Structural Steel Design to SANS 10162:1- 2011

CONTENTS

MODULE 1 LOADING

1.1 INTRODUCTION 1.1

LOADING PATTERNS 1.2

1.1.1.1 Uniformly Distributed 1.2

1.1.1.2 Point.1.2

1.1.1.3 Triangular & Trapezoida 1.1.2

1.1.2 UNIT CONVERSIONS.1.4

1.1.2.1 Continuity Effects. 1.4

1.2 DEAD LOADS 1.5

1.2.1 GENERAL 1.5

1.2.2 MATERIAL DENSITY. 1.5

1.3 LIVE LOADS. 1.6

1.3.1 FLOOR LOADS 1.6

1.3.2 ROOF LOADS. 1.7

1.3.3 LOAD REDUCTION 1.7

1.4 WIND LOADS 1.8

1.4.1 INTRODUCTION.1.8

1.4.2 CHARACTERISTIC WIND SPEED.1.8

1.4.2.1 Regional basic wind speed 1.8

1.4.2.2 Terrain category 1.9

1.4.2.3 Local effects 1.10

1.4.2.4 Height above ground.1.10

1.4.2.5 Class of structure 1.11

1.4.2.6 Wind speed multiplier.1.11

1.4.3 VELOCITY PRESSURE 1.11

1.4.4 FORCES ON STRUCTURES 1.12

1.4.5 EXAMPLE 1.1 1.13

MODULE 2 LIMIT STATES DESIGN

& ANALYSIS

2.1 INTRODUCTION 2 1

2.1.1 LIMIT STATES APPROACH 2.1

2.1.1.1 Ultimate Limit State 2.1

2.1.1.2 Serviceability Limit State 2.1

2.1.1.3 Fatigue Limit State 2.1

2.2 LOAD AND RESISTANCE 2 2

2.2.1 PARTIAL FACTORS. 2.2

2.2.1.1 Load Factors 2.3

2.2.1.2 Load Combination Factors 2.3

2.2.1.3 Resistance Factors 2 3

2.2.2 LIMIT STATE EQUATION. 2.4

2.2.2.1 Consequence of failure. 2.5

2.2.3 ARRANGEMENT OF LOAD. 2.5

2.3 ANALYSIS. 2.8

2.3.1 SIMPLY-SUPPORTED BEAMS. 2.8

2.3.1.1 Span 2.9

2.3.1.2 Analysis 2.9

2.3.1.2.1 Shear force 2.9

2.3.1.2.2 Bending moment. 2.10

2.3.1.3 Example 2.1 (simply supported beam). 2.10

2.3.2 CONTINUOUS BEAMS 2.12

2.3.2.1 Span. 2.12

2.3.2.2 Methods of Analysis 2.10

2.3.2.2.1 Coefficient tables. 2.12

2.3.2.2.2 Example 2.2 (continuous beam). 2.14

2.3.3 PIN-JOINTED TRUSSES. 2.15

2.3.3.1 Stability and Determinacy. 2.15

2.3.3.2 Member Lengths 2.16

2.3.3.3 Methods of Analysis 2.17

2.3.3.3.1 Resolution of joints. 2.17

2.3.3.3.2 Method of sections. 2.17

2.3.3.3.3 Example 2.3 (pin-jointed truss) 2.18

2.3.3.4 Design Considerations 2.20

2.3.4 FRAMES. 2.21

2.3.4.1 Types of Construction 2.21

2.3.4.1.1 Rigid 2.21

2.3.4.1.2 Simple. 2.21

2.3.4.1.3 Semi-Rigid 2.21

2.3.4.2 Modes of Behaviour 2.22

2.3.4.3 Stability Effects. 2.22

2.3.4.3.1 Ultimate gravity moment. 2.22

2.3.4.3.2 Ultimate translational moment. 2.22

2.3.4.3.3 Amplification Factor. 2.23

2.3.4.5 Example 2.4 (rigid frame). 2.23

MODULE 3 CONNECTION DESIGN

3.1 BOLTED CONNECTIONS 3.1

3.1.1 SPACING REQUIREMENTS. 3.1

3.1.1.1 Pitch. 3.1

3.1.1.2 Edge Distance.3.1

3.1.1.3 End Distance 3.2

3.1.1.4 Gauges and Back-Marks.3.2

3.1.2 GENERAL INFORMATION.3.2

