DD ENV 1991-2.4 : 1997

Committees responsible
National foreword
National Application Document: Part A: Buildings
Introduction
1 Scope
2 References
3 Partial safety factors, combination factors and other
      values
4 Notation
5 Additional recommendations
Annex A (normative) Photographs/diagrams of terrain
                    categories
Annex B (normative) Treatment of transition between terrain
                    categories
Annex C (normative) Treatment of minimum height and effect
                    of obstructions
Annex D (normative) Directional pressure coefficients for
                    buildings
Annex E (normative) Wind structure incorporating the
                    principles of BS 6399: Part 2
Table B.1 - Values of transition factor
Table D.1 - Dynamic pressure, qref in Pa (N/m2)
Table D.2 - Internal pressure coefficients for enclosed
            buildings
Table D.3 - Internal pressure coefficients for buildings
            with dominant openings
Table D.4 - Internal pressure coefficients for open sided
            buildings
Table D.5 - External pressure coefficients for vertical
            walls of rectangular-plan buildings
Table D.6 - Reduction factors for Zone A on vertical walls
            of polygonal-plan buildings
Table D.7 - Pressure coefficients for vertical gable walls
            adjacent to non-vertical walls and roofs
Table A.8 - Pressure for windward-facing non-vertical walls
Table D.9 - External pressure coefficients for flat roofs
            with sharp eaves
Table D.10 - Reduction factor for Zones A to D of flat roofs
             with parapets
Table D.11 - External pressure coefficients for flat roofs
             with curved eaves
Table D.12 - External pressure coefficients for flat roofs
             with mansard eaves
Table D.13 - External pressure coefficients for pitched roof
             Zones A to J
Table D.14 - External pressure coefficients for pitched roof
             Zones K to S
Table D.15 - External pressure coefficients for pitched roof
             Zones U to Y of hipped roofs
Table D.16 - Reduction factor for multi-bay roofs
Figure 1 - United Kingdom - Wind map
Figure A.1 - Terrain category OzO = 0.003
Figure A.2 - Terrain category IzO = 0.01
Figure A.3 - Terrain category IIzO = 0.05
Figure A.4 - Terrain category IIIzO = 0.03
Figure A.5 - Terrain category IVzO = 1.0
Figure B.1 - Transition zones at change of roughness category
Figure B.2 - Determination of vm (z) after change of
             roughness
Figure B.3 - ce (z) values for transition from category 0 to
             category 1
Figure B.4 - ce (z) values for transition from category 1 to
             category 2
Figure B.5 - ce (z) values for transition from category 2 to
             category 3
Figure B.6 - ce (z) values for transition from category 3 to
             category 4
Figure B.7 - ce (z) values for transition from category 1 to
             category 3
Figure B.8 - ce (z) values for transition from category 1 to
             category 4
Figure C.1 - Effective heights
Figure D.1 - Wind directions for a rectangular-plan building
Figure D.2 - Size effect factor
Figure D.3 - Definition of diagonal of loaded areas
Figure D.4 - Key to global force Fw
Figure D.5 - Key for vertical walls of buildings
Figure D.6 - Key to vertical gable walls
Figure D.7 - Key for walls of buildings with re-entrant
             corners
Figure D.8 - Key for walls of buildings with recessed bays
Figure D.9 - Key to flush irregular walls
Figure D.10 - Key for walls of inset storey
Figure D.11 - Key to general method for flat roofs
Figure D.12 - Examples of zones of flat roof of arbitrary
              plan shape
Figure D.13 - Definitions of crosswind breadth, inwind depth
              and wide angle
Figure D.14 - Key to eave details for flat roofs
Figure D.15 - Additional zones around inset storey
Figure D.16 - Key to monopitch roofs
Figure D.17 - Symmetries for pitched roofs
Figure D.18 - Key for duopitch roofs
Figure D.19 - Key for hipped roofs
Figure D.20 - Key for mansard and multipitch roofs
Figure D.21 - Types of multi-bay roofs
Figure D.22 - Key to multi-bay roofs
List of references
National Application Document - Part B: Bridges
Contents
Foreword
Objectives of the Eurocodes
Background to the Eurocode Programme
Eurocode Programme
National Application Documents (NAD's)
Matters Specific to this Prestandard
1 General
      1.1 Scope
             1.1.1 Scope of ENV 1991-Eurocode 1
             1.1.2 Scope of ENV 1991-2-4 Wind Actions
             1.1.3 Further Parts of ENV 1991
      1.2 Normative references
      1.3 Distinction between principles and application
             rules
      1.4 Definitions
      1.5 Symbols
2 Classification of actions
3 Design situations
4 Representation of action
      4.1 Explanation of the wind actions and the response
             of the structures
      4.2 Modeling of wind actions
      4.3 Requirements for testing
5 Wind pressure on surface
      5.1 Field of application
      5.2 External pressure
      5.3 Internal pressure
      5.4 Net pressure
6 Wind forces
      6.1 Wind forces from pressures
      6.2 Friction force
7 Reference wind
      7.1 Reference wind pressure
      7.2 Reference wind velocity
      7.3 Annual probabilities of exceedence other than
             0.02
      7.4 Wind maps and meteorological information
8 Wind parameters
      8.1 Mean wind velocity
      8.2 Roughness coefficient
      8.3 Terrain categories
      8.4 Topography coefficient
      8.5 Exposure coefficient
9 Choice of procedures
      9.1 General
      9.2 Criteria for the Choice
      9.3 Dynamic coefficient for gust wind response
      9.4 Vortex shedding, aeroelastic instability and
             dynamic interference effects
             9.4.1 General
             9.4.2 Field of application
10 Aerodynamic coefficients
      10.1 General
      10.2 Buildings
             10.2.1 General
             10.2.2 Vertical walls of rectangular plan
                      buildings
             10.2.3 Flat roofs
             10.2.4 Duopitch roofs
             10.2.5 Hipped roofs
             10.2.6 Multispan roofs
             10.2.7 Vaulted roofs and domes
             10.2.8 Internal pressure
             10.2.9 Pressure on external walls or roofs with
                      more than one skin
      10.3 Canopy roofs
      10.4 Free-standing boundary walls, fences and
             signboards
             10.4.1 Solid boundary walls
             10.4.2 Pressure coefficients for porous fences
             10.4.3 Shelter factor for walls and fences
             10.4.4 Signboards
      10.5 Structural elements with rectangular sections
      10.6 Structural elements with sharp edged sections
      10.7 Structural elements with regular polygonal
             section
      10.8 Circular cylinders
             10.8.1 External pressure coefficients
             10.8.2 Force coefficients
      10.9 Spheres
      10.10 Lattice structures and scaffoldings
      10.11 Bridges
             10.11.1 General
             10.11.2 Force coefficients in x-direction
             10.11.3 Force coefficients in z-direction
             10.11.4 Longitudinal loads for bridges
      10.12 Flags
      10.13 Friction coefficients
      10.14 Effective slenderness l and slenderness
             reduction factor pl
Annex A (informative) Meterological information and national
                      wind maps
Annex B (informative) Detailed procedure for in-line response
Annex C (informative) Rules for vortex excitation and other
                      aeroelastic effects dynamic
                      characteristics

Gives information to enable ENV 1991-2-4: 1995 to be used for the design of building structures up to a height of 200 m, their appendages and components; cantilevered structures; highway and railway bridges up to 200 m span and for cycle track footbridges up to 30 m span. These structures are to be located in the UK or to be designed for UK loading.