Soil Dynamics and Foundation Modeling (eBook)

Dr. Junbo Jia is an engineering expert at Aker Solutions, Norway. He is currently a committee member of ISO TC67/SC7 Fixed Steel Structures and an invited member of Eurocode 3. He has been invited as speakers, lecturers for industry training and university graduate courses, and permanent members of PhD examination committees by various organizations and research institutes. He serves on editor boards of four international scientific journals and is listed in several global versions of the Who's Who publication. Dr. Junbo Jia is authors of two Springer engineering monographs on Applied Dynamic Analysis and Earthquake Engineering. He is currently an editor of a book volume: Structural Engineering in Vibrations, Dynamics and Impacts to be published by CRC press.

Preface 6
About this Book 9
Contents 10
About the Author 20
Soil Behavior and Dynamics 21
1 Soil Behavior 23
1.1 Introduction 23
1.2 Soil Classification 23
1.3 Saturation, Water Table, Drainage, and Capillary Effect 25
1.3.1 Saturation 25
1.3.2 Drainage 26
1.3.3 Water Table 27
1.3.4 Capillary Effect 28
1.4 Effective Stress 28
1.5 Mohr’s Circle for Describing Stress Condition 33
1.6 Soil Failure 37
1.6.1 Shear Failure for Cohesionless Soils 38
1.6.2 Shear Failure for Cohesive Soils 38
1.7 Total Stress Analysis Versus Effective Stress Analysis 41
1.8 Clay Soil Consistency 42
1.9 Testing Methods to Measure Shear Strength 44
1.9.1 Laboratory and Field Test Methods 44
1.9.2 Direct Shear Test 44
1.9.3 Triaxial Shear Test 45
1.9.3.1 Method 45
1.9.3.2 Types of Triaxial Shear Test 46
1.9.3.3 Standards Describing Triaxial Shear Test 49
1.9.4 Vane Shear Test 49
1.9.5 Standard Penetration Test (SPT) 51
1.9.5.1 Performing SPT 51
1.9.5.2 Determine (N1)60 52
1.9.5.3 Assess Soil Class Using SPT Test 54
1.9.6 Cone Penetration Test (CPT) 56
1.9.7 Other in Situ Testing Methods 62
1.10 Soil Stiffness and Poisson’s Ratio 62
1.11 Consolidation 66
1.11.1 Introduction to Consolidation 66
1.11.2 Effects of Consolidation on Soil Stiffness 67
1.11.3 Effects of Consolidation for Shallow Foundations 68
1.11.4 Effects of Consolidation and Aging for Deep Foundations 70
1.12 Obtaining Soil Parameters for Engineering Design 73
1.13 Allowable Stress Design and Load Resistance Factor Design 76
1.13.1 Allowable Stress Design 76
1.13.2 Load Resistance Factor Design 76
1.13.2.1 Method 76
1.13.2.2 Probability of Failure 79
1.13.2.3 Probability of Failure for Nonlinear Safety Margin Functions 85
1.13.2.4 Monte Carlo Method for Calculating Probability of Failure 87
1.13.3 Levels of Reliability Method 89
1.13.4 Essential Differences Between LRFD and ASD 90
1.13.5 Applying Partial Safety Factors in Geotechnical Analysis 91
1.14 Incorporating Uncertainties of Soil Parameters 91
1.15 General Soil Conditions at Offshore Sites Worldwide 93
2 Dynamic and Cyclic Properties of Soils 95
2.1 Introduction 95
2.2 Equivalent Linear Soil Models 98
2.2.1 Equivalent Shear Modulus Modeling 98
2.2.2 Determination of G_{{{{/bf max}}}} 102
2.2.3 Equivalent Damping Modeling 106
2.3 Soil Stiffness and Damping Modeling in an Equivalent Linear Model 109
