 205 8.2.8 Composites 206 8.2.9 Membranes 206 8.3 Properties of Geosynthetics 207 8.3.1 Material and Fibre Properties 207 8.3.2 Geometrical Aspects 208 8.3.3 Mechanical Properties 208 8.3.4 Hydraulic Properties 211 8.3.5 Durability 212 8.4 Applications of Geosynthetics 214 8.4.1 Separation 214 8.4.2 Filtration and Fluid Transmission 218 8.4.3 Reinforcement 211 8.4.4 Containments and Barriers 226 9. Miscellaneous Methods 230 9.1.Introduction 230 9.2 Soil Reinforcement 230 9.2.1 Materials 231 9.2.2 Applications 232 9.2.3 Columns Formed In-Situ 234 9.3 Thermal Methods 236 9.3.1 Stabilization by Heating 236 9.3.2 Stabilization by Cooling 237 9.4 Other Simple Methods 239 9.4.1 Slurry Trench 239 9.4.2 Moisture Barriers 239 9.4.3 Prewetting 239 9.4.4 Void Filling 239 9.5 Improving Rock Stability and Quality 240 9.5.1 Treatment and Purpose 240 9.5.2 Uplift Pressure and Seepage Control 240 9.5.3 Rock Reinforcement 241 9.5.4 Rock Deterioration Prevention 242 9.6 Ground Improvement-A Summary 243 Bibliography 253
8131805948
624.15 / PUR