FOREWORD xi
PREFACE xiii
ABOUT THE AUTHORS xv
ACKNOWLEDGEMENTS xvii
PHOTOGRAPHY AND ILLUSTRATION CREDITS xix
1 INTRODUCTION AND BRIEF HISTORY 1
1.1 Introduction 1
1.2 A Brief History of Deep Foundations and the Advent of NDT 3
1.3 Deep Foundation Failures and NDT 10
1.4 Deficiencies in Existing Foundations 16
2 DEEP FOUNDATION CONSTRUCTION METHODS 19
2.1 Driven Piles â" Timber, Steel and Concrete 20
2.2 Caissons and Drilled Shafts 28
2.3 Diaphragm Walls, Cut-off Walls and Barrettes 32
2.4 Augered, Cast-in-Place Piles 33
2.5 Micropiles or Minipiles 35
2.6 Stone Columns and other Soil Improvement Techniques 40
3 HOW SOILS AFFECT THE CHOICE OF FOUNDATION 43
4 TRADITIONAL, VISUAL AND NEW INSPECTION METHODS FOR DEEP FOUNDATION CONSTRUCTION 47
4.1 Driven Piles 47
4.2 Augered, Cast-in-Place Piles 48
4.3 Drilled Shafts 50
4.4 The Inspector's Role 55
5 A REVIEW OF FULL-SCALE LOAD-TESTING TECHNIQUES 59
5.1 Static Load-Test Techniques â" Axial Compression 61
5.2 Static Load-Test Techniques â" Axial Tension 68
5.3 Static Load-Test Techniques â" Lateral 68
6 HIGH-STRAIN TESTING FOR CAPACITY AND/OR INTEGRITY 71
6.1 High-Strain Dynamic (Drop-Weight) Testing of Driven Piles 71
6.2 High-Strain Testing of Drilled Shafts and Augered, Cast-in-Place Piles 79
6.3 Modification of Shaft Head for High-Strain Tests 84
6.4 Practical Considerations for Drop-Weight Techniques 87
6.5 HSDT Alternatives 89
6.6 Limitations of High-Strain Dynamic Testing 98
7 LOW-STRAIN SURFACE TESTS â" SONIC ECHO 101
7.1 Sonic Echo (Impulse ECHO) 102
8 SONIC MOBILITY (IMPULSE RESPONSE) 115
8.1 Principles of Impulseâ"Response Curve Interpretation 122
8.2 Practical Considerations 124
8.3 Classification of Signal Responses 127
8.4 Pile Simulation Techniques 132
8.5 Time Domainâ"Velocity Reflectors 135
9 THE IMPEDANCE-LOG ANALYSIS 137
10 LOW-STRAIN DOWN-HOLE TESTS 143
10.1 Introduction 143
10.2 Cross-Hole Sonic Logging 143
10.3 Cross-Hole Tomography 148
10.4 Single-Hole Sonic Logging 152
10.5 Gammaâ"Gamma Logging 155
10.6 Parallel Seismic Testing 162
11 FIELD MOCK-UPS OF DEEP FOUNDTIONS: CLASS-A PREDICTIONS 167
12 THE RELIABILITY OF PILE SHAFT INTEGRITY TESTING 175
12.1 Statistical NDT Sampling Schemes 176
12.2 Methodology Reliability 178
13 CURRENT RESEARCH 189
13.1 Developments in Measurement and Analysis 190
13.2 Electrical Methods 190
13.3 Optical Techniques 198
13.4 Guided Wave Analysis 201
13.5 Statistical Analysis 202
13.6 Self-Consolidating Concrete 203
13.7 Acceptable Vibration Levels 206
13.8 Automated Monitoring Systems 206
13.9 Wireless Acquisition Systems 207
13.10 'SMART' Structures 208
14 THE PLACE OF NONDESTRUCTIVE TESTING AT THE BEGINNING OF THE 21ST CENTURY 211
14.1 Nondestructive testing and load and resistance factor design 214
14.2 Setting up an Effective Quality Management Program 215
14.3 Who's Testing the Tester? 216
14.4 Acceptance Criteria 220
14.5 Evaluating Defects 221
APPENDIX I STRESS-WAVE PROPAGATION IN CYLINDRICAL STRUCTURES 223
1. General Theory 223
2. Determination of Damping 228
3. Determination of Harmonic Response â" Mechanical Impedance 229
4. Resonant frequency of an infinitely long pile 232
5. Impedance input for a finite length pile with unknown mechanical impedance at its base 233
APPENDIX II CONTACT ADDRESSES 235
APPENDIX III STANDARDS REFERRED TO IN THIS BOOK 239
1. Crossâ"Hole Sonic Logging 239
2. GAMMAâ"GAMMA Logging 240
3. High-Strain Testing of Piles 240
4. Impulse-echo and Impulse-Response Tests 240
5. Parallel Seismic 241
6. Static Load Testing of Deep Foundation Shafts 241
APPENDIX IV SAMPLE SPECIFICATIONS FOR NDT METHODS FOR DEEP FOUNDATIONS 243
1. Sample Specification for Low-Strain Testing by Either Impulse Echo or Impulse Response 244
2. Sample Specification for Cross-Hole Sonic Logging (CSL) 248
REFERENCES 255
INDEX 267
