08-30145245-DC.pdf

a Date: 28 July 2008 Origin: National Latest date for receipt of comments: 30 September 2008 Project no.: 2006/00244 Responsible committee: B/525/1 Actions (loadings) and basis of design Interested committees: Title: Draft BS BS EN 1990(A1) UK National Annex for Eurocode Basis of structural design Supersession information: If this document is published as a standard, the UK implementation of it will supersede BSEN1990 : 2002 NATIONAL ANNEX and partially supersede. NONE If you are aware of a current national standard which may be affected, please notify the secretary (contact details below). WARNING: THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 September 2008. This draft is issued to allow comments from interested parties; all comments will be given consideration prior to publication. No acknowledgement will normally be sent. See overleaf for information on commenting. No copying is allowed, in any form, without prior written permission from BSI except as permitted under the Copyright, Designs and Patent Act 1988 or for circulation within a nominating organization for briefing purposes. Electronic circulation is limited to dissemination by e-mail within such an organization by committee members. Further copies of this draft may be purchased from BSI Customer Services, Tel: +44(0) 20 8996 9001 or email cservicesbsigroup.com. British, International and foreign standards are also available from BSI Customer Services. Information on the co-operating organizations represented on the committees referenced above may be obtained from the responsible committee secretary. Cross-references The British Standards which implement International or European publications referred to in this draft may be found via the British Standards Online Service on the BSI web site http:/www.bsigroup.com. Direct tel: 020 8996 7156 Responsible Committee Secretary: Ms C Price (BSI) E-mail: clare.pricebsigroup.com Draft for Public Comment Head Office 389 Chiswick High Road London W4 4AL Telephone: +44(0)20 8996 9000 Fax: +44(0)20 8996 7001 Form 36 Version 8.0 DPC: 08/30145245 DC Licensed CopyChinese University of Hong Kong, 21/10/2008 03:56, Uncontrolled Copy, (c) BSI b Introduction Your comments on this draft are invited and will assist in the preparation of the resulting British Standard. If no comments are received to the contrary, this draft may be implemented unchanged as a British Standard. Please note that this is a draft and not a typeset document. Editorial comments are welcomed, but you are advised not to comment on detailed matters of typography and layout. Submission of comments The guidance given below is intended to ensure that all comments receive efficient and appropriate attention by the responsible BSI committee. This draft British Standard is available for review and comment online via the BSI British Standards Draft Review system at http:/drafts.bsigroup.com. Registration is free and takes less than a minute. Once you have registered on the Draft Review system you will be able to review all current draft British Standards of national origin and submit comments on them. You will also be able to see comments made on current draft standards by other interested parties. When submitting comments on a draft you will be asked to provide both a comment (i.e. justification for change) and a proposed change. All comments will be checked by a moderator before they are made public on the site. This is to ensure that improper language or marketing is not placed on the site the technical content of your comment will not be judged or modified; similarly, your grammar or spelling will not be corrected. A link to the BSI British Standards Draft Review system, or to a specific draft hosted on the system, may be distributed to other interested parties so that they may register and submit comments. It is not necessary to purchase a copy of the draft in order to review or comment on it; however, additional copies of this draft may be purchased from BSI, Tel: +44(0) 20 8996 9001 or email: cservicesbsigroup.com. Drafts and standards are also available in PDF format for immediate download from the BSI Shop http:/www.bsigroup.com/Shop. Licensed CopyChinese University of Hong Kong, 21/10/2008 03:56, Uncontrolled Copy, (c) BSI WARNING. THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 SEPT 2008. 