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1、EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1991-1-2 November 2002 ICS 13.220.50; 91.010.30Supersedes ENV 1991-2-2:1995 English version Eurocode 1: Actions on structures - Part 1-2: General actions - Actions on structures exposed to fire Eurocode 1: Actions sur les structures au feu - Parti
2、e 1-2: Actions gnrales - Actions sur les structures exposes Eurocode 1 - Einwirkungen auf Tragwerke - Teil 1-2: Allgemeine Einwirkungen - Brandeinwirkungen auf Tragwerke This European Standard was approved by CEN on 1 September 2002. CEN members are bound to comply with the CEN/CENELEC Internal Regu
3、lations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This Eur
4、opean Standard exists 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 Management Centre has the same status as the official versions. CEN members are the natio
5、nal standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPIS
6、CHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2002 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1991-1-2:2002 E EN 1991-1-2:2002 (E) 2 Contentspage Foreword4 Section 1General .10 1.1Scope 10 1.2No
7、rmative references 10 1.3Assumptions 11 1.4Distinction between Principles and Application Rules. 11 1.5Terms and definitions 11 1.5.1Common terms used in Eurocode Fire parts . 11 1.5.2Special terms relating to design in general. 13 1.5.3Terms relating to thermal actions. 13 1.5.4Terms relating to he
8、at transfer analysis . 15 1.6Symbols. 15 Section 2Structural Fire design procedure21 2.1General 21 2.2Design fire scenario. 21 2.3Design fire . 21 2.4Temperature Analysis . 21 2.5Mechanical Analysis 22 Section 3Thermal actions for temperature analysis .23 3.1General rules. 23 3.2Nominal temperature-
9、time curves. 24 3.2.1Standard temperature-time curve. 24 3.2.2External fire curve. 24 3.2.3Hydrocarbon curve . 25 3.3Natural fire models 25 3.3.1Simplified fire models . 25 3.3.1.1General . 25 3.3.1.2Compartment fires 25 3.3.1.3Localised fires. 26 3.3.2Advanced fire models. 26 Section 4Mechanical ac
10、tions for structural analysis27 4.1General 27 4.2Simultaneity of actions. 27 4.2.1Actions from normal temperature design . 27 4.2.2Additional actions 28 4.3Combination rules for actions 28 4.3.1General rule 28 4.3.2Simplified rules. 28 4.3.3Load level . 29 Annex A (informative) Parametric temperatur
11、e-time curves30 Annex B (informative) Thermal actions for external members - Simplified calculation method33 B.1Scope 33 B.2Conditions of use. 33 EN 1991-1-2:2002 (E) 3 B.3Effects of wind. 34 B.3.1Mode of ventilation 34 B.3.2Flame deflection by wind 34 B.4Characteristics of fire and flames 35 B.4.1N
12、o forced draught. 35 B.4.2Forced draught. 37 B.5Overall configuration factors 39 Annex C (informative) Localised fires41 Annex D (informative) Advanced fire models44 D.1One-zone models 44 D.2Two-zone models 45 D.3Computational fluid dynamic models. 45 Annex E (informative) Fire load densities .46 E.