3.1.3 BEARING BOLTS 3.3

3.1.3.1 Bearing Resistance 3.3

3.1.3.1.1 Slotted holes 3.4

3.1.3.2 Shear 3.4

3.1.3.2.1 Long lap splices.3.5

3.1.3.3 Tension.3.6

3.1.3.4 Combined Shear and Tension.3.6

3.1.3.5 Bolt Strength Table (bearing bolts) 3.6

3.1.3.6 Example 3.1.3.7

3.1.4 FRICTION-GRIP BOLTS.3.8

3.1.4.1 Slip Resistance.3.8

3.1.4.2 Combined Shear and Tension.3.9

3.1.4.3 Bolt Strength Table (HSFG bolts).3.9

3.1.4.4 Example 3.2 3.9

3.1.5 ECCENTRIC CONNECTIONS.3.10

3.1.5.1 Shear and Tension.3.10

3.1.5.1.1 Example 3.3 (combined shear and tension).3.11

3.1.5.2 Shear and Torsion.3.12

3.1.5.2.1 Example 3.4 (shear and torsion).3.13

3.1.6 PRYING ACTION.3.14

3.2 WELDED CONNECTIONS.3 15

3.2.1 WELDING METHODS 3.15

3.2.2 WELD METAL STRENGTH.3.15

3.2.3 FILLET WELDS.3.16

3.2.3.1 Factored Resistance 3.16

3.2.3.2 Minimum Size.3.17

3.2.4 GROOVE WELDS.3.18

3.2.4.1 Factored Resistance 3.18

3.2.4.1.1 Shear 3.18

3.2.4.1.2 Tension normal to weld axis.3.19

3.2.5 ECCENTRIC CONNECTIONS.3.19

3.2.5.1 Shear and Torsion.3.19

3.2.5.2 Shear and Tension.3.21

3.3 COLUMN BASE PLATES 3.22

3.3.1 INTRODUCTION 3.22

3.3.2 COLUMN-TO-PLATE CONNECTION 3.22

3.3.3 PINNED SLAB BASE 3.23

3.3.3.1 Design equations 3.23

3.3.3.2 Example.3.26

3.3.4 FIXED SLAB BASE 3.27

3.3.4.1 Full compression.3.28

3.3.4.2 Tension in hold down bolts.3.28

MODULE 4 ELEMENT DESIGN

4.1 INTRODUCTION 4 1

4.1.1 SCOPE OF DESIGN. 4.1

4.1.2 GRADES OF STRUCTURAL STEEL. 4.1

4.1.3 LIMIT STATE DESIGN 4.1

4.2 AXIAL TENSION 4 4

4.2.1 SLENDERNESS LIMITS 4.2

4.2.2 RESISTANCE 4.2

4.2.2.1 Yielding Failure 4.2

4.2.2.2 Fracture Failure 4.3

4.2.2.2.1 Effective net area of bolted plates. 4.4

4.2.2.2.2 Effective net area of bolted sections. 4.5

4.2.2.2.2 Effective net area of welded sections 4.6

4.2.2.3 Tension and Shear Block Failure. 4.7

4.2.3 EXAMPLE 4.1 (bolted channel in tension). 4.8

4.2.4 EXAMPLE 4.2 (welded angle in tension). 4.10

4.3 AXIAL COMPRESSION. 4.12

4.3.1 LOCAL BUCKLING. 4.12

4.3.2 MEMBER BUCKLING. 4.14

4.3.2.1 Effective length. 4.14

4.3.2.1.1 Unrestrained length. 4.15

4.3.2.1.2 Effective length factor. 4.16

4.3.3 RESISTANCE OF SECTIONS OTHER THAN CLASS 4. 4.18

4.3.3.1 Flexural Buckling 4.18

4.3.3.1.1 Example 4.3 (doubly symmetric section) 4.19

4.3.3.2 Torsional or Torsional-Flexural Buckling 4.19

4.3.3.2.1 Example 4.4 (singly symmetric section). 4.23

4.3.3.2.2 Example 4.5 (asymmetric section). 4.25

4.3.4 RESISTANCE OF CLASS 4 SECTIONS. 4.27

