Seismic Engineering

Foreword xiii

Preface xv

Part 1. Earthquakes and Induced Phenomena 1

Chapter 1. Causes of Earthquakes 5

1.1. Tectonic earthquakes 5

1.1.1. First attempts at explanation 5

1.1.2. From continental drift to plate tectonics 9

1.1.3. Seismicity of tectonic origin 20

1.2. Faults 26

1.2.1. Relationship between earthquakes and faults 27

1.2.2. Classification of faults 29

1.2.3. Focal mechanisms 38

1.2.4. Different aspects of rupture 45

1.3. Non-tectonic earthquakes 47

1.3.1. Non-tectonic quakes with natural causes 48

1.3.2. Artificial earthquakes 49

1.3.3. Induced earthquakes 50

Chapter 2. Parameters Used to Define Earthquakes 55

2.1. Elementary theory of elastic rebound 56

2.1.1. Description of the elementary model 56

2.1.2. Energy balance 61

2.1.3. Law of scale 65

2.2. Geometry of the faults 70

2.2.1. Length of fault and length of rupture 70

2.2.2. Well documented examples of fault ruptures 78

2.2.3. Correlations of geometric characteristics of ruptures with moment magnitude 82

2.3. Parametric description of earthquakes 93

2.3.1. Source parameters and effect parameters 93

2.3.2. Different magnitudes 99

Chapter 3. Manifestations of the Seismic Phenomena on the Surface 107

3.1. Deformation of superficial terrains 107

3.1.1. Deformations linked to tectonics 107

3.1.2. Deformations linked to vibratory motions 110

3.2. Seismic waves 114

3.2.1. Different types of seismic waves 114

3.2.2. Ideas on the theory of rays 121

3.2.3. Attenuation of seismic waves 135

3.3. Induced phenomena 143

3.3.1. Soil liquefaction 143

3.3.2. Landslides 148

3.3.3. Tsunamis and seiches 154

3.3.4. Other seismic manifestations 159

Part 2. Strong Ground Motions 161

Chapter 4. Strong Vibratory Motions 165

4.1. Recordings 165

4.1.1. Examples of accelerograms recorded in the near zone 165

4.1.2. Parametric description of the accelerograms 168

4.1.3. The three components of vibratory motion 178

4.2. Attenuation laws of peak values 186

4.2.1. General considerations as regards attenuation laws 186

4.2.2. Examples of attenuation laws for peak values 188

4.2.3. Recommendations for the use of attenuation laws 197

4.3. Directivity effects and site effects 201

4.3.1. Inadequacy of a description based on magnitude and distance 201

4.3.2. Directivity effects 202

4.3.3. Presentation of site effects 210

4.3.4. Causes of site effects 212

Chapter 5. Calculation Models for Strong Vibratory Motions 223

5.1. Orders of magnitude deduced from the basic theory of elastic rebound 223

5.1.1. Limits of the basic theory of elastic rebound for the calculation of motions 223

5.1.2. Model of elastic rebound with multiple ruptures 227

5.1.3. Calculation of the theoretical attenuation laws associated with the model of rebound elasticity with multiple ruptures 229

