Recent Advances in Earthquake Geotechnical Engineering and Microzonation (eBook)

PREFACE 7
TABLE OF CONTENTS 9
INTRODUCTION ROLE OF GEOTECHNICS IN EARTHQUAKE ENGINEERING 14
CHAPTER 1 MICROZONATION: DEVELOPMENTS AND APPLICATIONS 16
1.1. Introduction 16
1.2. The Structure of Probabilistic Seismic Hazard Analysis 17
1.3. Developments in Seismic Hazard Analysis 18
1.3.1. SEISMIC SOURCES 19
1.3.2. RECURRENCE RELATIONS 19
1.3.3. ATTENUATION RELATIONS 21
1.3.4. EFFECTS OF LOCAL SOIL CONDITIONS 23
1.3.5. NEHRP AMPLIFICATION FACTORS 26
1.4. Microzonation for Risk 27
1.5. Case History 30
1.5.1. BACKGROUND 30
1.5.2. VICTORIA RISK STUDY 31
1.6. Final Remarks 38
CHAPTER 2 THE INFLUENCE OF SCALE ON MICROZONATION AND IMPACT STUDIES 40
2.1. Part I – Earthquakes and the Impact on Societies 41
2.1.1. EARTHQUAKES IN THE WORLD AND IN EUROPE IN THE XXTH CENTURY 41
2.1.2. THE SOIL EFFECT ON THE CATASTROPHIC EVENTS 44
2.1.3. MITIGATION OF EARTHQUAKE RISK AND PREPAREDNESS 45
2.2. Part II – Definition of Problems and Techniques 46
2.2.1. SCENARIO STUDIES – GEOGRAPHIC SCALE OF INTERVENTION 46
2.2.2. SOIL INFORMATION 49
2.2.3. SPECTRAL SHAPES 52
2.3. Part III – Examples for Illustration 54
2.3.1. EXAMPLE 1. STUDIES AT THE COUNTRY LEVEL: PORTUGAL 54
2.3.2. EXAMPLE 2. STUDIES AT THE REGIONAL LEVEL: THE METROPOLITAN AREA OF LISBON (AML) 62
2.3.3. EXAMPLE 3. STUDIES AT THE COUNTY LEVEL: THE CASE OF LISBON 69
2.3.4. EXAMPLE 4. STUDIES AT THE BUILDING BLOCK LEVEL 76
2.4. Final Considerations and Future Developments 78
CHAPTER 3 STRONG GROUND MOTION 80
3.1. Introduction 80
3.2. Attenuation 80
3.3. Factors Affecting Earthquake Strong Ground Motions 86
3.3.1. EFFECTS OF THE EARTHQUAKE SOURCE 86
3.3.2. SUBDUCTION ZONE AND SHALLOW CRUSTAL EARTHQUAKES 88
3.3.3. EFFECTS OF DISTANCE 88
3.3.4. EFFECTS OF NEAR SURFACE WAVE PROPOGATION (SITE EFFECTS) 89
3.3.5. BASIN RESPONSE EFFECTS 90
3.4. Simple Earthquake Source Models 90
3.5. Time Domain Characteristics of Strong Ground Motion 94
3.5.1. MODELLING OF RMS-ACCELERATION 94
3.5.2. DURATION OF THE STRONG GROUND MOTION 96
3.6. Frequency Domain Characteristics of Strong Ground Motion 97
3.6.1. THEORETICAL MODEL OF FOURIER AMPLITUDE SPECTRUM 98
3.7. Radiation Pattern and Directivity 101
3.8. Simulation of Strong Ground Motion 105
3.8.1. STOCHASTIC SIMULATIONS 106
3.8.2. HYBRID SIMULATIONS 111
3.9. Conclusions 113
CHAPTER 4 GEOPHYSICAL AND GEOTECHNICAL INVESTIGATIONS FOR GROUND RESPONSE ANALYSES 114
4.1. Introduction 114
4.2. Mechanical Behaviour of Geomaterials 115
4.3. Laboratory Tests 119
4.3.1. TRIAXIAL TESTS 119
4.3.2. RESONANT COLUMN AND TORSIONAL SHEAR TEST 121
4.4. Field Tests 124
4.4.1. GEOPHYSICAL TESTS 124
4.4.2. IN SITU LARGE STRAIN TESTS: PRESSURIMETER AND PLATE LOAD TESTS 137
4.4.3. EMPIRICAL CORRELATIONS FROM PENETRATION TESTS 140
