BS EN 1995-1-2-2004 Eurocode 5 Design of timber structures - General - Structural fire design《欧洲法规5 木结构的设计 总则 结构防火设计》.pdf

1、BRITISH STANDARDBS EN 1995-1-2:2004Incorporating corrigendaEurocode 5: Design of timber structures Part 1-2: General Structural fire designICS 13.220.50; 91.010.30; 91.080.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g

2、51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58June 2006 andMarch 2009National forewordThis British Standard is the UK implementation of EN 1995-1-2:2004, incorporating corrigenda June 2006 and March 2009. It supersedes DD ENV 1995-1-2:2000 which is withdrawn. The start an

3、d finish of text introduced or altered by corrigendum is indicated in the text by tags. Text altered by CEN corrigendum March 2009 is indicated in the text by (which supersedes the changes incorporated by CEN corrigendum June 2006).The structural Eurocodes are divided into packages by grouping Euroc

4、odes for each of the main materials: concrete, steel, composite concrete and steel, timber, masonry and aluminium; this is to enable a common date of withdrawal (DOW) for all the relevant parts that are needed for a particular design. The conflicting national standards will be withdrawn at the end o

5、f the co-existence period, after all the EN Eurocodes of a package are available.Following publication of the EN, there is a period allowed for the national calibration during which the National Annex is issued, followed by a co-existence period of a maximum three years. During the co-existence peri

6、od Member States are encouraged to adapt their national provisions.At the end of this co-existence period, the conflicting parts of national standard(s) will be withdrawn.In the UK, the primary corresponding national standards are: BS 5268-4.1:1978, Structural use of timber Part 4: Fire resistance o

7、f timber structures Section 4.1: Recommendations for calculating fire resistance of timber members; BS 5268-4.2:1990, Structural use of timber Part 4: Fire resistance of timber structures Section 4.2: Recommendations for calculating fire resistance of timber stud walls and joisted floor construction

8、s; and based on this transition period, these standards will be withdrawn on a date to be announced, but at the latest by March 2010.The UK participation in its preparation was entrusted by Technical Committee B/525, Building and civil engineering structures, to Subcommittee B/525/5, Structural use

9、of timber.A list of organizations represented on this subcommittee can be obtained on request to its secretary.BS EN 1995-1-2:2004Amendments/corrigenda issued since publicationAmd. No. Date Comments 16498 Corrigendum No. 131 July 2006 Implementation of CEN corrigendum June 200631 August 2009 Impleme

10、ntation of CEN corrigendum March 2009This British Standard was published under the authority of the Standards Policy and Strategy Committee on 15 December 2004 BSI 2009ISBN 978 0 580 67354 2Where a normative part of this EN allows for a choice to be made at the national level, the range and possible

11、 choice will be given in the normative text, and a note will qualify it as a Nationally Determined Parameter (NDP). NDPs can be a specific value for a factor, a specific level or class, a particular method or a particular application rule if several are proposed in the EN.To enable EN 1995-1-2 to be

12、 used in the UK, the NDPs will be published in a National Annex, which will be made available by BSI in due course, after public consultation has taken place.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Com

13、pliance with a British Standard cannot confer immunity from legal obligations.BS EN 1995-1-2:2004iiiblankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1995-1-2 November 2004 ICS 91.010.30; 13.220.50; 91.080.20 Supersedes ENV 1995-1-2:1994 English version Eurocode 5: Design of timber structure

14、s - Part 1-2: General - Structural fire design Eurocode 5: Conception et Calcul des structures en bois - Part 1-2: Gnralits - Calcul des structures au feu Eurocode 5: Entwurf, Berechnung und Bemessung von Holzbauten - Teil 1-2: Allgemeine Regeln - Bemessung fr den Brandfall This European Standard wa

15、s approved by CEN on 16 April 2004. 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. Up-to-date lists and bibliographical references concerning such nat

16、ional standards may be obtained on application to the Central Secretariat or to any CEN member. This European 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 n

17、otified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Neth

18、erlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2004 CEN All rights of exploitation in any

19、 form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1995-1-2:2004: EIncorporating corrigenda June 2006 and March 20092 Contents Foreword 4 Background of the Eurocode programme 4 Status and field of application of Eurocodes 5 National Standards implementing Eurocodes 5 Lin

20、ks between Eurocodes and harmonised technical specifications (ENs and ETAs) for products 6 Additional information specific to EN 1995-1-2 6 National annex for EN 1995-1-2 7 Section 1 General 9 1.1 Scope 9 1.1.1 Scope of Eurocode 5 9 1.1.2 Scope of EN 1995-1-2 9 1.2 Normative references 10 1.3 Assump

21、tions 10 1.4 Distinction between principles and application rules 10 1.5 Terms and definitions 11 1.6 Symbols 11 Section 2 Basis of design 14 2.1 Requirements 14 2.1.1 Basic requirements 14 2.1.2 Nominal fire exposure 14 2.1.3 Parametric fire exposure 14 2.2 Actions 15 2.3 Design values of material

22、properties and resistances 15 2.4 Verification methods 16 2.4.1 General 16 2.4.2 Member analysis 17 2.4.3 Analysis of parts of the structure 18 2.4.4 Global structural analysis 19 Section 3 Material properties 20 3.1 General 20 3.2 Mechanical properties 20 3.3 Thermal properties 20 3.4 Charring dept

23、h 20 3.4.1 General 20 3.4.2 Surfaces unprotected throughout the time of fire exposure 21 3.4.3 Surfaces of beams and columns initially protected from fire exposure 23 3.4.3.1 General 23 3.4.3.2 Charring rates 26 3.4.3.3 Start of charring 27 3.4.3.4 Failure times of fire protective claddings 28 3.5 A