5.2. Digital source models 232

5.2.1. General considerations pertaining to models of digital simulation of the seismic source 232

5.2.2. Examples of digital simulation of real earthquakes 234

5.3. Practical calculations of the site effects 240

5.3.1. Models of soil behavior 240

5.3.2. Seismic responses of columns of soil 248

5.3.3. Review of the assessment of site effects 267

Part 3. Seismic Hazards 275

Chapter 6. The Spatial and Temporal Distribution of Seismicity 281

6.1. Data available on the spatial and temporal distribution of seismicity 281

6.1.1. Geological data 281

6.1.2. Historical seismicity 283

6.1.3. Archeoseismicity and paleoseismicity 288

6.1.4. Instrumental seismicity 294

6.2. Models of temporal distribution of seismicity 296

6.2.1. Return periods 296

6.2.2. Gutenberg-Richter law 300

6.2.3. Model of a characteristic earthquake 305

6.3. Prediction of earthquakes 307

6.3.1. Seismic precursors 308

6.3.2. Current questions on forecast 309

Chapter 7. Assessment of Seismic Hazard 315

7.1. Methods of assessment of seismic hazard 315

7.1.1. General notes pertaining to different approaches 315

7.1.2. An example of the deterministic method 317

7.1.3. Probabilistic methods 321

7.2. Practices for the evaluation of seismic hazard 326

7.2.1. Normative evaluation and specific evaluation 326

7.2.2. Zoning for the anti-seismic codes 327

7.2.3. Seismic microzoning 330

7.2.4. Orders of magnitude for hazards due to a fault (vibratory motion and surface rupture) 333

7.2.5. Orders of magnitude of vibratory hazard in diffuse seismicity zones 344

7.2.6. Effect of the size of the site on the vibratory hazard in a zone of diffuse seismicity 353

Part 4. Seismic Action 359

Chapter 8. The Seismic Coefficient 365

8.1. The seismic coefficient in past earthquake-resistant codes 365

8.1.1. Notion of seismic coefficient 365

8.1.2. Development of the seismic coefficient 366

8.2. The seismic coefficient in current earthquake-resistant codes 370

8.2.1. The structure of current earthquake-resistant codes 370

8.2.2. The definition of seismic action and the rules of calculation in current earthquake-resistant codes 371

Chapter 9. The Response Spectrum 375

9.1. The response spectrum of elastic oscillators 375

9.1.1. Response spectrum of elastic oscillators associated with a natural accelerogram 375

9.1.2. Response spectrum of elastic oscillators that can be used for designing 386

9.2. Introduction to spectral modal analysis of elastic structures 394

9.2.1. Presentation of a simple example to introduce spectral modal analysis 394

9.2.2. Calculation model for the chosen example 398

9.2.3. Non-damped eigenmodes 401

9.2.4. Calculation of the response for the chosen example 407

9.2.5. Calculation of displacements, accelerations and forces for the chosen example 410

9.3. Structural design spectra 418

9.3.1. Reasons for the general consideration of nonlinearities: the behavior coefficient 418

9.3.2. Elastic and inelastic design spectrum 427

Chapter 10. Other Representations of Seismic Action 433

10.1. Natural or synthetic accelerograms 433

10.1.1. Types of analyses for which accelerogram representation is necessary 433

10.1.2. Choice of accelerograms for linear analysis 435

10.1.3. Choice of accelerograms for nonlinear analysis 437

10.2. Random processes 445

10.2.1. Unfiltered white noise 446

10.2.2. Filtered white noise 452

10.2.3. Theorem of general Brownian motion 456

Part 5. The Effects of Earthquakes on Buildings 467

Chapter 11. Deformation Effects Sustained by Superficial Ground 473

11.1. Effects of irreversible deformations 473

11.1.1. Damage directly due to movements on fault surfaces 473

11.1.2. Damage due to irreversible deformations of the ground in a horizontal direction (other than fault movements) 481

11.1.3. Damage due to irreversible deformation of the ground in a vertical direction (other than fault movements) 487

11.2. Effects of reversible deformation 490

11.2.1. Details of effects due to reversible deformation with respect to those due to irreversible deformations 490

11.2.2. Static or dynamic character of effects due to reversible deformations 492

Chapter 12. Effects of Vibratory Motions 497

12.1. Effects at the structure/subsoil contact 498

12.1.1. Slipping and tilting 498

12.1.2. Rupture of the ground or foundation system 507

