EN 1991-1-4 -2005 Eurocode 1 – Part 1-4 General actions – Wind actions (TCEC0003)

EN 1991-1-4 -2005 Eurocode 1 – Part 1-4 General actions – Wind actions

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Section 1 General

1.1 Scope

1.2 Normative references

1.3 Assumptions

1.4 Distinction between Principles and Application Rules

1.5 Design assisted by testing and measurements

1.6 Definitions

1.7 Symbols

Section 2 Design situations

Section 3 Modelling of wind actions

3.1 Nature

3.2 Representations of wind actions

3.3 Classification of wind actions

3.4 Characteristic values

3.5 Models

Section 4 Wind velocity and velocity pressure

4.1 Basis for calculation

4.2 Basic values

4.3 Mean wind

4.3.1 Variation with height

4.3.2 Terrain roughness

4.3.3 Terrain orography

4.3.4 Large and considerably higher neighbouring structures

4.3.5 Closely spaced buildings and obstacles

4.4 Wind turbulence

4.5 Peak velocity pressure

Section 5 Wind actions

5.1 General

5.2 Wind pressure on surfaces

5.3 Wind forces

Section 6 Structural factor cscd

6.1 General

6.2 Determination of cscd

6.3 Detailed procedure

6.3.1 Structural factor CsCd

6.3.2 Serviceability assessments

6.3.3 Wake buffeting

Section 7 Pressure and force coefficients

7.1 General

7.1.1 Choice of aerodynamic coefficient

7.1.2 Asymmetric and counteracting pressures and forces

7.1.3 Effects of ice and snow

7.2 Pressure coefficients for buildings

7.2.1 General

7.2.2 Vertical walls of rectangular plan buildings

7.2.3 Flat roofs

7.2.4 Monopitch roofs

7.2.5 Duopitch roofs

7.2.6 Hipped roofs

7.2.7 Multispan roofs

7.2.8 Vaulted roofs and domes

7.2.9 Internal pressure

7.2.10 Pressure on walls or roofs with more than one skin

7.3 Canopy roofs

7.4 Free-standing walls, parapets, fences and signboards

7.4.1 Free-standing walls and parapets

7.4.2 Shelter factors for walls and fences

7.4.3 Signboards

7.5 Friction coefficients

7.6 Structural elements with rectangular sections

7.7 Structural elements with sharp edged section

7.8 Structural elements with regular polygonal section

7.9 Circular cylinders

7.9.1 External pressure coefficients

7.9.2 Force coefficients

7.9.3 Force coefficients for vertical cylinders in a row arrangement

7.10 Spheres

7.11 Lattice structures and scaffoldings

7.12 Flags

7.13 Effective slenderness A and end-effect factor fJlJ.

Section 8 Wind actions on bridges

8.1 General

8.2 Choice of the response calculation procedure

8.3 Force coefficients

8.3.1 Force coefficients in x-direction (general method)

8.3.2 Force in x-direction – Simplified Method

8.3.3 Wind forces on bridge decks in z-direction

8.3.4 Wind forces on bridge decks in y-direction

8.4 Bridge piers

8.4.1 Wind directions and design situations

8.4.2 Wind effects on piers

Annex A (informative) Terrain effects

A.1 Illustrations of the upper roughness of each terrain category

A.2 Transition between roughness categories 0, I, II, III and IV

A.3 Numerical calculation of orography coefficients

A.4 Neighbouring structures

A.5 Displacement height

Annex B (informative) Procedure 1 for determining the structural factor CsCd

B.1 Wind turbulence

B.2 Structural factor

B.3 Number of loads for dynamic response

B.4 Service displacement and accelerations for serviceability assessments of a vertical structure

Annex C (informative) Procedure 2 for determining the structural factor CsCd

C.1 Wind turbulence

C.2 Structural factor

C.3 Number of loads for dynamic response

C.4 Service displacement and accelerations for serviceability assessments

Annex D (informative) CsCd values for different types of structures

Annex E (informative) Vortex shedding and aeroelastic instabilities

E.1 Vortex shedding

E.1.1 General

E.1.2 Criteria for vortex shedding

E.1.3 Basic parameters for vortex shedding

E.1.4 Vortex shedding action

E.1.5 Calcu lation of the cross wind amplitude

E.1.6 Measures against vortex induced vibrations

E.2 Galloping

E.2.1 General

E.2.2 Onset wind velocity

E.2.3 Classical galloping of coupled cylinders

E.3 Interference galloping of two or more free standing cylinders

E.4 Divergence and Flutter

E.4.1 General

E.4.2 Criteria for plate-like structures

E.4.3 Divergency velocity

Annex F (informative) Dynamic characteristics of structures

F.1 General

F.2 Fundamental frequency

F.3 Fundamental mode shape

F.4 Equivalent mass

F.5 logarithmic decrement of damping

Bibliography

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