Title
Earthquake Resistant Design of Structures
Copyright
Dedication
Contents
Preface
Contributors
1. Engineering Seismology
1.1 Introduction
1.2 Reidβs Elastic Rebound Theory
1.3 Theory of Plate Tectonics
1.3.1 Lithospheric Plates
1.3.2 Plate Margins and Earthquake Occurrences
1.3.3 The Movement of Indian Plate
1.4 Seismic Waves
1.4.1 Body Waves
1.4.2 Surface Waves
1.5 Earthquake Size
1.5.1 Intensity
1.5.2 Isoseismal Map
1.5.3 Earthquake Magnitude
1.5.4 Energy Released in an Earthquake
1.5.5 Earthquake Frequency
1.6 Local Site Effects
1.6.1 Basin/Soil Effects
1.6.2 Lateral Discontinuity Effects
1.6.3 Effect of the Surface Topography
1.7 Internal Structure of the Earth
1.7.1 Crust
1.7.2 Upper Mantle
1.7.3 Lower Mantle
1.7.4 Core
1.8 Seismotectonics of India
1.9 Seismicity of India
1.10 Classification of Earthquakes
1.11 Tsunami
1.11.1 Tsunami Velocity
1.11.2 Run-up and Inundation
Summary
Glossary of Earthquake/Seismology
References
2. Seismic Zoning Map of India
2.1 Introduction
2.2 Seismic Hazard Map
2.3 Seismic Zone Map of 1962
2.4 Seismic Zone Map of 1966
2.4.1 Grade Enhancement
2.4.2 Review of Tectonic
2.5 Seismic Zone Map of 1970
2.6 Seismic Zone Map of 2002
2.7 Epilogue
Summary
References
3. Strong Motion Studies in India
3.1 Introduction
3.2 Understanding the Nature of Ground Motions
3.2.1 Source Effect
3.2.2 Path Effect
3.2.3 Site Effect
3.3 Estimation of Ground Motion Parameters
3.4 The Indian Perspective
3.5 Utilization of Strong Motion Data
Summary
References
4. Strong Motion Characteristics
4.1 Introduction
4.2 Terminology of Strong Motion Seismology
4.2.1 Amplitude Parameters
4.2.2 Duration of Strong Motion
4.2.3 Fourier Spectrum
4.2.4 Power Spectrum
4.2.5 Response Spectrum
4.2.6 Seismic Demand Diagrams
4.2.7 Spatial Variation of Earthquake Ground Motion
4.2.8 Damage Potential of Earthquakes
Summary
References
5. Evaluation of Seismic Design Parameters
5.1 Introduction
5.2 Types of Earthquakes
5.2.1 Intensity
5.2.2 Magnitude
5.3 Fault Rupture Parameters
5.4 Earthquake Ground Motion Characteristics
5.4.1 Amplitude Properties
5.4.2 Duration
5.4.3 Effect of Distance
5.4.4 Ground Motion Level
5.4.5 Geographical, Geophysics and Geotechnical Data
5.5 Deterministic Approach
5.6 Probabilistic Approach
5.6.1 Example
5.7 Response Spectra
5.8 Design Spectrum
Summary
References
6. Initiation into Structural Dynamics
6.1 Introduction
6.2 Mathematical Modelling
Summary
References
7. Dynamics of Single Degree of Freedom Systems
7.1 Introduction
7.2 Free Vibration of Viscous-Damped SDOF Systems
7.2.1 Underdamped Case (z < 1
7.2.2 Critically-damped Case (z = 1
7.2.3 Overdamped Case (z > 1
7.3 Forced Vibrations of SDOF Systems
7.3.1 Response of SDOF Systems to Harmonic Excitations
7.3.2 Excitation by Base Motion
7.3.3 Response of SDOF Systems to a Finite Duration Excitation
7.3.4 Response of SDOF Systems to a Short Duration Impulse
7.3.5 Response of SDOF Systems to General Dynamic Excitation
7.4 Vibration Isolation
Summary
References
8. Theory of Seismic Pickups
8.1 Introduction
8.2 The Physics of Operation
8.3 Which Parameter to Measure
8.4 Seismometers
8.4.1 Displacement Pickups
8.4.2 Velocity Pickups
8.5 Accelerometers
8.5.1 Servo-accelerometers
8.5.2 Calibration of Accelerometers
Summary
References
9. Numerical Evaluation of Dynamic Response
9.1 Numerical Solution Based on Interpolation of Excitation