4.5. Case History 142
4.5.1. FIELD TESTS 143
4.5.2. LABORATORY TESTS 144
4.5.3. LABORATORY VS. FIELD TESTS 147
4.5.4. DEFINITION OF SOIL PARAMETERS FOR SEISMIC ANALYSIS 148
4.6. Conclusions 150
CHAPTER 5 SITE EFFECTS 152
5.1. Introduction 152
5.2. Basic Physical Concepts and Definitions 153
5.2.1. SITE EFFECTS DUE TO LOW STIFFNESS SURFACE SOIL LAYERS 155
5.3. Methods to Estimate Site Effects 159
5.3.1. EXPERIMENTAL-EMPIRICAL 159
5.3.2. EMPIRICAL METHODS 163
5.3.3. SEMI-EMPIRICAL METHODS 165
5.3.4. THEORETICAL (NUMERICAL AND ANALYTICAL) METHODS 166
5.3.5. CONCLUDING REMARKS 169
5.4. Site Effects in Horizontally Layered Soil Deposits 170
5.4.1. 1D SITE EFFECT COMPUTATIONS IN THE CITY OF THESSALONIKI 170
5.4.2. CONCLUSIVE REMARKS 176
5.5. 2D Phenomena in Ground Response Modelling 177
5.5.1. 2D EXPERIMENTAL AND THEORETICAL STUDIES IN EUROSEISTEST VALLEY 177
5.5.2. 2D EXPERIMENTAL AND THEORETICAL STUDIES IN THESSALONIKI 182
5.5.3. CONCLUSIVE REMARKS 187
5.6. Site Effects Due to Surface Topography 189
5.6.1. BRIEF LITERATURE REVIEW 189
5.6.2. SEISMIC CODES 191
5.6.3. THEORETICAL STUDIES IN AN EXPERIMENTAL SITE IN GREECE 191
5.6.4. CONCLUSIONS 200
5.7. Site Effects and Seismic Codes 201
5.7.1. THE CONCEPT OF EUROCODES 202
5.7.2. INTERNATIONAL BUILDING CODE 2000 202
5.7.3. SOIL AND SITE CLASSIFICATION 202
5.7.4. COMPATIBILITY OF DESIGN FORCES 206
5.7.5. SPECTRAL AMPLIFICATION 206
CHAPTER 6 EVALUATION OF LIQUEFACTION-INDUCED DEFORMATION OF STRUCTURES 212
6.1. Introduction 212
6.2. Design Procedures for Liquefaction 212
6.2.1. CURRENT DESIGN PROCEDURES 212
6.2.2. EFFECT OF THE 1995 KOBE EARTHQUAKE 213
6.2.3. LIQUEFACTION-INDUCED SETTLEMENT DURING THE 1999 KOCAELI EARTHQUAKE 216
6.3. Studies on Liquefaction-induced Deformation of Structures in Dense Sand or Silty Sand Grounds 219
6.3.1. NEW METHODS FOR THE PREDICTION OF THE OCCURRENCE OF LIQUEFACTION UNDER STRONG SHAKING 219
6.3.2. SOIL DENSITY AND SPT N-VALUE WHICH CAUSE LIQUEFACTION UNDER STRONG SHAKING 220
6.3.3. BEHAVIOUR OF STRUCTURES IN LIQUEFIED DENSE SANDY GROUND 222
6.3.4. BEHAVIOUR OF STRUCTURES IN LIQUEFIED SILTY GROUND 229
6.4. Evaluation Methods for Liquefaction-induced Deformation of Structures 231
6.4.1. RAFT FOUNDATIONS 231
6.4.2. PILE FOUNDATIONS 233
6.4.3. EMBANKMENTS 235
6.5. Countermeasures against Liquefaction-induced Damage of Structures 237
6.5.1. CURRENT COUNTERMEASURES 237
6.5.2. RECENT PROBLEMS 237
6.6. Liquefaction-induced Flow of the Ground 237
6.6.1. CONCEPT OF DESIGN METHOD 237
6.6.2. COUNTERMEASURES AGAINST THE FLOW 242
6.7. Concluding Remarks 242
CHAPTER 7 SEISMIC ZONATION METHODOLOGIES WITH PARTICULAR REFERENCE TO THE ITALIAN SITUATION 244
7.1. Introduction 244
7.2. Evaluation of the Expected Input Motion 247
7.2.1. DETERMINISTIC APPROACH 249
7.2.2. STOCHASTIC APPROACH 251
