Seismic Design of Building Structures

Transcription

1 Seismic Design of Building Structures A Professional's Introduction to Earthquake Forces and Design Details Ninth Edition Michael R. Lindeburg, PE with Kurt M. McMullin, PE '.The Power to Pass Professional Publications, Ine. Belmont, California

2 TABLE OF CONTENTS PREFACE ACKNOWLEDGMENTS HOW TO USE THIS BOOK CODES USED IN THIS BOOK NOMENCLATURE vii ix xi xv xvii 10 Vertical Acceleration Probability of Occurrence Frequency of Occurrence Attenuation of Ground Motion Seismometer Accelerometer Other Seismic Instruments Earthquake Prediction Other Earthquake Characteristics 16 1 BASIC SEISMOLOGY 1 The Nature of Earthquakes 1 2 Earthquake Terminology 1 3 Global Seismicity 2 4 Continental Drift Plate Tectonics 2 6 Submarine Ridges 3 7 Submarine Trenches 3 8 Earthquake Energy Release Seismic Sea Waves 4 10 Faults 4 11 California Faults 5 12 San Andreas Fault 5 13 Creep 7 14 Seismic Waves 7 15 Locating the Epicenter 8 2 EARTHQUAKE CHARACTERISTICS 1 Intensity Scale 9 2 Isoseismal Maps 10 3 Richter Magnitude Scale 10 4 Richter Magnitude Calculation 11 5 Energy Release and Magnitude Correlation 11 6 Length of Active Fault 12 7 Length of Fault Slip 12 8 Peak Ground Acceleration 12 9 Correlation of Intensity, Magnitude, and Acceleration with Damage 13 3 EFFECTS OF EARTHQUAKES ON STRUCTURES 1 Seismic Damage 17 2 Geographie Distribution of Seismic Risk 17 3 Risk Microzones Probable and Maximum Considered Earthquake Ground Motions 20 5 Effective Peak Ground Acceleration 20 6 Site Period Soil Liquefaction Building Period 21 9 Spectral Characteristics Seismic Force Relationship Between Spectral Values 21 4 VIBRATION THEORY 1 Two Approaches to Seismic Design 23 2 Simple Harmonie Motion 23 3 Stiffness and Flexibility 24 4 Rigidity 24 5 Natural Period and Frequency 25 6 Damping 27 7 Damping Ratio 28 8 Decay Envelope Damping Ratio of Buildings Damped Period of Vibration Forced Systems Magnification Factor 29

3 iv SEISMIC DESIGN OF BUILDING STRUCTURES 13 Resonancc Impulse Response~UndampedSystem Duhamel's Integral for an Undamped System Multiple-Degree-of-Freedom Systems Response of MDOF Systems Mode Shape Factors Rayleigh Method Participation Factor Story Shears 35 5 RESPONSE OF STRUCTURES 1 Elastic Response Spectra 37 2 Idealized Response Spectra 38 3 Response Spectra for Other Earthquakes 39 4 Log Tripartite Graphs 39 5 Ductility 40 6 Strain Encrgy and Ductility Factor 41 7 Hysteresis 41 8 Large Ductility Swings 41 9 Inelastic Response Spectra Normalized Design Response Spectra Response Spectrum for IBC-Defined Soil Profiles Drift P-6 Effect Torsional Shear Stress Negative Torsional Shear Overturning Moment Rigid Frame Buildings High-Rise Buildings 49 6 SEISMIC BUILDING CODES 1 Historical Basis of Seismic Codes in California 51 2 Seismic Codes International Building Code 54 4 Survivability Design Criteria 54 5 Effectiveness of Seismic Provisions 55 6 Applicable Seismic Sections in the IBC 55 7 Nature of IBC Seismic Code Provisions Wind Loads 56 9 Snow Loads Combined Seismic, Wind, and Snow Loading Seismic Design Criteria Selection IBC Procedure for Determining Design Acceleration Occupancy Categories Seismic Importance Factor: I Soil-Profile Types: Site Class A Through F Near Source Effects Seismic Response Coefficients Seismic Design Category Response Modification Factor: R Seismic System Overstrength Factor: no Structural Systems 64 A Bearing Wall Systems 64 B Building Frame Systems 64 C Moment-Resisting Frames D Dual Systems EInverted Pendulum Building Systems 65 F Shear Wall-Frame Interaction Systems 66 G Undefined Systems Redundancy Factor: p Regular/lrregular Structures Vertical Structural Irregularity Horizontal Structural Irregularity Building Period: T Earthquake Loads: E Load Combinations Total Seismic Dead Load: W Seismic Response Coefficient Lateral Force Procedures Static Lateral-Force Procedure When the IBC Permits a Static Analysis Simplified Lateral-Farce Procedure Vertical Distribution of Base Shear to Stories Simplified Vertical Distribution of Base Shear to Stories Provisions far Vertical Ground Acceleration Provisions for Direction of the Earthquake Provisions for Horizontal Torsional Moment Story Drift Determination Provisions for Building Separations Provisions for Overturning Moment Provisions far P-delta Effects Seismic Farce on Nonstructural Components Provisions far Ties and Continuity Nonbuilding Structures Provisions for Deformation Compatibility Penalties for Structural Irregularity Dynamic Analysis Procedure Allowable Stress Levels DIAPHRAGM THEORY 1 Diaphragm Action Seismic Wall and Diaphragm Forces Wall Shear Stress Rigid Diaphragm Action Calculating Wall Rigidity