9.2 Numerical Solution Based on Approximation of Derivatives
9.3 Stability and Accuracy Considerations
Summary
References
10. Response Spectra
10.1 Introduction
10.2 Fourier Spectra
10.3 Response Spectra
10.3.1 Formulation
10.3.2 Solution: Initially at Rest
10.3.3 Solution: General Conditions
10.3.4 Smooth Spectrum
10.3.5 Seismic Demand Diagrams
Summary
References
11. Dynamics of Multi-Degree-of-Freedom Systems
11.1 Introduction
11.2 System Property Matrices
11.3 Dynamics of Two Degree of Freedom Systems
11.4 Free Vibration Analysis of MDOF Systems
11.4.1 Orthogonality Conditions
11.5 Determination of Fundamental Frequency
11.5.1 Rayleigh Quotient
11.5.2 Stodola Method
11.5.3 Converging to Higher Modes
11.6 Forced Vibration Analysis
11.6.1 Mode-superposition Method
11.6.2 Excitation by Support Motion
11.6.3 Mode Truncation
11.6.4 Static Correction for Higher Mode Response
11.7 Model Order Reduction in Structural Dynamics
11.8 Analysis for Multi-Support Excitation
11.9 SoilβStructure Interaction Effects
11.9.1 Dynamic Analysis including SSI Effects
Summary
References
12. Earthquake and Vibration Effect on Structures:
Basic Elements of Earthquake Resistant Design
12.1 Introduction
12.2 Static and Dynamic Equilibrium
12.3 Structural Modelling
12.3.1 Structural Models for Frame Building
12.4 Seismic Methods of Analysis
12.4.1 Code-based Procedure for Seismic Analysis
12.5 Seismic Design Methods
12.5.1 Code-based Methods for Seismic Design
12.6 Response Control Concepts
12.6.1 Earthquake Protective Systems
12.7 Seismic Evaluation and Retrofitting
12.7.1 Methods for Seismic Evaluation
12.7.2 Methods for Seismic Retrofitting
12.8 Seismic Test Methods
12.8.1 Methods for Seismic Testing
Summary
References
13. Identification of Seismic Damages in RC Buildings
during Bhuj Earthquake
13.1 Introduction
13.2 Reinforced Concrete Building Construction Practices
13.3 Identification of Damage in RC Buildings
13.3.1 Soft Storey Failure
13.3.2 Floating Columns
13.3.3 Plan and Mass Irregularity
13.3.4 Poor Quality of Construction Material and Corrosion of Reinforcement
13.3.5 Pounding of Buildings
13.3.6 Inconsistent Seismic Performance of Buildings
13.4 Damage to Structural Elements
13.5 Damage to Non-Structural Panel Elements
13.5.1 Damage to Infill Walls
13.5.2 Damage to Exterior Walls
13.6 Damage to Water Tank and Parapets
13.7 Damage to Vertical Circulation Systems
13.7.1 Damage to Staircase
13.7.2 Damage to Elevator
13.8 Effect of Earthquake on Code Designed Structures
13.9 Lessons Learnt from Damages of RC Buildings
Summary
References
14. Effect of Structural Irregularities on the Performance
of RC Buildings during Earthquakes
14.1 Introduction
14.2 Vertical Irregularities
14.2.1 Vertical Discontinuities in Load Path
14.2.2 Irregularity in Strength and Stiffness
14.2.3 Mass Irregularities
14.2.4 Vertical Geometric Irregularity
14.2.5 Proximity of Adjacent Buildings
14.3 Plan Configuration Problems
14.3.1 Torsion Irregularities
14.3.2 Re-entrant Corners
14.3.3 Non-parallel Systems
14.3.4 Diaphragm Discontinuity
14.4 Recommendations
Summary
References
15. Seismoresistant Building Architecture
15.1 Introduction
15.2 Lateral Load Resisting Systems
15.2.1 Moment Resisting Frame
15.2.2 Building with Shear Wall or Bearing Wall System
15.2.3 Building with Dual System
15.3 Building Configuration