7.2.3. PROBABILISTIC APPROACH 254
7.2.4. DISCUSSION 256
7.3. Site Effects Evaluation 258
7.4. Final Remarks 263
CHAPTER 8 SEISMIC MICROZONATION: A CASE STUDY 266
8.1. Introduction 266
8.2. Regional Seismicity 267
8.3. Geological and Geotechnical Site Conditions 271
8.4. Earthquake Characteristics on the Ground Surface 274
8.5. Seismic Microzonation with Respect to Ground Shaking 277
8.6. Conclusions 278
CHAPTER 9 DYNAMIC ANALYSIS OF SOLID WASTE LANDFILLS AND LINING SYSTEMS 280
9.1. Introduction 280
9.2. Performance of Solid Waste Landfills during Earthquakes 280
9.3. Analysis of Solid Waste Landfills Stability during Earthquakes 281
9.3.1. INTRODUCTION 281
9.3.2. EXPERIMENTAL METHODS 281
9.3.3. MATHEMATICAL METHODS 282
9.3.4. SELECTION OF DESIGN EARTHQUAKES 283
9.3.5. SELECTION OF SOIL PROPERTIES FOR DYNAMIC ANALYSIS 285
9.3.6. SEISMIC RESPONSE ANALYSIS 290
9.3.7. LIQUEFACTION ASSESSMENT 295
9.4. Monitoring and Safety Control of Landfills 295
9.5. Safety and Risk Analyses 296
9.6. Final Remarks 297
CHAPTER 10 EARTHQUAKE RESISTANT DESIGN OF SHALLOW FOUNDATIONS 298
10.1. Introduction 298
10.2. Aseismic Foundation Design Process 298
10.3. Evaluation of Seismic Demand 299
10.3.1.FUNDAMENTALS OF SOIL STRUCTURE INTERACTION 299
10.3.2.CODE APPROACH TO SOIL STRUCTURE INTERACTION ANALYSES 301
10.3.3.IMPROVED EVALUATION OF SEISMIC DEMAND 303
10.4. Bearing Capacity for Shallow Foundations 307
10.4.1.FUNDAMENTAL REQUIREMENT OF CODE APPROACHES 308
10.4.2.THEORETICAL FRAMEWORK FOR THE PSEUDO-STATIC BEARING CAPACITY 309
10.5. Evaluation of Permanent Displacements 311
10.5.1.FURTHER DEVELOPMENTS: TOWARDS PERFORMANCE BASED DESIGN 312
10.6. Construction Detailing 313
10.7. Conclusions 314
CHAPTER 11 BEHAVIOUR AND DESIGN OF DEEP FOUNDATION SUBJECTED TO EARTHQUAKES 316
11.1. Introduction 316
11.2. Performance of Near-Surface Soils and Pile Foundations during the 1995 Hyogoken-Nambu Earthquake 317
11.2.1.SOIL LIQUEFACTION AND GROUND MOTION 317
11.2.2.CHARACTERISTICS OF PILE FOUNDATIONS OF BUILDINGS 318
11.2.3.PILE DAMAGE FROM DETAILED FIELD INVESTIGATION 320
11.3. Cyclic and Permanent Ground Displacements during Earthquakes 322
11.3.1.CYCLIC AND PERMANENT SHEAR STRAINS IN LIQUEFIED AND LATERALLY SPREADING GROUND 322
11.3.2.PERMANENT GROUND DISPLACEMENT NEAR WATERFRONT 324
11.4. Pseudo-Static Analysis for Seismic Design of Pile Foundations 325
11.4.1.INERTIAL AND KINEMATIC FORCES ACTING ON FOUNDATION 325
11.4.2.BEAM-ON-WINKLER-FOUNDATION METHOD 326
11.4.3.NON-LINEAR P-Y SPRING 327
11.4.4.EARTH PRESSURE ACTING EMBEDDED FOUNDATION 328
11.5. Effects of Cyclic Ground Displacements on Pile Performance 328
11.6. Effects of Permanent Ground Displacements on Pile Performance 332
11.7. Conclusions 337
REFERENCES 338
INDEX 366
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CHAPTER 1

