Seismic Risk and Engineering Decisions

Chapter 1 Introduction

Chapter 2 Earthquakes and Earthquake Prediction

    2.1 The earthquake process

    2.2 Models of the earthquake process

         2.2.1 An earthquake mechanism: Reid's theory

         2.2.2 Plate tectonics

         2.2.3 Stochastic models for large earthquakes

    2.3 The search for earthquake predictors

         2.3.1 Earthquakes at plate boundaries: seismic gaps

         2.3.2 Earthquake precursors: foreshocks

         2.3.3 Monitoring crustal movements

         2.3.4 Premonitory changes in seismic velocities

         2.3.5 Other premonitory effects: the dilatancy model

         2.3.6 Elastic and viscoelastic modeling of tectonic plates

    References

Chapter 3 Geological Criteria for Evaluating Seismicity

    3.1 Introduction

    3.2 California

    3.3 Turkey

    3.4 Japan

    3.5 Philippines

    3.6 China

    3.7 Thrust faults

    3.8 Conclusions

    Acknowledgments

    References

Chapter 4 Soil Dynamics: Behavior Including Liquefaction

    4.1 Introduction

         4.1.1 Nature of soils: Phases and stresses

         4.1.2 Drainage conditions in earthquake problems

         4.1.3 Independent variables and test conditions in soil dynamics

         4.1.4 Stable and unstable soil conditions

    4.2 Stress—strain relationship under stable conditions

         4.2.1 Introduction

         4.2.2 Shear modulus for small-amplitude vibration

         4.2.3 Internal damping

         4.2.4 Stress—strain relationships in large-amplitude cyclic deformation

         4.2.5 Strength under cyclic loading

    4.3 Local amplification

         4.3.1 Nature of the phenomenon. Problems of interpretation

         4.3.2 Analytical models

         4.3.3 Effects of weak interbedded layers

         4.3.4 Modification of design spectra according to soil profile

    4.4 Compaction and loss of strength

         4.4.1 Introductory remarks

         4.4.2 Volume change under vibration

         4.4.3 Loss of strength of loose saturated sands and soft cohesive soils

         4.4.4 Cyclic mobility of cohesionless soils in laboratory tests

         4.4.5 Effects of permeability, drainage path and boundary conditions

         4.4.6 Evaluation of liquefaction and cyclic mobility potentials

         4.4.7 Loss of strength and fatigue effects in cohesive soils

    4.5 Soil exploration

         4.5.1 Considerations on field exploration programs

         4.5.2 Exploration methods

    References

Chapter 5 The Physics of Earthquake Strong Motion

    5.1 Introduction

    5.2 Physical parameters of the earthquake source

         5.2.1 The elastic rebound mechanism

         5.2.2 Point source theory

         5.2.3 Far-field approximation

         5.2.4 Far-field radiation from a double-couple point source

         5.2.5 Seismic moment and fault slip

         5.2.6 Energy and stress

         5.2.7 Frictional heat generation and seismic efficiency

         5.2.8 Stress drop, fault displacement, and source dimension

         5.2.9 Effective accelerating stress

    5.3 Earthquake modeling

         5.3.1 Instantaneous stress pulse model

         5.3.2 Crack tip stress singularity

         5.3.3 Focussing of energy by rupture propagation

         5.3.4 Approximate solutions to the dynamic problem of propagating ruptures

         5.3.5 Foam-rubber model

         5.3.6 Geometrical and boundary-condition effects

         5.3.7 Complexity, scattering and attenuation effects

    5.4 Conclusion — Estimates of maximum probable near-source ground motion

    Acknowledgements

    References

Chapter 6 Seismicity

    6.1 On seismicity models

    6.2 Intensity attenuation

         6.2.1 Intensity attenuation on firm ground

    6.3 Local seismicity

         6.3.1 Magnitude-recurrence expressions

         6.3.2 Variation with depth

         6.3.3 Stochastic models of earthquake occurrence

