FprEN 1991-1-9

SLOVENSKI STANDARD
01-maj-2023
Evrokod 1 - Vplivi na konstrukcije - 1-9. del: Splošni vplivi - Atmosferska
zaledenitev
Eurocode 1 - Actions on structures - Part 1-9: General actions - Atmospheric icing
Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-9: Allgemeine Einwirkungen -
Atmosphärische Eisbildung
Eurocode 1 - Actions sur les structures - Partie 1-9 : Givrage atmosphérique
Ta slovenski standard je istoveten z: prEN 1991-1-9
ICS:
91.010.30 Tehnični vidiki Technical aspects
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
prEN 1991-1-9
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2023
ICS 91.010.30
English Version
Eurocode 1 - Actions on structures - Part 1-9: General
actions - Atmospheric icing
Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-9:
Allgemeine Einwirkungen - Atmosphärische Eisbildung
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 250.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1991-1-9:2023 E
worldwide for CEN national Members.

prEN 1991-1-9:2023 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 8
1.1 Scope of EN 1991-1-9 . 8
1.2 Assumptions . 8
2 Normative references . 8
3 Terms, definitions and symbols . 9
3.1 Terms and definitions . 9
3.2 Symbols and abbreviations . 10
3.2.1 Latin upper case letters . 10
3.2.2 Latin lower case letters . 11
3.2.3 Greek lower-case letters . 11
4 Design situations . 11
5 Classification of actions . 11
6 Ice load on structures . 12
6.1 Basic values . 12
6.2 Ice classes and characteristic values of glaze and rime . 13
6.3 Glaze . 13
6.4 Rime . 14
6.4.1 General. 14
6.4.2 Rime on single members . 14
6.4.3 Direction of ice vanes on the structure . 16
6.4.4 Rime on lattice structures . 17
6.5 Variation with height above the ground . 17
7 Combination of ice loads with other actions . 18
7.1 General. 18
7.2 Supplementary provisions for combination of ice and wind actions . 19
Annex A (informative) Falling ice considerations . 20
A.1 Use of this Informative Annex . 20
A.2 Scope and field of application . 20
A.3 Impact of falling ice . 20
Annex B (informative) Information on how ice loads acts on structures . 21
B.1 Use of this Informative Annex . 21
B.2 Scope and field of application . 21
B.3 General considerations . 21
B.4 Glaze on lattice structures . 21
B.5 Rime icing on members inclined to the wind direction . 22
B.6 Wet snow . 22
prEN 1991-1-9:2023 (E)
B.7 Unbalanced ice load . 23
Annex C (informative) Types of icing and data collection . 24
C.1 Use of this Informative Annex . 24
C.2 Scope and field of application . 24
C.3 Icing types . 24
C.4 Data Collection . 26
Annex D (informative) Guidance how to use EN 1991-1-9 . 28
Bibliography . 29
prEN 1991-1-9:2023 (E)
European foreword
This document (prEN 1991-1-9:2023) has been prepared by Technical Committee CEN/TC 250
“Structural Eurocodes”, the secretariat of which is held by BSI.
CEN/TC 250 is responsible for all Structural Eurocodes and has been assigned responsibility for
structural and geotechnical design matters by CEN.
This document is currently submitted to the CEN Enquiry.
This document is a new part of EN 1991-1.
The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part
of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to
CEN by the European Commission and the European Free Trade Association.
The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product,
and test standards, and to identify requirements for execution, materials, products and testing that are
relied upon by the Eurocodes.
The Eurocodes recognize the responsibility of each Member State and have safeguarded their right to
determine values related to regulatory safety matters at national level through the use of National
Annexes.
prEN 1991-1-9:2023 (E)
Introduction
0.1 Introduction to the Eurocodes
The structural Eurocodes comprise the following standards generally consisting of a number of Parts:
— EN 1990, Eurocode: Basis of structural and geotechnical design
— EN 1991, Eurocode 1: Actions on structures
— EN 1992, Eurocode 2: Design of concrete structures
— EN 1993, Eurocode 3: Design of steel structures
— EN 1994, Eurocode 4: Design of composite steel and concrete structure
— EN 1995, Eurocode 5: Design of timber structures
— EN 1996, Eurocode 6: Design of masonry structures
— EN 1997, Eurocode 7: Geotechnical design
— EN 1998, Eurocode 8: Design of structures for earthquake resistance
— EN 1999, Eurocode 9: Design of aluminium structures
— < New parts >
The Eurocodes are intended for use by designers, clients, manufacturers, constructors, relevant
authorities (in exercising their duties in accordance with national or international regulations),
educators, software developers, and committees drafting standards for related product, testing and
execution standards.
NOTE Some aspects of design are most appropriately specified by relevant authorities or, where not
specified, can be agreed on a project-specific basis between relevant parties such as designers and clients. The
Eurocodes identify such aspects making explicit reference to relevant authorities and relevant parties.
0.2 Introduction to EN 1991
(1) EN 1991 provides the actions to be considered for the structural design of buildings, bridges and
other civil engineering works, or parts thereof, including temporary structures, in conjunction with
EN 1990 and the other Eurocodes.
(2) The actions on structures, including in some cases geotechnical structures in conjunction with
EN 1997 as appropriate, provided in EN 1991 are intended to be applied in conjunction with the other
Eurocodes for the verification of safety, serviceability and durability, as well as robustness of structures,
including the execution phase.
(3) The application of this document for the verifications mentioned in (2) follows the limit state
principle and is based on the partial factor method, unless explicitly prescribed differently.
(4) EN 1991 does not cover actions for structures in seismic regions, unless explicitly prescribed by
EN 1998. Provisions related to such requirements are given in EN 1998, which complements and is
consistent with EN 1991.
prEN 1991-1-9:2023 (E)
(5) EN 1991 is also applicable in the case of existing structures for their:
— structural assessment,
— design of repairs, improvements and alterations,
— assessment for changes of use.
NOTE In this case additional or amended provisions can be necessary.
(6) EN 1991 is also applicable to the design of structures where materials or actions outside the scope
of the other Eurocodes are involved.
NOTE In this case additional or amended provisions can be necessary.
0.3 Introduction to EN 1991-1-9
EN 1991-1-9 gives design guidance for actions due to atmospheric icing on structures and civil
engineering works.
EN 1991-1-9 is intended to be used with EN 1990, the other Parts of EN
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