MICROZONATION: DEVELOPMENTS AND APPLICATIONS (p.3-4)

W. D. Liam Finn, Kagawa University, Takamatsu, Japan Tuna Onur, Pacific Geoscience Centre, Sidney, BC, Canada Carlos E. Ventura, University of British Columbia, Vancouver BC, Canada


1.1. Introduction

Building codes base seismic design forces on various seismic hazard parameters that describe the intensity of ground shaking during an earthquake. The design parameter is typically acceleration, velocity or spectral acceleration with a specified probability of exceedance. These parameters are mapped on a national scale for a standard ground condition, usually rock or stiff soil. Mapping to such a scale is called macrozonation.

Damage patterns in past earthquakes show that soil conditions at a site may have a major effect on the level of ground shaking. Mapping of seismic hazard at local scales to incorporate the effects of local soil conditions is called microzonation for seismic hazard. The analysis for calculating the probability of exceeding different levels of the mapped ground motion parameter is called seismic hazard analysis. The basic structure of seismic hazard analysis is presented in this chapter and its evolution to the present state of the art will be described.

The presentation is geared to the user, not the analyst. It attempts to give the user a useful level of understanding of how the seismic hazard parameter of the microzonation is determined, what it means, what uncertainties are associated with it and how they are handled in the analysis. Microzonation for seismic hazard has many uses. It can provide input for seismic design, land use management, and estimation of the potential for liquefaction and landslides. It also provides the basis for estimating and mapping the potential damage to buildings. Mapping the losses expected from a particular level of seismic shaking is called microzonation for risk. The presentation of the procedures for microzonation for risk is also geared to the user.

The procedures for estimating losses for a selected probability of exceedance of ground shaking level will be explained and the entire process illustrated by means of a case history of loss estimation conducted for the insurance industry in Canada. Seismic hazard analysis, which is the major component of microzonation for seismic hazard and seismic risk, can be a very expensive and time consuming activity.

Therefore the objectives of the microzonation and how the results are likely to be used should be clearly understood by analyst and user before the levels of effort and sophistication of the hazard analysis are decided. The potential range in useful effort is exemplified by the following two examples. Hensolt and Brabb (1990) published a microzonation map of San Mateo County, California, showing the distribution of the site factors, S, in the Uniform Building Code.

These site factors define the amplification of ground motions by four different soil profiles compared to the motions in rock or stiff soils. Therefore the map, in effect, shows the relative seismic hazards at different locations in terms of S. In addition, if this map is overlaid on the basic hazard map for stiff ground, a revised map can be drawn that reflects in a significant way the effects of local soil conditions. Such a map is feasible in most metropolitan areas as the basic soil data is available from construction records. This represents a very basic, elementary, and affordable way of microzoning a metropolitan area for hazard, while taking into account local soil conditions.