15.3.1 Problems and Solutions
15.4 Building Characteristics
15.4.1 Mode Shapes and Fundamental Period
15.4.2 Building Frequency and Ground Period
15.4.3 Damping
15.4.4 Ductility
15.4.5 Seismic Weight
15.4.6 Hyperstaticity/Redundancy
15.4.7 Non-structural Elements
15.4.8 Foundation Soil/Liquefaction
15.4.9 Foundations
15.5 Quality of Construction and Materials
15.5.1 Quality of Concrete
15.5.2 Construction Joints
15.5.3 General Detailing Requirements
Summary
References
16. Code Based Procedure for Determination of Design
Lateral Loads
16.1 Introduction
16.2 Seismic Design Philosophy
16.3 Determination of Design Lateral Forces
16.3.1 Equivalent Lateral Force Procedure
16.3.2 Dynamic Analysis Procedure
Summary
References
17. Consideration of Infill Wall in Seismic Analysis of
RC Buildings
17.1 Introduction
17.2 Structural and Constructional Aspects of Infills
17.3 Failure Mechanism of Infilled Frame
17.4 Analysis of Infilled Frames
17.4.1 Equivalent Diagonal Strut
Summary
References
18. Step-by-Step Procedure for Seismic Analysis of a Fourstoreyed
RC Building as per IS 1893 (Part 1): 2002
18.1 Introduction
18.2 Equivalent Static Lateral Force Method
18.2.1 Step 1: Calculation of Lumped Masses to Various Floor Levels
18.2.2 Step 2: Determination of Fundamental Natural Period
18.2.3 Step 3: Determination of Design Base Shear
18.2.4 Step 4: Vertical Distribution of Base Shear
18.3 Response Spectrum Method
A: Frame without Considering the Stiffness of Infills
18.3.1 Step 1: Determination of Eigenvalues and Eigenvectors
18.3.2 Step 2: Determination of Modal Participation Factors
18.3.3 Step 3: Determination of Modal Mass
18.3.4 Step 4: Determination of Lateral Force at Each Floor in Each Mode
18.3.5 Step 5: Determination of Storey Shear Forces in Each Mode
18.3.6 Step 6: Determination of Storey Shear Force due to All Modes
18.3.7 Step 7: Determination of Lateral Forces at Each Storey
B: Frame Considering the Stiffness of Infills
18.4 Time History Method
18.4.1 Step 1: Calculation of Modal Matrix
18.4.2 Step 2: Calculation of Effective Force Vector
18.4.3 Step 3: Calculation of Displacement Response in Normal Coordinate
18.4.4 Step 4: Displacement Response in Physical Coordinates
18.4.5 Step 5: Calculation of Effective Earthquake Response Forces at
Each Storey
18.4.6 Step 6: Calculation of Storey Shear
18.4.7 Step 7: Calculation of Maximum Response
Summary
References
Appendix 1: Linear Interpolation of Excitation
19. Mathematical Modelling of Multi-storeyed
RC Buildings
19.1 Introduction
19.2 Planar Models
19.2.1 Shear Beam Model
19.2.2 Flexure Beam Model
19.2.3 Idealized Plane Frame Model
19.2.4 Equivalent Shear Wall Frame Model
19.2.5 Plane Frame Model of Coupled Shear Walls
19.3 3D Space Frame Model
19.4 Reduced 3D Model
19.5 Some Important Issues in Modelling
19.5.1 Modelling of Floor Diaphragms
19.5.2 Modelling of Soil-Foundation
19.5.3 Foundation Models
19.5.4 Soil Models
19.5.5 Modelling of Staircases
19.5.6 Modelling of Infills
Summary
References
20. Ductility Considerations in Earthquake Resistant
Design of RC Buildings
20.1 Introduction
20.2 Impact of Ductility
20.3 Requirements for Ductility
20.4 Assessment of Ductility
20.4.1 Member/Element Ductility
20.4.2 Structural Ductility
20.5 Factors Affecting Ductility
20.6 Ductility Factors
20.7 Ductile Detailing Considerations as per IS 13920: 1993
Summary