1 Amendment 1 to NA to BS EN 1990:2002+A1:2005, Basis of structural design The following instructions form the amendment (alterations and additions) to this National Annex. Only affected subclauses are included. Contents of this amendment Title 1 Introduction 1 NA.1 Scope 2 NA.2 Nationally determined parameters 3 NA.3 Guidance on using the informative annexes B, C and D 15 NA.4 Reference to non-contradictory complementary information (NCCI) 15 Bibliography (new section) 17 List of tables Table NA.A1.2(B) Design values of actions (STR/GEO) (Set B) 3 Table NA.A.2.1 Recommended values of factors for road bridges 5 Table NA.A.2.2 Recommended values of factors for footbridges 5 Table NA.A.2.3 Recommended values of factors for railway bridges 6 Table NA.A.2.4(A) Design values of actions (EQU) (Set A) 8 Table NA.A.2.4(B) Design values of actions (STR/GEO) (Set B) 10 Table NA.A.2.4(C) Design values of actions (STR/GEO) (Set C) 12 Title Change title from: “UK National Annex for Eurocode 0 Basis of structural design” to: “UK National Annex to Eurocode Basis of structural design”. Introduction Replace: “This National Annex has been prepared by BSI Subcommittee B/525/1, Actions (loadings) and basis of design and it is to be used in conjunction with BS EN 1990:2002: Eurocode Basis of structural design.” with: “This National Annex has been prepared by BSI Subcommittee B/525/1, Actions (loadings) and basis of design. In the UK, it is to be used in conjunction with BS EN 1990:2002+A1:2005. The start and finish of text introduced or altered by Amendment No. 1 will be indicated in the text by tags.” Licensed CopyChinese University of Hong Kong, 21/10/2008 03:56, Uncontrolled Copy, (c) BSI WARNING. THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 SEPT 2008. 2 NA.1 Scope Replace items c) and d) in NA.1.1 with: “c) the UK decisions for the Nationally Determined Parameters described in the following subclauses of BS EN 1990:2002+A1:2005: A.2.1(1) NOTE 3 A.2.2.1 (2) NOTE 1 A.2.2.2 (1), (3), (4), (6) A.2.2.3 (2), (3), (4) A.2.2.4 (1), (4) A.2.2.6 (1) NOTE 1, NOTE 2, NOTE 3 A.2.3.1 (1), (5), (7), (8) A.2.3.2 (1), Table A2.5 NOTE A.2.4.1 (1) NOTE 1, Table A2.6 NOTE 2; (2) NOTE A.2.4.3.2 (1) A.2.4.4.1 (1) NOTE 3 A.2.4.4.2.1 (4)P A.2.4.4.2.2 Table A2.7 NOTE A.2.4.4.2.2 (3)P A.2.4.4.2.3 (1) A.2.4.4.2.3 (2), (3) A.2.4.4.2.4 (2), Table A2.8 NOTE 3 A.2.4.4.2.4 (3) A.2.4.4.3.2 (6) NOTE Clauses applicable for cranes and machinery; silos and tanks, etc. will be added by amending the National Annex at appropriate future dates. d) Guidance on use of the Informative Annexes B, C and D for buildings and civil engineering works. (See NA.3.1.) e) Guidance on use of the Informative Annexes B, C and D for bridges. (See NA.3.2.) f) References to non-contradictory complementary information applicable to buildings and civil engineering works. (See NA.4.1.) g) References to non-contradictory complementary information applicable to bridges. (See NA.4.2.)” Licensed CopyChinese University of Hong Kong, 21/10/2008 03:56, Uncontrolled Copy, (c) BSI WARNING. THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 SEPT 2008. 3 NA.2 Nationally determined parameters NA.2.2.3.2 Values for the symbols and of Table A1.2 (B) Table NA.A1.2(B) Design values of actions (STR/GEO) (Set B) In NOTE 3, replace: “A value of sd in the range 1,05 to 1,15 can be used in most common cases and can be modified in the National Annex.” with “A value of sd = 1,15 can be used except where otherwise defined for the individual project.” NA.2.2.6 Clause A1.4.2 Delete: “Nationally determined parameters for EN 1990 Eurocode Basis of Design Annex A2 Application for Bridges and other Annexes (e.g. cranes and machinery, silos and tanks, towers and masts) will be added when available.” NA.2.3 Nationally determined parameters for bridges (new subclause) NA.2.3.1 BS EN 1990(A1):2005, A.2.1(1), Note 3 Field of application Table NA.A.2.1 provides modified values for the design working life for bridges given in BS EN 1990(A1):2005, Table A.2.1. NA.2.3.2 BS EN 1990(A1):2005, A.2.2.1(2), Note 1 General Combinations involving actions that are outside the scope of BS EN 1991 may be defined for the individual project taking account of the general probability of simultaneous occurrence of different load components following the principles given in BS EN 1990. NA.2.3.3 BS EN 1990(A1):2005, A.2.2.2 Combination rules for road bridges NA.2.3.3.1 A.2.2.2(1), Note Infrequent combination of actions need not be used. NA.2.3.3.2 A.2.2.2(3), Note The combination rules for special vehicles with normal traffic are given in the National Annex to BS EN 1991-2. The values of and factors given in this National Annex should be used. NA.2.3.3.3 A.2.2.2(4), Note Snow loads may generally be ignored in the UK. However, in special cases (for example moving bridges) where snow loads can be critical for stability, the combination of snow loads and groups of loads gr1a and gr1b may be defined for the individual project. Licensed CopyChinese University of Hong Kong, 21/10/2008 03:56, Uncontrolled Copy, (c) BSI WARNING. THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 SEPT 2008. 