         6.3.4 Influence of the seismicity models on seismic risk

    6.4 Assessment of local seismicity

         6.4.1 Bayesian estimation of seismicity

    6.5 Regional seismicity

         6.5.1 Intensity-recurrence curves

         6.5.2 Seismic probability maps

         6.5.3 Microzoning

    References

Chapter 7 Tsunamis

    7.1 Introduction

         7.1.1 Some data

         7.1.2 Relationships among earthquake magnitudes, aftershock areas, tectonic displacements and tsunami damage

         7.1.3 Landslide and subaqueous slide-generated tsunamis

    7.2 Theory of the generation of tsunamis

         7.2.1 Initial elevation or depression of the water surface

         7.2.2 Vertical displacement of bottom: linear theory

         7.2.3 Moving boundary: linear theory and hydraulic-model studies

         7.2.4 Large high-speed horizontal motion of vertical plane boundary

         7.2.5 Exact two-dimensional numerical solution for waves generated by a moving boundary

    7.3 Tsunami sources and travel across the ocean

         7.3.1 Sources

         7.3.2 Directional characteristics

         7.3.3 Travel across the ocean

    7.4 Effects along the coast

         7.4.1 Refraction

         7.4.2 Wave trapping

         7.4.3 Mach reflection

         7.4.4 Resonance

         7.4.5 Run-up and draw-down

    7.5 Distribution functions

         7.5.1 Entrance to San Francisco Bay, California, and other locations

         7.5.2 Risk

    7.6 Combined tide and tsunami probabilities

    References

Chapter 8 Structural Response to Earthquakes

    8.1 Introduction

    8.2 Common ground-motion representations

         8.2.1 Response spectra

         8.2.2 Simulated earthquakes

         8.2.3 Spectral-density functions

    8.3 Random vibration-based prediction of response spectra

         8.3.1 Stationary response variance

         8.3.2 Transient response variance

         8.3.3 Other pertinent response statistics

         8.3.4 Prediction of maximum response

         8.3.5 Compatibility of ground-motion representations

    8.4 Multi-degree-of-freedom systems

         8.4.1 Response-spectrum approach

         8.4.2 Random vibration approach

         8.4.3 Time-integration analysis

    8.5 Light secondary systems

         8.5.1 A response spectrum-based method

         8.5.2 Random vibration approach

         8.5.3 Time-integration method

    8.6 Inelastic systems

         8.6.1 Inelastic response spectra

         8.6.2 A probabilistic model

         8.6.3 Time-integration analysis

    Acknowledgements

    References

Chapter 9 Design

    9.1 Analysis of total risk

    9.2 Analysis of total risk: two-state systems

    9.3 Analysis of total risk: multiple damage states

    9.4 Analysis of total risk: distributed targets

    9.5 Design for seismic risk: optimization of an individual project

    9.6 Design for seismic risk: structural building codes

    9.7 Design for seismic hazard: lifelines

         9.7.1 Possible performance criteria

         9.7.2 Modeling of lifeline systems

    References

Chapter 10 Seismological Instrumentation

    10.1 Introduction

    10.2 Applications

    10.3 Requirements: General

    10.4 Peak-reading instruments

         10.4.1 Peak ground motion

         10.4.2 Peak structural motion

         10.4.3 Peak structural deformations

    10.5 Conventional seismographic systems — Design considerations

         10.5.1 Basic design parameters

         10.5.2 Bandwidth

         10.5.3 Sensitivity

         10.5.4 Response curve

         10.5.5 Setting specifications

         10.5.6 Peripheral considerations

    10.6 Conventional seismographic systems — Component elements

         10.6.1 General constraints

         10.6.2 The complete seismograph

         10.6.3 Seismometers

         10.6.4 Signal conditioning

         10.6.5 Recording

         10.6.6 Timing

         10.6.7 Telemetry

    10.7 Calibration

    References

Index