4 TABLE OF CONTENTS v 6 Flexible Diaphragms Framing Tenninology Collectors Collector Force Colllrnns Supporting Parts of Flexible Diaphragrns Flexible Diaphragm Construction FIE~xiblc Diaphragm Torsion Diaphragm Shear Stress Diaphragm Flexure Deflection of Flexible Diaphragms Chords Chord Force Chord Size Overturning Moment GENERAL STRUCTURAL DESIGN 1 Distributing Story Shears to Members of Unknown Size Portal Method Cantilcver Method Spurr Method Frame Member Sizing DETAILS OF SEISMIC-RESISTANT CONCRETESTRUCTURES 1 Concretc Construction Details 129 A Orthogonal Effects 130 B Connections 130 C Deformation Compatibility 130 D Ties and Continllity E Collector Elements 130 F Concrete Frames G Anchorage to Concretc and Masonry Walls 131 H Boundary Elements of Shear Walls and Diaphragms 131 I Seismic Hooks, Crossties, and Hoops 131 J Strength Reduction Factors 131 K Combined Loading Load Factors 132 L Concrete Strength 132 M Steel Reinforcernent N Special Momcnt-Resisting Frame Flexural Mernbers o Top and Bottom Reinforcement P Temlion Lap Splices Q Welded Splices and Mechanical Connections 134 R Special Mornent-Resisting Frame Membcrs with Bending and Axial Loads 134 S Colurnns Carrying Discontinuous Walls 135 T Diaphragms 135 U Minimum Column Size 136 V Joints DETAILS OF SEISMIC-RESISTANT STEEL STRUCTURES 1 Steel Construction Details A Design and Construction Provisions B Seismic Provisions for Structural Steel Buildings 137 C Loads and Load Combinations 137 D Steel Frames 137 E Steel Properties 138 F Member Strength 138 G Column Requirements 138 H Ordinary Moment Frames 138 I Special Moment-Resisting Frames 139 J Special Truss Moment-Frames 139 K Welded and Bolted Connections 140 L Girder-Column Joint Restraints 141 M Braced Frames Eccentrically Braced Frames Steel Stud Wall Systems DETAILS OF SEISMIC-RESISTANT MASONRYSTRUCTURES 1 Masonry Structures 145 A Design and Construction Provisions B Seismic Provisions for Structural Masonry Buildings 145 C Loads and Load Combinations 145 D Masonry Construction Details 145 E Masonry Wall Frames 146 F Allowable Shear Stress DETAILS OF SEISMIC-RESISTANT WOOD STRUCTURES 1 Wood Structures 149 A Design and Construction Provisions 149 B Seismic Provisions for Structural Wood Buildings 149 C Loads and Load Combinations Wood Shear Wall and Wood Structural Panel Diaphragm Design Criteria 149 A Framing 150 B Wood Structural Panels 150 C Requirements for Resisting Horizontal Forces in Concrete/Masonry Buildings Wood Structural Panel Shear Walls Diaphragm and Shear Wall Aspect Ratios Wood Structural Panel Diaphragm Construction Details Bridging/Blocking Subdiaphragms

5 vi SEISMIC DESIGN OF BUILDING STRUCTURES 8 Connector Strengths A Nails 154 B Bolts 154 C Adjustment Factors Flexible Diaphragm to Wall Connection Details Cross-Grain Loading Framing for Diaphragm Openings Cripple Walls TILT-UP CONSTRUCTION SPECIAL DESIGN FEATURES 1 Energy Dissipation Systems Base Isolation Seismic-Isolated Design Details Damping Systems Architectural Considerations Upgrading Existing Construction PRACTICE PROBLEMS 1 Earthquakes in General Buildings Structural Systems !BC and ASCE/SEI Concrete and Masonry Structures Steel Structures Soils and Foundations Design Problems Qualitative Problems 199 APPENDICES A Conversion Factors 211 B Definitions 212 C Chronology of Important California Earthquakes 215 D Rigidity of Fixed Piers E Rigidity of Cantilever Piers F Accelerogram of 1940 EI Centro Earthquake (North-South Component) 219 G Seismic Acronyms and Abbreviations 220 H Design Coefficients and Factors for Seismic Force-Resisting Systems 221 I Standard Welding Symbols of the AISC/AWS 224 J Simpson Strong-Tie Structural Connectors: Holdowns and Tension Ties 225 K NDS Connections and Fasteners Tables 230 L Nail and Spike Reference Withdrawal Design Values (W) 235 M Bolts: Reference Lateral Design Values (Z) for Single Shear (Two Member) Connections for Sawn Lumber or SCL with Both Members of Identical Specific Gravity 236 N Bolts: Reference Lateral Design Values (Z) for Double Shear (Three Member) o Connections Bolts: Reference Lateral Design Values (Z) for Single Shear (Two Member) Connections for Sawn Lumber or SCL to Concrete 240 P 1994 Northridge Earthquake: Performance of Steel Moment Frame Connections INDEX 249 INDEX OF FIGURES AND TABLES 257 INDEX BY SEISMIC BUILDING CODE 261