Civil Engineering Applications of Ground Penetrating Radar (eBook)

Andrea Benedetto is Associate Professor of Roads, Railways and Airports at the Department of Engineering of Roma Tre University, Italy.

Introduction 6
Contents 13
Part I GPR Instrumentation 15
Design of Advanced GPR Equipment for Civil Engineering Applications 16
Abstract 16
1 Introduction 17
2 The Radio Frequency System 18
2.1 Introduction 18
2.2 Time Domain GPR 19
2.3 Frequency Domain GPR 20
2.3.1 Principles of Frequency Modulated Continuous Wave (FMCW) Receivers 22
2.3.2 Time Domain to Frequency Domain Transformation 23
2.3.3 Stepped Frequency Continuous Wave Systems 25
3 Ground Penetrating Radar Antennas 26
3.1 Array of Antennas 27
4 Data Processing and Analysis 28
4.1 One-Dimensional Processing 29
4.2 Two-Dimensional Processing 30
4.3 Three-Dimensional Processing 34
4.4 Final Remarks on GPR Processing 35
5 Advanced Equipment for Civil Engineering Applications 36
5.1 Introduction 36
5.2 Dense Array GPR 37
5.3 Bridge Deck Survey with High Resolution Ground Penetrating Radar 40
5.4 The Reconfigurable GPR 45
6 GPR Calibration Procedures 47
7 Electromagnetic Compatibility and Regulations 49
8 Conclusion 50
References 51
Antennas for GPR Systems 53
Abstract 53
1 Introduction 54
2 Most Frequently Used GPR Antennas 56
2.1 Dipole Antennas 57
2.2 End-Fire Tapered Slot Antennas 59
2.3 Spiral Antennas 60
2.4 Horn Antennas 61
2.5 Antenna Arrays 61
3 Overview on Commercial GPR Antennas 63
4 Experimental Characterisation of GPR Antennas 66
5 Electromagnetic Modelling of GPR Antennas 73
6 Conclusions 75
References 76
Part II GPR Surveying of Pavements, Bridges, Tunnels and Buildings Underground Utility and Void Sensing
Innovative Inspection Procedures for Effective GPR Surveying of Critical Transport Infrastructures (Pavements, Bridges and Tunnels) 81
Abstract 81
1 Introduction 81
2 Pavement Diagnostics 82
2.1 Introduction 82
2.2 Equipment and Methods Used 84
2.3 Selected Results and Recommendations 87
3 Bridge Diagnostics 91
3.1 Introduction 91
3.2 Equipment and Methods Used 92
3.3 Selected Results and Recommendations 93
4 Tunnel Diagnostics 97
4.1 Introduction 97
4.2 Equipment and Methods Used 98
4.3 Selected Results and Recommendations 98
5 Common Needs 101
6 Open Issues 102
7 Conclusions 102
References 103
Inspection Procedures for Effective GPR Surveying of Buildings 106
Abstract 106
1 Introduction 107
2 Classifying Buildings 109
3 Common GPR Studies in Buildings Assessment 110
4 Application in Building Diagnosis: Detection of Damages 111
5 Detection of Internal and Buried Elements 117
6 Foundations and Ground 119
7 Standard Methodologies 121
8 New and Experimental Developments 122
9 Conclusion and Open Issues 125
References 127
Inspection Procedures for Effective GPR Sensing and Mapping of Underground Utilities and Voids, with a Focus to Urban Areas 133
Abstract 133
1 Introduction 133
2 Mapping of Underground Utilities 135
2.1 Case Studies 136
2.1.1 Detection of a Main Water Supply Pipe in Stockholm, Sweden 136
2.1.2 Locating Underground Utilities in Malaysia 136
2.1.3 Workshop at Georgia, Atlanta 137
2.1.4 Utility Surveying in Hong Kong 138
2.1.5 Utility Mapping in São Paulo City, Brazil 139
2.1.6 Utility Mapping in Trondheim, Norway 140
2.1.7 Utility Mapping in New York 141
2.1.8 Tree Root Mapping and Utilities, South Africa 141
2.1.9 Water Leakage Detection, USA 142
2.1.10 Water Leakage Detection from Plastic Pipes, Turkey 142
2.1.11 Investigation at Road and Bridge Research Institute 143
2.2 GPR and Other Techniques 144
3 Detection of Voids 145
3.1 Case Studies 146
3.1.1 Detecting Voids Under Roadway Pavements by TxDOT and TTI 146
3.1.2 Detecting Voids Under Roadway in Minnesota 146
3.1.3 Detecting Voids Beneath Concrete Sections in UK 146
3.1.4 Detecting Voids in Malaysia 148
3.1.5 Estimation of Asphalt Air Void Content in Finland, Sweden and Norway 149
3.1.6 Detection of Air Voids During ICF Construction 150
3.1.7 Considerations 150
4 Conclusions 151
References 151
Effective GPR Inspection Procedures for Construction Materials and Structures 154
Abstract 154
1 Introduction 154
2 Electromagnetic Properties of Construction Materials 155
3 Major Directions of the Research Related to Material Properties 158
4 Advanced Data Processing and Inversion 160
5 Challenges in GPR Studies of Bituminous Mixtures and Pavements 161
5.1 Compositional Interpretations of Permittivity Value 162
5.2 GPR Assessment of the Void Content 164
5.3 Characterisation of the Interlayer Interface Structure 165
5.4 Crack Detection and Characterisation 166
6 Conclusions 166
References 167