13、1General 46 E.2Determination of fire load densities. 47 E.2.1General. 47 E.2.2Definitions. 47 E.2.3Protected fire loads. 48 E.2.4Net calorific values . 48 E.2.5Fire load classification of occupancies. 50 E.2.6Individual assessment of fire load densities. 50 E.3Combustion behaviour 50 E.4Rate of heat
14、 release Q 51 Annex F (informative) Equivalent time of fire exposure.53 Annex G (informative) Configuration factor55 G.1General 55 G.2Shadow effects 56 G.3External members. 56 Bibliography 59 EN 1991-1-2:2002 (E) 4 Foreword This document (EN 1991-1-2:2002) has been prepared by Technical Committee CE
15、N/TC 250 “Structural Eurocodes“, the secretariat of which is held by BSI. CEN/TC250/SC1 is responsible for Eurocode 1. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2003, and conflicting nat
16、ional standards shall be withdrawn at the latest by December 2009. This document supersedes ENV 1991-2-2:1995. Annexes A, B, C, D, E, F and G are informative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement thi
17、s European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Background of the Eurocode programme In 1975, the Commission of the European
18、 Community decided on an action programme in the field of construction, based on article 95 of the Treaty. The objective of the programme was the elimination of technical obstacles to trade and the harmonisation of technical specifications. Within this action programme, the Commission took the initi
19、ative to establish a set of harmonised technical rules for the design of construction works which, in a first stage, would serve as an alternative to the national rules in force in the Member States and, ultimately, would replace them. For fifteen years, the Commission, with the help of a Steering C
20、ommittee with Representatives of Member States, conducted the development of the Eurocodes programme, which led to the first generation of European codes in the 1980s. In 1989, the Commission and the Member States of the EU and EFTA decided, on the basis of an agreement1 between the Commission and C
21、EN, to transfer the preparation and the publication of the Eurocodes to CEN through a series of Mandates, in order to provide them with a future status of European Standard (EN). This links de facto the Eurocodes with the provisions of all the Councils Directives and/or Commissions Decisions dealing
22、 with European Standards (e.g. the Council Directive 89/106/EEC on construction products - CPD - and Council Directives 93/37/EEC, 92/50/EEC and 89/440/EEC on public works and services and equivalent EFTA Directives initiated in pursuit of setting up the internal market). The Structural Eurocode pro
23、gramme comprises the following standards generally consisting of a number of Parts: EN 1990, Eurocode: Basis of structural design. EN 1991, Eurocode 1: Actions on structures. prEN 1992, Eurocode 2: Design of concrete structures. prEN 1993, Eurocode 3: Design of steel structures. 1 Agreement between
24、the Commission of the European Communities and the European Committee for Standardisation (CEN) concerning the work on EUROCODES for the design of building and civil engineering works (BC/CEN/03/89). EN 1991-1-2:2002 (E) 5 prEN 1994, Eurocode 4: Design of composite steel and concrete structures. prE
25、N 1995, Eurocode 5: Design of timber structures. prEN 1996, Eurocode 6: Design of masonry structures. prEN 1997, Eurocode 7: Geotechnical design. prEN 1998, Eurocode 8: Design of structures for earthquake resistance. prEN 1999, Eurocode 9: Design of aluminium structures. Eurocode standards recognise
26、 the responsibility of regulatory authorities in each Member State and have safeguarded their right to determine values related to regulatory safety matters at national level where these continue to vary from State to State. Status and field of application of Eurocodes The Member States of the EU an
27、d EFTA recognise that EUROCODES serve as reference documents for the following purposes: as a means to prove compliance of building and civil engineering works with the essential requirements of Council Directive 89/106/EEC, particularly Essential Requirement N1 - Mechanical resistance and stability
28、 - and Essential Requirement N2 - Safety in case of fire; as a basis for specifying contracts for construction works and related engineering services; as a framework for drawing up harmonised technical specifications for construction products (ENs and ETAs). The Eurocodes, as far as they concern the
29、 construction works themselves, have a direct relationship with the Interpretative Documents2 referred to in Article 12 of the CPD, although they are of a different nature from harmonised product standards3. Therefore, technical aspects arising from the Eurocodes work need to be adequately considere
30、d by CEN Technical Committees and/or EOTA Working Groups working on product standards with a view to achieving full compatibility of these technical specifications with the Eurocodes. The Eurocode standards provide common structural design rules for everyday use for the design of whole structures an
31、d component products of both a traditional and an innovative nature. Unusual forms of construction or design conditions are not specifically covered and additional expert consideration will be required by the designer in such cases. 2 According to Art. 3.3 of the CPD, the essential requirements (ERs