12.2. Inertial effects in structures 512

12.2.1. General observations on the inertial effects 512

12.2.2. Damage and destruction patterns due to horizontal inertial effects for concrete structures 513

12.2.3. Damage and destruction patterns due to horizontal inertial effects for steel structures 535

12.2.4. Damage and destruction patterns due to horizontal inertial effects for structures made of masonry or wood 546

12.2.5. Damage patterns due to vertical inertial effect 553

12.2.6. Effects of shocks 556

12.3. Effects on non-structural elements and supported equipment 564

12.3.1. Deformations imposed on non-structural elements 564

12.3.2. Accelerations transmitted to supported equipment 567

Chapter 13. Effects of Induced Phenomena 573

13.1. Effects of naturally induced phenomena 573

13.1.1. Effects of liquefaction 573

13.1.2. Other naturally induced phenomena 575

13.2. Phenomena induced in networks and industrial setups 575

13.2.1. Disruption of the functioning of networks 575

13.2.2. Fires 578

13.2.3. Accidents in industrial facilities 580

Chapter 14. Scales of Macroseismic Intensity 581

14.1. Characterization of the force of earthquakes through assessment of their effects 581

14.1.1. A summary of the history of scales of intensity 581

14.1.2. Description of some scales of intensity 583

14.1.3. Benefits and limitations of the notion of intensity 588

14.2. Numerical correlations using intensities 594

14.2.1. Correlations of intensities with parameters of vibratory motion 594

14.2.2. Magnitude-intensity relations and attenuation laws of intensity 598

Part 6. Seismic Calculations 603

Chapter 15. Linear Seismic Calculation 607

15.1. General observations on linear calculation 607

15.1.1. General formulation with relation to absolute axes 607

15.1.2. Formulations for block movement of supports 612

15.1.3. Representation of damping 619

15.1.4. Notes on modeling 627

15.2. Modal spectral analysis for block translation of supports 637

15.2.1. Eigenmodes and quantities attached to modes 638

15.2.2. Number of modes to be retained and combination of modal responses 653

15.2.3. Combination of effects with three components 667

15.2.4. Some properties of stick models working in shear 673

15.2.5. Continuous models. Example of a uniform cantilever beam 685

Chapter 16. Notions on Soil/Structure Interaction 703

16.1. General observations on soil/structure interaction 703

16.1.1. Presentation of the soil/structure interaction phenomena 703

16.1.2. Kinematic and inertial interaction 709

16.1.3. Radiative (or geometric) damping 713

16.2. Practical consideration of the soil/structure interaction 721

16.2.1. General case 721

16.2.2. Shallow foundations 724

16.2.3. Cases of deep foundations and linear embedded structures 739

16.2.4. Winkler type models 746

Chapter 17. Overview of Nonlinear Calculations 767

17.1. General observations on nonlinear calculations 767

17.1.1. The problem of hypothesis and criteria 767

17.1.2. Methods of giving recognition to nonlinearities 772

17.2. Some examples of nonlinear calculations 781

17.2.1. Tilting of the rigid blocks 781

17.2.2. Basemat uplifts 793

17.2.3. Slipping of massive blocks 800

17.2.4. Plasticization of building structures 808

17.2.5. Nonlinear shock absorbers for bridges 822

17.2.6. Pipelines going through a fault 827

Part 7. Seismic Prevention Tools 833

Chapter 18. Technical Aspects of Prevention 839

18.1. Tools for learning 839

18.1.1. The analysis of past experience 839

18.1.2. Test methods 844

18.1.3. Calculation methods 856

18.2. Earthquake engineering codes for normal risks 858

18.2.1. Area of application and technical objectives of the codes 858

18.2.2. Current and future earthquake engineering codes 863

18.3. Special earthquake resistant devices 866

18.3.1. Earthquake resistant supports made of sandwiched elastomer layers 866

18.3.2. Other special earthquake resistant devices 887

18.3.3. Active control 898

18.4. Earthquake engineering practices for special risk 899

18.4.1. Nuclear power plants and facilities 900

18.4.2. Chemical, oil and gas plants 907

18.4.3. Dams 909

18.5. Seismic diagnosis and reinforcement of the existing framework 913

18.5.1. The different aspects of seismic diagnosis 914

18.5.2. Rehabilitation and reinforcement 928

Bibliography 933

Index 953