2.3.1 Trends in Dynamic Soil Properties and Strain Thresholds 109
2.3.2 Stiffness Modeling 113
2.3.2.1 General 113
2.3.2.2 Modulus Reduction Curve 113
2.3.3 Damping Modeling 115
2.4 Nonlinear Soil Models 117
2.4.1 General 117
2.4.2 Cyclic Nonlinear Soil Models 118
2.4.3 Small Strain Damping Modeling in Time-Domain Analysis 120
2.4.4 Nonlinear Constitutive Soil Models 123
2.5 Strain Rate Effects Due to Seismic Loading 126
2.6 Differences Between Soil Properties Subjected to Earthquake Loadings and Ocean Wave Loadings 127
3 Site-Response Analysis in Geotechnical Earthquake Engineering 129
3.1 General 129
3.2 Site Period 135
3.2.1 General 135
3.2.2 Influence of Soil Depth on the Site Period 139
3.3 Non-stationary and Peak Ground Motions 141
3.3.1 Peak Ground Motions and Their Relationship with Magnitude and Intensity 141
3.3.2 Contribution of Body and Surface Wave to Ground Motions 144
3.3.3 Moving Resonance 145
3.4 Measuring Soil Amplification or De-amplification 146
3.5 One-Dimensional Site-Response Analysis 146
3.5.1 One-Dimensional Seismic Wave Propagation Analysis 146
3.5.2 One-Dimensional Frequency-Domain Site-Response Analysis Using Equivalent Linear Soil Model 153
3.5.2.1 Method 153
3.5.2.2 Applicabilities of Equivalent Linear Models 159
3.5.2.3 Procedure for Performing One-Dimensional Analysis 161
3.5.3 One-Dimensional Site-Response Analysis Using Nonlinear Soil Models 163
3.6 Surface (Topographic) and Subsurface Irregularities 166
3.6.1 General 166
3.6.2 Effects of Irregular Surface Topology 167
3.6.3 Effects of Subsurface Irregularity 169
3.7 Two- and Three-Dimensional Site-Response Analyses 171
3.7.1 Applicability of One-, Two-, and Three-Dimensional Site-Response Analyses 171
3.7.2 Seismic Wave Propagation Effects 172
3.7.3 Site Geometric Effects 175
3.8 Using Site-Response Analysis Results for Seismic Analysis 179
3.9 Characteristics of Site Responses 179
3.9.1 Horizontal Ground Motions 179
3.9.2 Vertical Ground Motions 181
3.10 Vertical Ground Motion Calculations 182
3.10.1 Site-Response Analysis for Calculating Vertical Ground Motions 182
3.10.2 V/H Spectrum 183
3.11 Water Column Effects on Seismic Ground Motions 185
4 Record Selection for Performing Site-Specific Response Analysis 186
4.1 General 186
4.2 Selections of Motion Recordings 187
4.3 Modification of the Recordings to Fit into the Design Rock Spectrum 188
4.3.1 Direct Scaling 188
4.3.2 Spectrum/Spectral Matching 188
4.3.3 Pros and Cons of Direct Scaling and Spectrum Matching 192
4.4 Performing the Site-Response Analysis Using Modified/Matched Recordings 193
4.5 Sources of Ground Motion Recording Data 194
5 Soil–Structure Interaction 195
5.1 Introduction 195
5.2 Direct and Substructure Approach 196
5.2.1 Direct Analysis Approach 196
5.2.2 Substructure Approach 196
5.3 Kinematic Interaction 198
5.3.1 Objective 198
5.3.2 Applications 199
5.4 Subgrade Impedances and Damping 199
5.4.1 Objective 199
5.4.2 Applications for Pile Foundations 199
5.4.3 Applications for Shallow Foundations 200
5.5 Inertial Interaction 202
5.5.1 Objective 202
5.5.2 Applications 204
5.6 Effects of Soil–Structure Interaction 204