32、) shall be given concrete form in interpretative documents for the creation of the necessary links between the essential requirements and the mandates for harmonised ENs and ETAGs/ETAs. 3 According to Art. 12 of the CPD the interpretative documents shall: a)give concrete form to the essential requir
33、ements by harmonising the terminology and the technical bases and indicating classes or levels for each requirement where necessary; b)indicate methods of correlating these classes or levels of requirement with the technical specifications, e.g. methods of calculation and of proof, technical rules f
34、or project design, etc.; c)serve as a reference for the establishment of harmonised standards and guidelines for European technical approvals. The Eurocodes, de facto, play a similar role in the field of the ER 1 and a part of ER 2. EN 1991-1-2:2002 (E) 6 National standards implementing Eurocodes Th
35、e national standards implementing Eurocodes will comprise the full text of the Eurocode (including any annexes), as published by CEN, which may be preceded by a national title page and national foreword, and may be followed by a national annex. The national annex may only contain information on thos
36、e parameters which are left open in the Eurocode for national choice, known as Nationally Determined Parameters, to be used for the design of buildings and civil engineering works to be constructed in the country concerned, i.e.: values and/or classes where alternatives are given in the Eurocode; va
37、lues to be used where a symbol only is given in the Eurocode; country specific data (geographical, climatic, etc), e.g. snow map; the procedure to be used where alternative procedures are given in the Eurocode. It may also contain: decisions on the application of informative annexes and references t
38、o non-contradictory complementary information to assist the user to apply the Eurocode. Links between Eurocodes and harmonised technical specifications (ENs and ETAs) for products There is a need for consistency between the harmonised technical specifications for construction products and the techni
39、cal rules for works4. Furthermore, all the information accompanying the CE Marking of the construction products which refer to Eurocodes shall clearly mention which Nationally Determined Parameters have been taken into account. Additional information specific to EN 1991-1-2 EN 1991-1-2 describes the
40、 thermal and mechanical actions for the structural design of buildings exposed to fire, including the following aspects: Safety requirements EN 1991-1-2 is intended for clients (e.g. for the formulation of their specific requirements), designers, contractors and relevant authorities. The general obj
41、ectives of fire protection are to limit risks with respect to the individual and society, neighbouring property, and where required, environment or directly exposed property, in the case of fire. Construction Products Directive 89/106/EEC gives the following essential requirement for the limitation
42、of fire risks: 4 See Art.3.3 and Art.12 of the CPD, as well as 4.2, 4.3.1, 4.3.2 and 5.2 of ID N1. EN 1991-1-2:2002 (E) 7 “The construction works must be designed and built in such a way, that in the event of an outbreak of fire the load bearing resistance of the construction can be assumed for a sp
43、ecified period of time, the generation and spread of fire and smoke within the works are limited, the spread of fire to neighbouring construction works is limited, the occupants can leave the works or can be rescued by other means, the safety of rescue teams is taken into consideration“. According t
44、o the Interpretative Document N2 “Safety in Case of Fire5“ the essential requirement may be observed by following various possibilities for fire safety strategies prevailing in the Member States like conventional fire scenarios (nominal fires) or “natural“ (parametric) fire scenarios, including pass
45、ive and/or active fire protection measures. The fire parts of Structural Eurocodes deal with specific aspects of passive fire protection in terms of designing structures and parts thereof for adequate load bearing resistance and for limiting fire spread as relevant. Required functions and levels of
46、performance can be specified either in terms of nominal (standard) fire resistance rating, generally given in national fire regulations or, where allowed by national fire regulations, by referring to fire safety engineering for assessing passive and active measures. Supplementary requirements concer
47、ning, for example: the possible installation and maintenance of sprinkler systems; conditions on occupancy of building or fire compartment; the use of approved insulation and coating materials, including their maintenance are not given in this document, because they are subject to specification by t
48、he competent authority. Numerical values for partial factors and other reliability elements are given as recommended values that provide an acceptable level of reliability. They have been selected assuming that an appropriate level of workmanship and of quality management applies. Design procedures
49、A full analytical procedure for structural fire design would take into account the behaviour of the structural system at elevated temperatures, the potential heat exposure and the beneficial effects of active and passive fire protection systems, together with the uncertainties associated with these three features and the importance of the structure (consequences of failure). 5 See 2.2, 3.2(4) and 4.2.3.3 of ID N2. EN 1991-1-2:2002 (E) 8 At the present time it is possible to undertake a procedure for determining adequate performance w