4.3.4.1 Example 4.6 (class 4 section) 4.28

4.4 BENDING 4.30

4.4.1 CLASSIFICATION OF BEAMS 4.30

4.4.1.1 Beam Types 4.30

4.4.1.2 Class 4.31

4.4.2 BENDING THEORY. 4.32

4.4.2.1 Elastic Bending. 4.32

4.4.2.2 Plastic Bending. 4.34

4.4.3 BEAMS WITH CONTINUOUS LATERAL SUPPORT. 4.36

4.4.3.1 Resistance of classes 1, 2 and 3 4.36

4.4.3.2 Resistance of class 4. 4.36

4.4.3.3 Example 4.7 (restrained beam – class 1) 4.38

4.4.3.4 Example 4.8 (restrained beam – class 4) 4.38

4.4.4 LATERALLY UNSUPPORTED BEAMS 4.40

4.4.4.1 Lateral Restraint.4.40

4.4.4.2 Torsional Restraint.4.41

4.4.4.3 Effective Length.4.41

4.4.4.3.1 Simply supported beam 4.41

4.4.4.3.2 Cantilever beam 4.42

4.4.4.3.3 Beam Segments 4.43

4.4.4.4 Critical Elastic Moment 4.45

4.4.4.4.1 Doubly symmetric sections 4.45

4.4.4.4.2 Monosymmetric sections.4.46

4.4.4.5 Moment of Resistance 4.49

4.4.4.6 Example 4.9 (normal beam segment) 4.50

4.4.4.7 Example 4.10 (cantilever segment) 5.54

4 5 DEFLECTION.4.56

4.5.1 RECOMMENDED DEFLECTION.4.56

4 52 ACTUAL DEFLECTION.4.56

4.5.3 EXAMPLE 4.11.4.57

4 6 SHEAR.4.59

4.6.1 GENERAL.4.59

4.6.2 WEB SLENDERNESS.4.60

4.6.2.1 Shear Buckling Coefficient.4.61

4.6.3 ULTIMATE SHEAR STRESS 4.61

4.6.3.1 Critical plate-buckling stress 4.62

4.6.3.2 Tension field action.4.62

4.6.4 CONNECTING ELEMENTS.4.64

4.6.5 EXAMPLE 4.12 (unstiffened I-section).4.64

4.6.6 EXAMPLE 4.13 (stiffened plate girder).4.65

4.7 WEB STIFFENERS.4.67

4.7.1 BEARING STIFFENERS 4.67

4.7.1.1 Web yielding 4.67

4.7.1.2 Web crippling.4.68

4.7.1.3 Design requirements 4.68

4.7.1.4 Bearing 4.69

4.7.2 INTERMEDIATE STIFFENERS 4.70

4.7.2.1 General requirements.4.70

4.7.2.2 Design requirements 4.71

4.7.2.3 Connection to web.4.71

4.7.3 EXAMPLE 4.14. 4.72

4.8 COMBINED BENDING AND SHEAR 4.76

4.9 COMBINED BENDING AND COMPRESSION 4 77

4.9.1 ECCENTRICITY OF REACTIONS 4.77

4.9.2 SECOND-ORDER EFFECTS 4.78

4.9.3 CLASSIFICATION OF SECTION.4.80

4.9.4 RESISTANCE. 4.80

4.9.4.1 Class 1 and 2 I-sections 4.80

4.9.4.2 Class 3 and 4 I-sections 4.81

4.9.5 MODES OF FAILURE. 4.81

4.9.5.1 Cross-sectional strength 4.81

4.9.5.2 Overall member strength 4.82

4.9.5.3 Lateral torsional buckling strength. 4 82

4.9.6 EXAMPLE 4.15 4.83

4.10 AXIAL TENSION AND BENDING 4.87

4.10.1 RESISTANCE OF CLASS 1 AND 2 SECTIONS. 4.87

4.10.1.1 Cross-sectional strength 4.87

4.10.1.2 Lateral-torsional buckling 4.87

410.2 RESISTANCE OF CLASS 3 AND 4 SECTIONS. 4.87

4.10.2.1 Cross-sectional strength 4.87

4.10.2.2 Lateral-torsional buckling 4.88