5.7 Boundary Modeling in Geotechnical Analysis 205
5.8 Remarks on Substructure Approach 207
6 Seismic Testing 209
6.1 Introduction 209
6.2 Field Testing 210
6.2.1 General 210
6.2.2 Low-Strain Field Test 210
6.2.2.1 Surface Reflection Test 212
6.2.2.2 Surface Refraction Test 214
6.2.2.3 Surface Wave Method 218
6.2.2.4 Cross-Hole Test 221
6.2.2.5 Down-Hole (Up-Hole) Test 223
6.2.2.6 Seismic Cone Penetrometer Test 225
6.2.2.7 Suspension Logging Test 226
6.2.3 High-Strain Field Test 228
6.3 Laboratory Element Testing 229
6.3.1 Low-Strain Element Test 229
6.3.1.1 Resonant Column Test 229
6.3.1.2 Other Low-Strain Element Tests 234
6.3.2 High-Strain Element Test 235
6.3.2.1 Cyclic Direct Shear Test and Cyclic Triaxial Test 235
6.3.2.2 Cyclic Torsional Shear Test 235
6.4 Model Testing 236
6.4.1 Shaking Table Test 236
6.4.2 Centrifuge Test 242
7 Liquefaction 244
7.1 Introduction to Liquefaction 244
7.1.1 Causes of Liquefactions 244
7.1.2 Liquefaction Damages 248
7.2 Evaluation of Liquefaction Initiation 253
7.2.1 Introduction 253
7.2.2 Cyclic Stress Approach 254
7.2.2.1 Calculation of Cyclic Stress Ratio (CSR) Caused by Earthquake Loading 255
7.2.2.2 Determine Cyclic Resistance Ratio (CRR) from Recommended Charts 258
7.2.3 Cyclic Strain Approach 265
7.3 Liquefaction Mitigations 266
8 Slope Stability Due to Seismic Loading 268
8.1 General 268
8.2 Pseudo-Static Analysis Approach 269
8.3 Dynamic Stress-Deformation Analysis Approach 272
8.4 Newmark Sliding-Block Approach 273
8.4.1 Rigid-Block Analysis 274
8.4.2 Decoupled Analysis 276
8.4.3 Coupled Analysis 277
8.4.4 Selection of Analysis Methods 277
8.4.5 Potential of Landslides Based on the Predicted Displacement 278
8.5 Testing Method 279
8.6 Post-Earthquake Slope Instability Assessment 279
8.7 Landslides 280
8.7.1 General 280
8.7.2 Assessment of Regional Landslide Potential by Arias Intensity 281
Offshore Structures and Earthquake Engineering 283
9 Offshore Structures and Hydrodynamic Modeling 284
9.1 Introduction to Offshore Structures 284
9.1.1 Offshore Platforms 284
9.1.2 Offshore Wind Turbine Substructures and Foundations 292
9.2 Dynamic Design of Structures 298
9.2.1 Dynamics Versus Statics 298
9.2.2 Characteristics of Dynamic Responses 303
9.2.3 Frequency Range of Dynamic Loading 309
9.3 Difference Between Offshore and Land-Based Structures 314
9.4 Hydrodynamic Modeling of Offshore Structures 317
9.4.1 Introduction to Hydrodynamic Force Calculation 317
9.4.2 Effects of Drag Forces 323
9.4.3 Effects and Determination of Added Mass 323
9.4.4 Effects of Buoyancy 325
9.4.5 Effects and Modeling of Marine Growth 326
10 Representation of Seismic Ground Motions 329
10.1 General 329
10.2 Earthquake Excitations Versus Dynamic Ocean Wave, Wind, and Ice Loading 330
10.3 Power Spectrum of Seismic Ground Motions 333
10.3.1 Introduction to Fourier and Power Spectrum 333
10.3.1.1 Fourier Spectrum 333
10.3.1.2 Power Spectrum Density 338
10.3.2 Power Spectrum of Seismic Ground Motions 342
10.4 Response Spectrum 344
10.4.1 Background 344
10.4.2 Elastic Response and Design Spectrum 346
10.4.2.1 Elastic Response Spectrum 346
10.4.2.2 Elastic Design Spectrum 357