References
21. Earthquake Resistant Design of a Four-storey
RC Building Based on IS 13920: 1993
21.1 Introduction
21.2 Preliminary Data for Example Frame
21.3 Loading Data
21.4 Analysis of Sub-frame 4-4
21.4.1 Dead Load Analysis
21.4.2 Live (Imposed) Load Analysis
21.4.3 Earthquake Load Analysis
21.5 Load Combinations
21.6 Design of Sub-Frame 4-4
21.6.1 Design of a Flexure Member
21.6.2 Design of Exterior Columns
21.6.3 Design of Interior Columns
21.6.4 Detailing of Reinforcements
Summary
References
22. Earthquake Resistant Design of Shear Wall as per
IS 13920: 1993
22.1 Introduction
22.2 Description of Building
22.3 Determination of Design Lateral Forces
22.4 Design of Shear Wall
22.5 Detailing of Reinforcements
Summary
References
23. Capacity Based DesignβAn Approach for Earthquake
Resistant Design of Soft Storey RC Buildings
23.1 Introduction
23.2 Preliminary Data for (G+3) Plane Frame
23.2.1 Determination of Loads
23.3 Step-by-Step Procedure for Capacity Based Design
23.3.1 Step 1: Seismic Analysis of Frame (G+3
23.3.2 Step 2: Determination of Flexural Capacity of Beams
23.3.3 Step 3: Establishing a Strong ColumnβWeak Beam Mechanism
23.3.4 Step 4: Determination of Moment Magnification Factors for Columns
23.3.5 Step 5: Capacity Design for Shear in Beams
23.3.6 Step 6: Capacity Design for Shear in Columns
23.3.7 Step 7: Detailing of Reinforcements
Summary
References
Appendix 1: Beam Flexural Capacity Calculation as per Design Aid IS456: 1978
Appendix 2: Determination of Moment Magnification Factor at Every Joint
24. Identification of Damages and Non-Damages in
Masonry Buildings from Past Indian Earthquakes
24.1 Introduction
24.2 Past Indian Earthquakes
24.3 Features of Damages and Non-damages
24.3.1 Bhuj Earthquake, January 26, 2001
24.3.2 Chamoli Earthquake, March 29, 1999
24.3.3 Jabalpur Earthquake, May 22, 1997
24.3.4 Killari Earthquake, September 30, 1993
24.3.5 Uttarkashi Earthquake, October 20, 1991
24.3.6 Bihar-Nepal Earthquake, August 21, 1988
24.4 Lessons Learnt
24.5 Recommendations
Summary
References
Appendix 1: Muzaffarabad Earthquake of October 8, 2005
25. Elastic Properties of Structural Masonry
25.1 Introduction
25.2 Materials for Masonry Construction
25.2.1 Unit
25.2.2 Mortar
25.2.3 Grout
25.2.4 Reinforcement
25.3 Elastic Properties of Masonry Assemblage
25.3.1 Compressive Strength
25.3.2 Flexural Tensile Strength
25.3.3 Shear Strength
Summary
References
26. Lateral Load Analysis of Masonry Buildings
26.1 Introduction
26.2 Procedure for Lateral Load Analysis of Masonry Buildings
26.2.1 Step 1: Determination of Lateral Loads
26.2.2 Step 2: Distribution of Lateral Forces
26.2.3 Step 3: Determination of Rigidity of Shear Wall
26.2.4 Step 4: Determination of Direct Shear Forces and Torsional
Shear Forces
26.2.5 Step 5: Determination of Increase in Axial Load Due to Overturning
26.2.6 Step 6: Walls Subjected to Out-of-plane Bending
Summary
References
27. Seismic Analysis and Design of Two-storeyed
Masonry Buildings
27.1 Introduction
27.2 Building Data
27.3 Step 1: Determination of Design Lateral Load
27.4 Step 2: Determination of Wall Rigidities
27.5 Step 3: Determination of Torsional Forces
27.6 Step 4: Determination Increase in Axial Load due to Overturning
27.7 Step 5: Determination of Pier Loads, Moments and Shear
27.8 Step 6: Design of Shear Walls for Axial Load and Moments
