TABLE OF CONTENTS. vii

Transcription

1 TABLE OF CONTENTS CHAPTER 1: INTRODUCTION Scope Screening Detailed Evaluation Retrofit Design Strategies Design Earthquakes, Ground Motions, and Performance Criteria for Seismic Screening, Evaluation and Retrofit Design Report Outline...4 CHAPTER 2: WALLS AND RETAINING STRUCTURES Introduction Classification of Wall Types Rigid Gravity and Semi-Gravity Walls Gravity Walls Semi-Gravity Walls Prefabricated Modular Gravity Walls Anchored Walls Mechanically Stabilized Earth (MSE) Walls Other Wall Types Screening General Screening Criteria Level Level Summary Anchored Walls MSE Walls Evaluation of Retaining Walls Information Required for Detailed Evaluation Wall Details (a) Gravity Walls (b) Concrete Cantilever Retaining Walls (Inverted T-Type) (c) Tied-Back Walls (d) MSE Walls Soil Properties Ground Motions Gravity and Semi-Gravity Walls External Forces Acting on Gravity or Semi-Gravity Retaining Walls Considering Seismic Loading (a) Seismic Lateral Pressure (Thrust) on Walls (b) Passive Restraint (c) Seismic Bearing Capacity...27 vii

2 External Stability of Gravity or Semi-Gravity Retaining Walls Considering Seismic Loading: Critical Acceleration k h for Loss of Equilibrium (a) Overturning Stability (Tilting) Moment Equilibrium (b) Bearing Capacity Failure - Vertical Equilibrium Structural Integrity of Gravity or Semi-Gravity Retaining Walls Considering Seismic Loading (a) Analysis of Wall Stem (b) Analysis of Footing Loss of Service of Essential Facilities (a) Secondary Screening Procedure for Assessing Vulnerability to Seismically Induced Permanent Deformation (b) Determination of Threshold Acceleration (c) Estimation of Seismically Induced Deformation Concrete Cantilever Walls (Inverted T Walls) Anchored Walls Secondary Screening Procedure for Anchored Walls Evaluation Procedure for Anchored Walls (a) Passive Toe Failure-Rotation About the Top (b) Anchor Failure - Rotation of Base MSE Walls Evaluation Procedure for MSE Walls for Collapse (a) Tension in Reinforcements (b) Connection Details (c) Seismic Analysis of Segmental Reinforced Walls and Toppling of the Wall Face Proximity of Structures to MSE Walls (a) External Sliding Stability (b) Pullout (c) Internal Sliding Stability (for SRWs and MCUs) (d) Bulging Shear Failure Design of Seismic Retrofit for Earth Retaining Structures Gravity and Semi-Gravity Walls Concrete Cantilever Walls - Structural Failure of the Wall Anchored Walls MSE Walls Screening, Seismic Evaluation and Design of Seismic Retrofit for a Retaining Wall...67 viii

3 CHAPTER 3: SLOPES, EMBANKMENTS, AND ROCKFALLS Introduction Classification Screening Procedures Preliminary Screening Procedures Supplemental Screening Criteria for Rockfalls Supplemental Criteria for Category III Liquefaction-Induced Landslides Evaluation Procedures Evaluation of Category I Landslides Evaluation of Category II Landslides Pseudo-Static Slope Stability Analysis Procedure (a) Necessary Data for Analysis (b) Analysis Procedure (c) Special Considerations for Rock Slopes Deformation Analysis Procedures (a) Yield Acceleration, k y (b) Peak Acceleration Induced Within the Sliding Mass, k max (c) Estimating Deformation, D Evaluation of Category III Landslides Retrofitting Procedures Rock Slopes Soil Slopes Example Problems CHAPTER 4: TUNNELS Introduction Tunnel Classification Bored Tunnels Bored Tunnels in Soft Ground Bored Tunnels in Rock Cut-and-Cover Tunnels Submerged Tubes Screening Guidelines Objective of Screening Stage Factors Influencing Tunnel Seismic Performance Seismic Hazard Geological Conditions Tunnel Design, Construction and Condition Screening Guidelines Screening Guidelines Applicable to All Types of Tunnels ix

4 Additional Screening Guidelines for Bored Tunnels Additional Screening Guidelines for Cut-and-Cover Tunnels Additional Screening Guidelines for Submerged Tubes Evaluation Procedures Evaluation for Ground Shaking General Broad Guidelines for Analyses for Ground Shaking Evaluation of Axial and Curvature Deformations Along the Longitudinal Tunnel Axis (a) Simplified Analyses/Closed Form Solutions (b) Numerical Analysis Evaluation of Deformations of Tunnel Cross Section (a) Simplified Analyses/Closed-Form Solutions (b) Numerical Analysis Evaluation for Fault Rupture General Assessing the Amount of Fault Displacement Analyzing Tunnels for Fault Displacement Evaluation for Landsliding or Liquefaction Retrofit Strategies Ground Shaking-Induced Failure Bored Tunnels (a) Tunnels in Rock (b) Tunnels in Soil/Soft Ground Cut-and-Cover Tunnels Submerged Tubes Junctions and Transitions Fault Displacement-Induced Failure Landsliding- and Liquefaction-Induced Failure Examples of Tunnel Screening, Evaluation and Retrofit Strategies CHAPTER 5: CULVERTS Introduction Classification of Culverts and Background Information Flexible Culverts Background and Design Philosophies Rigid Culverts Background and Design Philosophies Culvert Joints Bell and Spigot Joints Tongue and Groove, Keyed and Butt Joints Closure Bands and Couplings Continuous Joints Screening for Potential Seismic Damage x

5 5.3.1 Theoretical Concepts Related to Seismically Induced Culvert Damage Permanent Ground Failure Transient Ground Motion Empirical Observations of Seismically Induced Culvert Damage Embankment Penetration Lateral and Embankment Spreading Slumping of Fill and Landslides Surface Faulting Ground Shaking Summary of Culvert Screening Criteria Commentary on Screening Procedure Evaluation Techniques Permanent Ground Failure Embankment and Penetration Lateral and Embankment Spreading Slumping of Fills and Landslides Surface Faulting Transient Ground Motion Longitudinal Response of Culverts Due to Transient Ground Motion Transverse Response of Culvert Due to Transient Ground Motion Examples of Culvert Evaluation Under Transient Ground Motion Retrofitting Strategies Ground Remediation Remove and Replace Culvert Liners Cast-in-Place Liners Field Erected Metallic Liners Sliplining Joint Retrofit CHAPTER 6: ROADWAYS Introduction Classification Screening and Evaluation Guidelines Stable Embankments and Foundations Hazard Screen Compaction of Embankment and Foundation Materials Hazard xi

6 Screen Evaluation Liquefiable or Soft Embankment and Foundation Materials Hazard Screens for Liquefaction Hazard Evaluation Potentially Unstable Embankments, Foundations or Slopes Hazard Preliminary Screening and Detailed Evaluation of Slope Instability Active Faults Screens for Fault Rupture Hazard Evaluation Procedures Retrofit Strategies Passive Strategies Active Strategies Structural Approach Slabs (SAS) Use of Easily Repairable Pavement Sections Replacement of Inferior Pavement Structures Strengthen Foundations Beneath Roadway Grades Clear and Strengthen Side or Cut Slopes APPENDIX A: CHARACTERISTICS OF SURFACE WAVES A.1 Introduction A.2 Examples of Prominent Rayleigh Waves During Earthquakes A.3 Summary ACKNOWLEDGMENTS REFERENCES xii