10.4.2.3 Effects of Damping 363
10.4.2.4 Shear Wave Velocity Estimation with Shallow Soil Depth or Soils and Rock Below 30 M 364
10.4.3 Ductility-Modified (Inelastic) Design Spectrum Method 365
10.4.3.1 Ductility for Elastic-Perfect-Plastic Structures 365
10.4.3.2 Construction Ductility-Modified (Inelastic) Design Spectrum Method 369
10.5 Time History Method 371
10.5.1 General Method 371
10.5.2 Drift Phenomenon and Its Correction 372
11 Seismic Hazard Assessment 376
11.1 Seismic Hazard Analysis 376
11.1.1 Introduction 376
11.1.2 Deterministic Seismic Hazard Analysis (DSHA) 378
11.1.3 Probabilistic Seismic Hazard Analysis (PSHA) 380
11.1.3.1 Define Earthquake Source and Geometry 381
11.1.3.2 Establish Attenuation Relationship 387
11.1.3.3 Develop Seismic Hazard Curve 388
11.1.3.4 Construction of Spectra Acceleration at Discrete Periods 395
11.1.4 Deaggregation (Disaggregation) in PSHA for Multiple Sources 398
11.1.5 Logic Tree Method 403
11.2 Seismic Hazard Map 405
11.3 Apply PSHA for Engineering Design 408
11.4 Conditional Mean Spectrum 412
11.5 The Neo-deterministic Approach 418
11.6 Forecasting “Unpredictable” Extremes 422
Shallow Foundations 424
12 Bearing Capacity of Shallow Foundations 425
12.1 Introduction 425
12.2 Failure of Shallow Foundations 427
12.3 Bearing Capacity of Drained Soil 433
12.3.1 Bearing Capacity Due to General Shear Failure 433
12.3.2 Bearing Capacity Due to Local and Punching Shear Failure 437
12.3.3 Bearing Capacity for Layered Soil 438
12.4 Bearing Capacity for Undrained Clay 438
12.5 Bearing Capacity of Unliquefiable Soil Subjected to Seismic Loading 439
12.6 Bearing Capacity Control of Soils with Liquefaction Potential Subjected to Seismic Loading 440
12.7 Sliding Stability of Shallow Foundations 442
12.8 Effects of Cyclic Loading on Shallow Foundations 442
12.9 Piping Actions and Scour for Shallow Foundations 444
13 Modeling of Shallow Foundation Dynamics 446
13.1 Foundation Impedance 446
13.2 Combination of Damping for Foundations and Superstructures 461
Pile Foundations 463
14 Introduction to Deep Foundations 464
15 Capacity Control, Modeling of Pile Head Stiffness, and Mitigation Measures to Increase Pile Capacity 474
15.1 Capacity Control of Pile Foundations 474
15.2 Representation of Piles, Surrounding Soils, and Soil–Pile Interactions 476
15.3 Winkler Foundation Modeling 481
15.4 Simplified Calculation of Pile Stiffness and Natural Frequency for Pile–Structure System 484
15.4.1 Stiffness of Pile–Structure System 484
15.4.2 Pile Head Stiffness 486
15.4.3 Natural Frequency of Non-uniform Beams 486
15.5 Increasing Existing Pile Foundation Capacity for Offshore Structures 489
16 Lateral Force–Displacement of Piles—p-y Curve 490
16.1 Introduction to p-y Curve 490
16.2 Calculation of pu for Clays 495
16.3 Calculation of pu for Sands 499
16.4 Constructing p-y Curves for Clays 500
16.5 Constructing p-y Curves for Sands 504
16.6 Effects of Cyclic Loading on p-y Curves and Structural Dynamic Response 507
16.7 Effects of Dynamic Loading on p-y Curves 512
16.8 Effects of Pile Diameter on Lateral Load–Displacement Behavior 514
16.8.1 Introduction 514
