1) EN 1991-1-4 gives guidance on the determination of natural wind actions for the structural design
of building and civil engineering works for each of the loaded areas under consideration. This includes
the whole structure or parts of the structure or elements attached to the structure, e. g. components,
cladding units and their fixings, safety and noise barriers.
This Part is applicable to:
(3) This part is intended to predict characteristic wind actions on land-based structures, their
components and appendages.
(4) Certain aspects necessary to determine wind actions on a structure are dependent on the location
and on the availability and quality of meteorological data, the type of terrain, etc. These need to be
provided in the National Annex and Annex A, through National choice by notes in the text as indicated.
Default values and methods are given in the main text, where the National Annex does not provide
information.
(5) Annex A gives illustrations of the terrain categories and provides rules for the effects of orography
including displacement height, roughness change, influence of landscape and influence of
neighbouring structures.
(6) Annex B and C give alternative procedures for calculating the structural factor cscd.
(7) Annex D gives cscd factors for different types of structures.
(8) Annex E gives rules for vortex induced response and some guidance on other aeroelastic effects.
(9) Annex F gives dynamic characteristics of structures with linear behaviour
(10) This part does not give guidance on local thermal effects on the characteristic wind, e.g. strong
arctic thermal surface inversion or funnelling or tornadoes.
? Buildings and civil engineering works with heights up to 200 m, see also (11).
? Bridges having no span greater than 200 m, provided that they satisfy the criteria for
dynamic response, see (12) and 8.2.
(11) Guyed masts and lattice towers are treated in EN 1993-3-1 and lighting columns in EN 40.
(12) This part does not give guidance on the following aspects:
? torsional vibrations, e.g. tall buildings with a central core
? bridge deck vibrations from transverse wind turbulence
? wind actions on cable supported bridges
? vibrations where more than the fundamental mode needs to be considered.
BS EN 1991-1-4-2005
EN 1991-1-4-2005 (E)