Determination, by Using GPR, of the Volumetric Water Content in Structures, Substructures, Foundations and Soil 170
Abstract 170
1 Introduction 171
2 GPR Principles 174
2.1 Overview 174
2.2 Maxwell’s Equations 174
2.3 Constitutive Equations 175
3 Volumetric Water Content in Concrete Structures 175
3.1 Time Domain Analysis 176
3.1.1 Reflection Methods 176
3.1.2 Direct Wave Methods 177
3.2 Frequency Domain Analysis 178
4 Volumetric Water Content in Unsaturated Soils 179
4.1 Water Content Estimation Methods by Permittivity Measurements 180
4.1.1 Permittivity Estimation Methods 180
4.1.2 Reflection Methods 180
4.1.3 Single-Offset Reflection Methods 180
4.1.4 Multi-offset Reflection Methods 182
4.1.5 Ground Wave Methods 183
4.1.6 Borehole Transmission Measurements 184
4.1.7 Surface Reflection Methods 185
4.1.8 Inverse Modelling 186
4.1.9 Antenna Equation in the Frequency Domain 186
4.1.10 Green’s Function 187
4.1.11 Model Inversion and Objective Function 187
4.1.12 Petrophysical Relationships 188
Empirical Relationships 188
Volumetric Mixing Formulae 189
Effective Medium Approximations 190
4.2 Water Content Estimation by the Frequency Shift Method 191
4.2.1 Rayleigh Scattering 192
4.2.2 Theoretical Model 192
5 Summary 194
References 195
Part III EM Methods for Near-Field Scattering Problems by Buried Structures Data Processing Techniques
Methods for the Electromagnetic Forward Scattering by Buried Objects 203
Abstract 203
1 Introduction 203
2 The Simulation Layout 206
3 The Finite-Difference Time-Domain Method 209
4 The Cylindrical-Wave Approach 213
5 Conclusions 221
References 221
Development of Intrinsic Models for Describing Near-Field Antenna Effects, Including Antenna-Medium Coupling, for Improved Radar Data Processing Using Full-Wave Inversion 224
Abstract 224
1 Introduction 224
2 Intrinsic Antenna Method 226
2.1 Far-Field Model 226
2.2 Near-Field Model 228
2.3 Determination of the Antenna Characteristic Coefficients 231
3 Model Validation 232
3.1 Numerical Evaluation 232
3.2 Laboratory Evaluation 234
3.3 Field Application 238
4 Conclusion 241
References 242
GPR Imaging Via Qualitative and Quantitative Approaches 244
Abstract 244
1 Introduction 244
2 Measurement Configurations 247
3 Migration Algorithms 249
4 The Scattering Problem 252
5 Linear Inverse Scattering Schemes 255
6 Non-linear Inversion Schemes 259
6.1 Deterministic Inversion Procedures 259
6.2 Stochastic Inversion Procedures 265
7 Qualitative Inversion Schemes 267
8 Hybrid Inversion Schemes 272
9 Open Issues and New Prospective 273
References 274
GPR Data Processing Techniques 286
Abstract 286
1 Introduction 286
2 GPR Data Processing 287
3 Deconvolution 289
4 Velocity Analysis of GPR Data 291
5 Migration 291
6 Noise Suppression 292
7 Attributes 293
8 Applications 294
9 Omalos Survey 294
10 Sandbox Experiment 295
11 Clay Intrusion Estimation 297
12 Conclusions 298
References 299
Part IV Different Applications of GPR and Other NDT Technologies in CE 303
Applications of GPR for Humanitarian Assistance and Security 304
Abstract 304
1 Introduction 304
2 Landmine and UXO Detection 306
3 Investigation of Underground Constructions 313
4 Human Remains and Life Detection 316
5 Conclusion 322
References 324
Applications of GPR in Association with Other Non-destructive Testing Methods in Surveying of Transport Infrastructures 330
Abstract 330
1 Introduction 330
2 Applications of GPR 331
2.1 Roads and Pavements 331
2.2 Concrete Structures 335
2.3 Masonry Structures 338
2.4 Tunnels 340
3 Conclusion 342
References 342
Advanced Electric and Electromagnetic Methods for the Characterization of Soil 346
1 Introduction 346
2 Proximal Soil Sensing 347
3 Electric and Electromagnetic Soil Properties 348
3.1 Electrical Conductivity 348
3.2 Magnetic Susceptibility 349
3.3 Dielectric Permittivity 350
4 Electrical Resistivity Sensors 351
4.1 Principle 351
4.2 Instrumentation 351
4.3 What Can Be Measured, Advantages, Limitations 353
5 Ground Penetrating Radar 354
5.1 Principle 354
5.2 Instrumentation 355
5.3 What Can Be Measured, Advantages, Limitations 356
6 Electromagnetic Induction Sensors 356
6.1 Principle 356
6.2 Electromagnetic Induction Sensors 358
6.3 What Can Be Measured, Advantages, Limitations 359
7 Conclusions 360
References 361
Applications of Radar Systems in Planetary Sciences: An Overview 363
Abstract 363
1 Introduction 363
2 Planetary Radar Systems: Investigations on Venus and Titan 364
3 Radar Missions and Explorations Over History 366
3.1 Exploration of the Moon 366
3.2 Mars Exploration 367
3.3 Future Challenges in Planned Mars Missions 369
3.4 Recent Advances and Perspectives in GPR-Based Planetary Missions 370
4 Conclusions 370
References 371