16.8.2 Effects of Pile Diameter Under Sand Soil Conditions 517
16.8.2.1 Method Proposed by Wiemann et al. 517
16.8.2.2 Sørensen Method 517
16.8.2.3 Method Proposed by Kallehave et al. 518
16.8.2.4 Method Proposed by Kirsch et al. 518
16.8.2.5 Evaluation of the Proposed Methods 519
16.8.2.6 Method Proposed by Thieken et al. 521
16.8.3 Effects of Pile Diameter Under Clay Soil Conditions 521
16.8.3.1 Method Proposed by Kim et al. 521
16.8.3.2 Method Proposed by Kirsch et al. 522
16.8.3.3 Method Proposed by Stevens and Audibert 522
16.8.3.4 Method Proposed by O’Neill and Gazioglu 524
16.8.3.5 Method Proposed by Carter and Ling 525
16.8.3.6 Evaluations of Different Methods 525
16.9 Hybrid Spring Model for Modeling Piles’ Lateral Force–Displacement Relationship 527
17 Axial Force–Displacement of Piles: t-z and Q-z Curve 529
17.1 Pile–Soil Modeling Under Axial Pile Loading 529
17.2 Axial Compression Capacity 530
17.3 Axial Tension Capacity 537
17.4 Determining Unit Friction Capacity for Cohesive Soils 539
17.4.1 Friction Capacity for Highly Plastic Clays by API 539
17.4.2 Friction Capacity for Other Types of Clays by API 540
17.4.3 Friction Capacity by Revised API Method (?-Method) 541
17.4.4 Friction Capacity for Long Piles in Clay 541
17.4.5 ?-Method 542
17.4.6 ?-Method 543
17.5 Determining Unit Friction Capacity for Cohesionless Soils 543
17.5.1 Unit Friction Capacity by API 1993 Method 544
17.5.2 Unit Friction Capacity by API 2000 Method 545
17.6 Modeling of Pile–Soil Friction Behavior by FEM 546
17.7 Modeling of t-z Curves 547
17.8 Determining Unit End-Bearing Capacity for Cohesive Soils 548
17.9 Determining Unit End-Bearing Capacity for Cohesionless Soils 549
17.10 Modeling of Q-z Curves 549
17.11 Effects of Soil Layer Boundaries on End-Bearing Capacity 550
17.12 Soil Plugging 551
17.13 Recently Developed CPT-Based Methods to Assess the Axial Pile–Soil Interaction Capacity 553
17.13.1 Skin Friction Calculation for CPT-Based Method 554
17.13.2 End-Bearing Capacity Calculation for CPT-Based Method 556
17.13.2.1 Cone Tip Resistance Calculation 556
17.13.2.2 End-Bearing Capacity by ICP-05 Method 557
17.13.2.3 End-Bearing Capacity by UWA-05 Method 558
17.13.2.4 End-Bearing Capacity by Fugro-05 Method 559
17.13.2.5 End-Bearing Capacity by NGI-05 Method 559
17.13.3 Comments on the CPT-Based Methods 560
17.14 Ultimate End-Bearing Capacity from Tests 562
17.15 Effects of Cyclic Loading on Axial Capacity of Piles 562
18 Torsional Moment–Rotation Relationship 566
18.1 General 566
18.2 Behavior of Single Piles Under Torsion 567
18.3 Behavior of Pile Groups Under Torsion 571
19 Modeling, Response Calculation, and Design of Piles Under Seismic Loading 572
19.1 Loading of Piles During Earthquakes 572
19.2 Pseudo-static Approach 575
19.2.1 Inertia Loading on Piles 575
19.2.2 Kinematic Loading and Pile Response 576
19.2.2.1 Kinematic Loading and Pile Response for Homogeneous Soil Layers 577
19.2.2.2 Kinematic Loading and Pile Response for Layered Soils 579
19.3 The Location for Transferring the Earthquake Input Energy from Soils to Piles or Shallow Foundations 583
19.4 Simple Modeling of Pile Impedance 584