4 NA.2.3.3.4 A.2.2.2(6), Note The combination of wind and thermal actions may generally be ignored in the UK. In special cases where this may be appropriate, the combination of wind and thermal actions may be defined for the individual project. NA.2.3.4 BS EN 1990(A1):2005, A.2.2.3 Combination rules for footbridges NA.2.3.4.1 A.2.2.3(2), Note The combination of wind and thermal actions may generally be ignored in the UK. In special cases where this may be appropriate, the combination of wind and thermal actions may be defined for the individual project. NA.2.3.4.2 A.2.2.3(3), Note Snow loads may generally be ignored in the UK. However, in special cases (for example moving bridges) where snow loads can be critical for stability, the combination of snow loads and groups of loads gr1a and gr1b may be defined for the individual project. NA.2.3.4.3 A.2.2.3(4), Note Specific combinations of actions for footbridges on which pedestrian and cycle traffic is fully protected from all types of bad weather may be defined as appropriate for the individual project. NA.2.3.5 BS EN 1990(A1):2005, A.2.2.4Combination rules for railway bridges NA.2.3.5.1 A.2.2.4(1), Note Snow loads may generally be ignored in the UK. The types of railway bridge, for which snow loads need to be taken into account, should be determined for the individual project. NA.2.3.5.2 A.2.2.4(4), Note The limit of maximum peak velocity pressure qp(z), derived from the maximum wind speed, that is compatible with rail traffic, for determination of FW*, is given in NA to BS EN 1991-1-4. NA.2.3.6 BS EN 1990(A1):2005, A.2.2.6 Values of factors NA.2.3.6.1 A.2.2.6(1), Note 1 Table NA.A.2.1 gives recommended values of factors for road bridges to be used instead of Table A.2.1 of BS EN 1990:2002+A1:2005. Table NA.A.2.2 gives recommended values of factors for footbridges to be used instead of Table A.2.2 of BS EN 1990:2002+A1:2005. Table NA.A.2.3 gives recommended values of factors for railway bridges to be used instead of Table A.2.3 of BS EN 1990:2002+A1:2005. NA.2.3.6.2 A.2.2.6(1), Note 2 The factors specified for a group of loads apply to all the component actions in that group, except for gr1a where they are individually specified. NA.2.3.6.3 A.2.2.6(1), Note 3 Where relevant, representative values of water actions Fwa should be determined for the individual project. Licensed CopyChinese University of Hong Kong, 21/10/2008 03:56, Uncontrolled Copy, (c) BSI WARNING. THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 SEPT 2008. 5 Table NA.A.2.1 Recommended values of factors for road bridges Action Group of Loads Load components 0 1 2 2 TS 0,75 0,75 0 UDL 0,75 0,75 0 gr1a(1) Pedestrian and cycle-track loads(2) 0,40 0,40 0 gr1b(1) Single Axle 0 0,75 0 gr2 Horizontal Forces 0 0 0 gr3 Pedestrian Loads 0 0.40 0 gr4 Crowd Loading 0 0,75 0 gr5 Vertical Forces from SV and SOV Vehicles 0 1.0(4) 0 Traffic loads gr6 Horizontal Forces from SV and SOV Vehicles 0 0 0 During execution 0,50 0,20 0 FWk Persistent design situations 0,80 - 0 Wind forces F*W During execution 1,0 - 0 Thermal actions Tk 0,60(3) 0,60 0,50 Snow loads QSn,k 0,80 - - Construction loads Qc 1,0 1,0 1) The recommended values of 0, 1, 2 for gr1a and gr1b are given for roads with traffic corresponding to adjusting factors Qi, qi, qr and Q defined in the UK National Annex to BS EN 1991-2. 2) The value of the pedestrian and cycle-track load given in BS EN 1991-2:2003, Table A.4.4a, is a “reduced” value accompanying the characteristic value of LM1 and should not be factored again by 1. However, when gr1a is combined with leading non-traffic actions this value should be factored by 0. 3) The recommended 0 values for thermal actions may in most cases be reduced to 0 for ultimate limit states EQU, STR and GEO. See also the design Eurocodes. 4) The frequent value of load group gr5 does not need to be considered in accordance with EN1991-2 Clause 4.5.2. Table NA.A.2.2 Recommended values of factors for footbridges Action Symbol 0 1 2 gr1 0,4 0,4 0 Qfwk 0 0 0 Traffic loads gr2 0 0 0 Wind forces FWk 0,3 0,2 0 Thermal actions Tk 0,6(1) 0,6 0,5 Snow loads QSn,k (during execution) 0,8 - 0 Construction loads Qc 1,0 - 1,0 1) The recommended 0 values for thermal actions may in most cases be reduced to 0 for ultimate limit states EQU, STR and GEO. See also the design Eurocodes. Licensed CopyChinese University of Hong Kong, 21/10/2008 03:56, Uncontrolled Copy, (c) BSI WARNING. THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 30 SEPT 2008. 6 Table NA.A.2.3 Recommended values of factors for railway bridges Actions 0 1 24) LM71 SW/0 SW/2 Unloaded train HSLM 0,80 0,80 0 1,00 1,00 1) 1) 1,00 - 1,00 0 0 0 - 0 Traction and braking Centrifugal forces Interaction forces due to deformation under vertical traffic loads Individual components of traffic actions in design situations where the traffic loads are considered as a single (multi-directional) leading action and n