Manual for the seismic design of steel and concrete buildings to Eurocode 8 (KEBT0013)

Manual for the seismic design of steel and concrete buildings to Eurocode 8, CONTENTS:      

1 Aim and scope

1.1 Aim

1.2 The Eurocode system

1.3 Scope of Manual

1.3.1 General

1.3.2 Basis of the Manual

1.3.3 Other general requirements

1.3.4 Other exclusions from the scope of this Manual

1.4 Contents

2 Reference documents

2.1 Other Eurocodes 8

2.2 National Forewords and Annexes

2.3 AFNOR and BSI supporting documentation

2.4 Other Eurocode manuals

2.5 Other sources of information

2.5.1 Designers’ guides to the Eurocodes

2.5.2 Websites

2.5.3 AFPS guides

3 National Annexes and Nationally Determined Parameters

3.1 Purpose of the National Annexes 11

3.2 Treatment of Nationally Determined Parameters 11

3.3 French National Annexes 11

3.4 UK National Annexes 12

4 Performance objectives

4.1 Introduction 13

4.2 No collapse requirement 13

4.3 Damage limitation requirement 14

5 Design fundamentals

5.1 Desirable characteristics of earthquake resistant buildings 15

5.2 Primary and secondary elements 16

5.3 Dissipative structures and zones 16

5.4 The behaviour factor q 16

5.5 Ductility classes 17

5.6 Capacity design method 19

5.7 Flow charts of the design process 20

6 Regularity in plan and elevation

6.1 Introduction 23

6.2 Consequences of regularity classification 24

6.3 Assessment of regularity in plan 25

6.3.1 Introduction 25

6.3.2 Preliminary assessment of regularity in plan 25

6.3.3 Detailed assessment of regularity in plan 28

6.3.4 Moderate irregularity in plan 31

6.3.5 High irregularity in plan 32

6.3.6 Determining the centres of stiffness, radii of gyration and torsional radii 32

6.4 Assessment of regularity in elevation 34

6.4.1 Regular elevations 34

6.4.2 Moderately irregular elevations 36

6.4.3 Highly irregular elevations 36

7 Geotechnical aspects

7.1 Influence of site conditions on seismic design 38

7.1.1 Principal hazards 38

7.1.2 Active faults 38

7.1.3 Slope stability 39

7.1.4 Topographical effects 40

7.1.5 Potentially liquefiable soils 40

7.1.6 Settlement of soils 43

7.2 Site investigation 43

7.2.1 Strength parameters 43

7.2.2 Determination of ground type 44

7.2.3 Soil stiffness and damping 44

8 Design ground motions

8.1 Introduction 47

8.2 Importance classes 51

8.3 Ground type 52

8.4 Horizontal elastic response spectrum 54

8.5 Horizontal design spectra 57

8.6 Near source effects 57

9 Seismic analysis

9.1 Choice of analysis method 58

9.2 General assumptions for seismic analysis 60

9.2.1 Modelling 60

9.2.2 Mass to be included in the seismic analysis 62

9.2.3 Torsion 64

9.2.4 Combination of the effects of the horizontal seismic components 66

9.2.5 Combinations of seismic loads with other loads 66

9.3 Equivalent linear analysis, using a q (behaviour) factor 67

9.3.1 Choice of linear analysis method 67

9.3.2 Use of planar models in buildings with irregularity in plan 68

9.3.3 Lateral force method 69

9.3.4 Modal combinations in multimodal response spectrum analysis 72

9.3.5 Calculation of displacement 73

9.4 Non-linear methods 74

9.4.1 Introduction 74

9.4.2 Modelling issues 74

9.4.3 Safety verification 75

9.4.4 Non-linear static (pushover) analysis 75

9.5 P-D effects 77

10 Concrete buildings

10.1 Overview of main differences between seismic and non-seismic design 79

10.2 Design to Eurocode 2 (DCL design) 79

10.3 Ductile design (DCM and DCH design) 80

10.4 Design strength of materials 80

10.4.1 Material properties 80

10.4.2 Partial factors for material properties 80

10.5 Types of reinforced concrete buildings and behaviour factors 81

10.6 Moment resisting frames (beams, columns and joints) 83

10.6.1 General conditions for frames 83

10.6.2. Columns 84

10.6.3 Beams 95

10.6.4 Beam-column joints 101

10.7 Walls 104

10.7.1 Definitions 104

10.7.2 Dimensions 104

10.7.3 Ductile walls and coupled walls 104

10.7.4 Large lightly reinforced walls 112

10.7.5 Further information on reinforced concrete wall design 117

10.8 Detailing of confinement reinforcement 117

10.9 Laps and splices 118

10.10 Design and detailing of secondary elements 119

10.11 Provisions for concrete floor diaphragms 120

10.12 Local effects due to masonry or concrete infills 121

10.13 Precast frames and precast floor systems 124

10.13.1 Introduction 124

10.13.2 Precast frames 124

10.13.3 Precast concrete floors 127

11 Steel buildings

11.1 Scope 129

11.2 Material specification 129

11.2.1 Material properties 129

11.2.2 Partial factors for materials 131

11.3 Design to Eurocode 3 (DCL Design) 132

11.4 Ductile Design (DCM and DCH Design) 132

11.5 Types of steel buildings and behaviour factors 135

11.5.1 Moment resisting frames 135

11.5.2 Concentrically braced frames 135

11.5.3 Behaviour factors 135

11.6 Requirements for compactness of sections in dissipative zones 138

11.7 General rules for connection design 138

11.8 Moment resisting frames (beams, columns and joints) 140

11.8.1 General 140

11.8.2 Dissipative regions 140

11.8.3 Beams 140

11.8.4 Connections 142

11.8.5 Columns 145

11.8.6 Web panels 147

11.9 Design of concentrically braced frames 148

11.9.1 General 148

11.9.2 Distribution of bracing strength 148

11.9.3 Columns and beams 149

11.9.4 Connections 149

11.9.5 Additional rules for specific types of concentrically braced frames 149

11.10 Unbraced frames with masonry infill 153

12 Foundations

12.1 General principles 154

12.2 Capacity design of foundations 154

12.3 Seismic capacity for shallow foundations 155

12.3.1 Ultimate limit state conditions 155

12.3.2 Sliding 156

12.3.3 Bearing capacity 157

12.4 Structural design of shallow concrete foundations 157

12.4.1 Design actions effects 157

12.4.2 Tie beams and foundation beams 158

12.5 Design of piled foundations 159

12.5.1 Seismic analysis 159

12.5.2 Design and detailing 161

13 Seismic joints

14 Damage limitation

15 Non-structural elements

15.1 General considerations 165

15.2 Protection of acceleration-sensitive non-structural elements 165

15.2.1 Introduction 165

15.2.2 Simplified procedure 165

15.2.3 Seismic coefficient 166

15.2.4 Importance factors 167

15.2.5 Behaviour factors 167

15.3 Protection of drift-sensitive non-structural elements 168

15.3.1 General 168

15.3.2 Masonry infill in contact with concrete and steel moment resisting frames 169