19.5 Determination of Pile Impedance 586
19.6 Kinematic and Inertia Loading Modeling in the Direct Analysis Approach 591
20 Scour for Pile Foundations 595
20.1 Introduction to Scour 595
20.2 Influence of Scours 598
20.3 Scour Modeling 600
20.4 Determination of Scour Depth for Single Piles and Bridge Piers 601
20.5 Scour Depth Influenced by Pile Groups 603
20.6 Influence of Scour on Pile’s Capacity 605
20.6.1 Influence of Scour on Axial Pile Capacity 605
20.6.2 Influence of Scour on Lateral Pile Capacity 605
20.6.3 The Consideration of Scour in Pile Designs by DNV-OS-J101 606
21 Effects of Pile Group, Adjacent Structures, and Construction Activities 607
21.1 Introduction to Pile Group 607
21.2 Pile Group Effects Under Axial Loading 611
21.2.1 General 611
21.2.2 Modifying Friction Resistance 614
21.2.3 Modifying Tip Resistance 615
21.3 Pile Group Effects Under Lateral Loading 615
21.3.1 General 615
21.3.2 Modifying Soil Resistance 618
21.4 Effects of Cyclic Loading on Pile Group Behavior 621
21.5 Effects of Dynamic Loading on Pile Group Behavior 621
21.5.1 General 621
21.5.2 Modifying Pile Resistance Due to Dynamic Loading 621
21.5.2.1 Dynamic t–z Curve 621
21.5.2.2 Dynamic p–y Curve 622
21.6 Modifying Pile Displacement to Account for Both Pile Group and Dynamic Loading Effects 622
21.7 Pile Cap 624
21.8 Influence of Adjacent Structures and Construction Activities on the Existing Piled Foundations 625
21.8.1 Problem Description 625
21.8.2 Pile–Soil Interaction Influenced by the Presence of Spudcan 626
21.8.3 Influence of Pile–Soil Interaction Due to Construction Activities 628
22 Grout Connections 630
22.1 Introduction 630
22.2 Grout Connection Capacity Control 632
22.3 Typical Mechanical Properties of Grout 632
23 Vertical Piles Versus Inclined/Battered/Raked Piles 634
23.1 Introduction to Inclined/Battered Piles 634
23.2 Seismic Performance of Pile Groups with Battered Piles 634
23.3 Wave- and Wind-Induced Response of Pile Group with Battered Piles 637
24 Negative (Downward) Friction and Upward Movement 641
24.1 Negative Friction 641
24.2 Upward Movement 644
25 Anchor Piles 645
25.1 Introduction 645
25.2 Behavior of Anchor Lines 647
25.2.1 Behavior of Anchor Lines on Seabed 647
25.2.2 Behavior of Buried Anchor Lines 648
25.3 Anchor Pile Padeye(s) 650
25.4 Seismic Response of Anchor Pile 652
25.5 Required Safety Factors for Offshore Anchor Pile Design 652
25.6 Fatigue Capacity Control of Anchor Line–Pile Connection 653
25.6.1 Method 653
25.6.2 Derivation of Hot-Spot Stress 656
26 Suction Piles/Caissons 659
26.1 Introduction 659
26.2 Suction Pile Installations 660
26.3 Modeling and In-place Capacity Control for Suction Piles 662
26.4 Modeling of Suction Piles Subjected to Seismic Loading 665
26.5 Advantages of Suction Piles/Caissons 668
26.6 Engineering Applications 669
26.6.1 Application for Offshore Structures 669
26.6.2 Application as Deep-Water Anchors 671
26.6.3 Application for Subsea Production Facility Foundations 672
27 General Design Issues for Offshore Foundations and Relevant International Codes and Guidelines 673
Appendix 676
References 677
Index 728