Fundamentals of Seismic Loading on Structures

Preface xv

Acknowledgements xvii

1 Introduction to Earthquakes 1

1.1 A Historical Perspective 1

1.2 The Nature of Earthquakes 8

1.3 Plate Tectonics 9

1.4 Focus and Epicentre 14

1.5 Seismic Waves 14

1.6 Seismometers 17

1.7 Magnitude and Intensity 22

1.8 Reid’s Elastic Rebound Theory 27

1.9 Significant Milestones in Earthquake Engineering 27

1.10 Seismic Tomography 28

1.11 References 32

2 Single Degree of Freedom Systems 35

2.1 Introduction 35

2.2 Free Vibration 38

2.3 Periodic Forcing Function 42

2.4 Arbitrary Forcing Function 49

2.5 References 53

3 Systems with Many Degrees of Freedom 55

3.1 Introduction 55

3.2 Lumped Parameter Systems with Two Degrees of Freedom 55

3.3 Lumped Parameter Systems with more than Two Degrees of Freedom 56

3.4 Mode Superposition 65

3.5 Damping Orthogonality 67

3.6 Non-linear Dynamic Analysis 68

3.7 References 73

4 Basics of Random Vibrations 75

4.1 Introduction 75

4.2 Concepts of Probability 76

4.3 Harmonic Analysis 85

4.4 Numerical Integration Scheme for Frequency Content 91

4.5 A Worked Example (Erzincan, 1992) 92

4.6 References 95

5 Ground Motion Characteristics 97

5.1 Characteristics of Ground Motion 97

5.2 Ground Motion Parameters 110

5.3 References 136

6 Introduction to Response Spectra 141

6.1 General Concepts 141

6.2 Design Response Spectra 149

6.3 Site Dependent Response Spectra 163

6.4 Inelastic Response Spectra 174

6.5 References 178

7 Probabilistic Seismic Hazard Analysis 181

7.1 Introduction 181

7.2 Basic Steps in Probabilistic Seismic Hazard Analysis (PSHA) 183

7.3 Guide to Analytical Steps 192

7.4 PSHA as Introduced by Cornell 195

7.5 Monte Carlo Simulation Techniques 200

7.6 Construction of Uniform Hazard Spectrum 207

7.7 Further Computational Considerations 212

7.8 References 216

8 Code Provisions 219

8.1 Introduction 219

8.2 Static Force Procedure 234

8.3 IBC 2006 239

8.4 Eurocode 8 244

8.5 A Worked Example (IBC 2000) 249

8.6 References 276

9 Inelastic Analysis and Design Concepts (with Particular Reference to H-Sections) 279

9.1 Introduction 279

9.2 Behaviour of Beam Columns 280

9.3 Full Scale Laboratory Tests 283

9.4 Concepts and Issues: Frames Subjected to Seismic Loading 289

9.5 Proceeding with Dynamic Analysis (MDOF systems) 290

9.6 Behaviour of Steel Members under Cyclic Loading 293

9.7 Energy Dissipating Devices 296

9.8 References 303

10 Soil-Structure Interaction Issues 305

10.1 Introduction 305

10.2 Definition of the Problem 305

10.3 Damaging Effects due to Amplification 308

10.4 Damaging Effects Due to Liquefaction 316

10.5 References 321

11 Liquefaction 323

11.1 Definition and Description 323

11.2 Evaluation of Liquefaction Resistance 325

11.3 Liquefaction Analysis – Worked Example 332

11.4 SPT Correlation for Assessing Liquefaction 338

11.5 Influence of Fines Content 348

11.6 Evaluation of Liquefaction Potential of Clay (cohesive) Soil 349

11.7 Construction of Foundations of Structures in the Earthquake Zones Susceptible to Liquefaction 350

11.8 References 353

12 Performance Based Seismic Engineering – An Introduction 357

12.1 Preamble 357

12.2 Background to Current Developments 358

12.3 Performance-Based Methodology 360

12.4 Current Analysis Procedures 365

12.5 Second Generation Tools for PBSE 370

12.6 References 372

Index 375