24、dhesives 29 Section 4 Design procedures for mechanical resistance 30 4.1 General 30 4.2 Simplified rules for determining cross-sectional properties 30 4.2.1 General 30 4.2.2 Reduced cross-section method 30 4.2.3 Reduced properties method 31 4.3 Simplified rules for analysis of structural members and

25、 components 32 4.3.1 General 32 4.3.2 Beams 32 4.3.3 Columns 33 4.3.4 Mechanically jointed members 33 4.3.5 Bracings 34 4.4 Advanced calculation methods 34 Section 5 Design procedures for wall and floor assemblies 35 BS EN 1995-1-2:2004EN 1995-1-2:2004 (E)3 5.1 General 35 5.2 Analysis of load-bearin

26、g function 35 5.3 Analysis of separating function 35 Section 6 Connections 36 6.1 General 36 6.2 Connections with side members of wood 36 6.2.1 Simplified rules 36 6.2.1.1 Unprotected connections 36 6.2.1.2 Protected connections 37 6.2.1.3 Additional rules for connections with internal steel plates

27、38 6.2.2 Reduced load method 39 6.2.2.1 Unprotected connections 39 6.2.2.2 Protected connections 41 6.3 Connections with external steel plates 41 6.3.1 Unprotected connections 41 6.3.2 Protected connections 41 6.4 Simplified rules for axially loaded screws 41 Section 7 Detailing 43 7.1 Walls and flo

28、ors 43 7.1.1 Dimensions and spacings 43 7.1.2 Detailing of panel connections 43 7.1.3 Insulation 43 7.2 Other elements 43 Annex A (Informative) Parametric fire exposure 45 A1 General 45 A2 Charring rates and charring depths 45 A3 Mechanical resistance of members in edgewise bending 47 Annex B (infor

29、mative) Advanced calculation methods 48 B1 General 48 B2 Thermal properties 48 B3 Mechanical properties 50 Annex C (Informative) Load-bearing floor joists and wall studs in assemblies whose cavities are completely filled with insulation 52 C1 General 52 C2 Residual cross-section 52 C2.1 Charring rat

30、es 52 C2.2 Start of charring 54 C2.3 Failure times of panels 54 C3 Reduction of strength and stiffness parameters 56 Annex D (informative) Charring of members in wall and floor assemblies with void cavities 58 D1 General 58 D2 Charring rates 58 D3 Start of charring 58 D4 Failure times of panels 58 A

31、nnex E (informative) Analysis of the separating function of wall and floor assemblies 60 E1 General 60 E2 Simplified method for the analysis of insulation 60 E2.1 General 60 E2.2 Basic insulation values 61 E2.3 Position coefficients 62 E2.4 Effect of joints 62 Annex F (informative) Guidance for user

32、s of this Eurocode Part 68 BS EN 1995-1-2:2004EN 1995-1-2:2004 (E)4 Foreword This European Standard EN 1995-1-2 has been prepared by Technical Committee CEN/TC250 “Structural Eurocodes”, the Secretariat of which is held by BSI. This European Standard shall be given the status of a National Standard,

33、 either by publication of an identical text or by endorsement, at the latest by May 2005, and conflicting national standards shall be withdrawn at the latest by March 2010. This European Standard supersedes ENV 1995-1-2:1994. CEN/TC250 is responsible for all Structural Eurocodes. According to the CE

34、N/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxemburg,

35、 Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Background of the Eurocode programme In 1975, the Commission of the European Community decided on an action programme in the field of construction, based on article 95 of the Treaty. The

36、 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 initiative to establish a set of harmonised technical rules for the design of construction works which, in a first

37、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 Committee with Representatives of Member States, conducted the development of the Eurocodes programme, which le

38、d 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 agreement1between the Commission and CEN, to transfer the preparation and the publication of the Eurocodes to the CEN through a series of Mandates, i

39、n 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 with European standards (e.g. the Council Directive 89/106/EEC on construction products - CPD - and Counci

40、l 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 programme comprises the following standards generally consisting of a number of Parts: EN 1990 Eurocode : Basi

41、s of Structural 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 structures EN 1995 Eurocode 5: Design of timber structures EN 1996 Eurocode 6:

42、Design of masonry structures EN 1997 Eurocode 7: Geotechnical design 1Agreement between 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). BS EN 1995-1

43、-2:2004EN 1995-1-2:2004 (E)5 EN 1998 Eurocode 8: Design of structures for earthquake resistance EN 1999 Eurocode 9: Design of aluminium structures Eurocode standards recognise the responsibility of regulatory authorities in each Member State and have safeguarded their right to determine values relat

44、ed 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 and EFTA recognise that EUROCODES serve as reference documents for the following purposes: as a means to prove compliance of bu

45、ilding and civil engineering works with the essential requirements of Council Directive 89/106/EEC, particularly Essential Requirement N1 Mechanical resistance and stability and Essential Requirement N2 Safety in case of fire; as a basis for specifying contracts for construction works and related en

46、gineering services; as a framework for drawing up harmonised technical specifications for construction products (ENs and ETAs). The Eurocodes, as far as they concern the construction works themselves, have a direct relationship with the Interpretative Documents2referred to in Article 12 of the CPD,

47、although they are of a different nature from harmonised product standards3. Therefore, technical aspects arising from the Eurocodes work need to be adequately considered by CEN Technical Committees and/or EOTA Working Groups working on product standards with a view to achieving full compatibility of

48、 these technical specifications with the Eurocodes. The Eurocode standards provide common structural design rules for everyday use for the design of whole structures and component products of both a traditional and an innovative nature. Unusual forms of construction or design conditions are not spec

49、ifically covered and additional expert consideration will be required by the designer in such cases. National Standards implementing Eurocodes The 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 those parameters which are left open in the Eurocode for national choice, known as Nationally Determine