27.9 Step 7: Design of Shear Walls for Shear
27.10 Step 8: Structural Details
Summary
References
28. Seismic Evaluation of Reinforced Concrete Buildings:
A Practical Approach
28.1 Introduction
28.2 Components of Seismic Evaluation Methodology
28.2.1 Condition Assessment for Evaluation
28.2.2 Field Evaluation/Visual Inspection Method
28.2.3 Concrete Distress and Deterioration Other than Earthquake
28.2.4 Non-destructive Testing (NDT
Summary
References
29. Seismic Retrofitting Strategies of Reinforced
Concrete Buildings
29.1 Introduction
29.2 Consideration in Retrofitting of Structures
29.3 Source of Weakness in RC Frame Building
29.3.1 Structural Damage due to Discontinuous Load Path
29.3.2 Structural Damage due to Lack of Deformation
29.3.3 Quality of Workmanship and Materials
29.4 Classification of Retrofitting Techniques
29.5 Retrofitting Strategies for RC Buildings
29.5.1 Structural Level (or Global) Retrofit Methods
29.5.2 Member Level (or Local) Retrofit Methods
29.6 Comparative Analysis of Methods of Retrofitting
Summary
References
30. Seismic Retrofitting of Reinforced Concrete
BuildingsβCase Studies
30.1 Introduction
30.2 Methodology for Seismic Retrofitting of RC Buildings
30.3 Case Study 1: Seismic Retrofitting of RC Building with Jacketing and
Shear Walls
30.4 Case Study 2: Seismic Retrofitting of RC Building with Bracing and
Shear Wall
30.5 Case Study 3: Seismic Retrofitting of RC Building with Steel Bracing
30.6 Case Study 4: Seismic Retrofitting of RC Building by Jacketing of Frames
30.7 Case Study 5: Seismic Retrofitting of RC Building with Shear Walls and
Jacketing
30.8 Case Study 6: Seismic Retrofitting of RC Building by Adding Frames
30.9 Case Study 7: Seismic Retrofitting of RC Building by Steel Bracing and
Infill Walls
30.10 Case Study 8: Seismic Retrofitting of RC Building with Shear Walls
30.11 Case Study 9: Seismic Retrofitting of RC Building by Seismic Base Isolation
30.12 Case Study 10: Seismic Retrofitting of RC Building by Viscous Damper
Summary
References
31. Seismic Provisions for Improving the Performance of
Non-engineered Masonry Construction with
Experimental Verifications
31.1 Introduction
31.2 Criteria for Earthquake Resistant Provisions
31.3 Salient Features of Earthquake Resistant Provisions
31.4 Seismic Strengthening Features
31.5 Experimental Verification of Codal Provisions
31.5.1 Features of Model
31.5.2 Seismic Strengthening Arrangements
31.6 Shock Table Test on Structural Models
31.6.1 Behaviour of Models in Shock Tests
31.6.2 Recommendations
Summary
References
32. Retrofitting of Masonry Buildings
32.1 Introduction
32.2 Failure Mode of Masonry Buildings
32.2.1 Out-of-plane Failure
32.2.2 In-plane Failure
32.2.3 Diaphragm Failure
32.2.4 Failure of Connection
32.2.5 Non-structural Components
32.2.6 Pounding
32.3 Methods for Retrofitting of Masonry Buildings
32.3.1 Repair
32.3.2 Local/Member Retrofitting
32.3.3 Structural/Global Retrofitting
32.4 Repairing Techniques of Masonry
32.4.1 Masonry Cracking
32.4.2 Masonry Deterioration
32.5 Member Retrofitting
32.5.1 Retrofitting Techniques
32.6 Structural Level Retrofitting Methods
32.6.1 Retrofitting Techniques
32.7 Seismic Evaluation of Retrofitting Measures in Stone Masonry Models
32.7.1 Behaviour of Retrofitted Models
32.7.2 Findings
Summary
References
Index
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