N 1069 CEN-TC250-WG7 N0001 EG EN1990

Transcription

1 CEN/TC 250 CEN/TC Structural Eurocodes of secretary: tracey.wilkins@bsigroup.com Secretariat: BSI (United Kingdom) N 1069 CEN-TC250-WG7 N0001 EG EN Recommendations for amendments to EN 1990 "4-columnversion". Document type: Date of document: Other committee document Expected action: INFO Background: Committee URL:

2 CEN/TC 250/WG 7 N 1 CEN/TC 250/WG 7 CEN/TC 250/WG 7 - EN 1990 Basis of structural design of secretary: vme@standard.no Secretariat: SN (Norway) EG EN Recommendations for amendments to EN Document type: Other committee document Date of document: Expected action: INFO Background: Committee URL:

3 CEN/TC250 STRUCTURAL EUROCODE EN1990 BASIS OF STRUCTURAL DESIGN EXPERT GROUP FOR EVOLUTION OF EN 1990 RECOMMENDATIONS FOR AMENDMENDS TO EN 1990 (at February 2013) NOTE This document has been prepared by the EG EN1990 and has the status of a Working Draft, it is intended for use by WG7 and its PTs, to serve as a basis for the future discussion on the evolution of EN The document is in evolution and will be completed/updated by WG7. As recalled in the introduction hereafter, the recommendations are based on the comments received by the EN1990 review, submitted by some NSBs and other requirements made by TC250 sub-committees and CEN execution standards committees, up to February Notwithstanding the above considerations, WG7 (London, ) agreed to circulate this draft within CEN/TC250, for information purposes only. EXPERT GROUP: H Gulvanessian S Leivestad P Formichi P Luechinger A Bond J Markova J Bregulla J Sorenson P Croce P Spehl S Denton T Vrouwenvelder W Jaeger Draft: 2013/11/05

4 Table of contents Introduction... 3 FOREWORD... 5 Section 1 General Section 2 Requirements Section 3 Principles of limit states design Section 4 Basic Variables Section 5 Structural analysis and design assisted by testing Section 6 Verification by the partial factor method Annex A1 (normative) Application for Buildings Annex B Annex C Appendix 1 PROPOSAL FOR THE MINIMUM CONTENTS OF THE STRUCTURAL DESIGN REPORT Appendix 2 PROPOSAL FOR THE ULS VERIFICATIONS FORMAT STR/EQU/GEO Appendix 3 BACKGROUND CALCULATIONS EQU/STR Appendix 4 PROPOSAL FOR THE AMENDMENT OF TABLE A1.2(B) Appendix 5 - ALTERNATIVE PROPOSAL BY WOLFRAM JÄGER FOR ANNEX B

5 Introduction The EG was set up by TC250 through its resolution n at the meeting in Limassol (Cyprus) in October 2007, and met for the first time in Brussels on 2 nd of July Eight subsequent meetings were held until February The EG worked on the comments given by the EN1990 review, submitted by some NSBs and other requirements made by TC250 sub-committees and CEN execution standards committees. At these meetings it was decided that recommendations for changes from the EG should be presented in a consistent four column version style as follows: Column 1: list all Clause numbers Column 2: gives the current (EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010) content of a clause for which a change is recommended Column 3: if no change is recommended to a Clause then in Column 3 no change is written; if a change is recommended to a Clause, Column 3 gives the proposed new Clause with highlighting so that suggested amendments are readily identified Column 4: where changes are recommended, gives the background for the recommendation This report gives the whole set of recommendations agreed by the EG until February In preparing the recommendations the EG gave strong consideration to the needs of practitioners and the need for stability of EN1990. Decisions were also taken to keep annexes B, C and D informative. The main recommendations for changes include: - Changes requested by NSBs; 1 Resolution 243 (CEN/TC 250, Limassol, 15/16th October 2007) Subject: EN Results of the 5 year inquiry CEN TC 250 notes the results of the 5 year review of EN 1990 Basis of structural design agreeing to the confirmation and notes that a corrigendum will be issued as soon as possible. CEN/TC also agrees to the formation of an expert Group, under the Convenorship of Prof Haig Gulvanessian, to prepare the first revision of EN The resolution was agreed by unanimity. 3

6 - New guidance on non linear analysis (requested by CEN/TC250/SC2) and design for fatigue (requested by CEN/TC250/SC2-SC3). These are general clauses which will be duly implemented in the relevant material codes; - Changes to Annex B (requested by CEN/TC250/SC3 and steel and aluminium execution standards), and improving the clarity of annex C. In addition the recommendations include five Appendices for the future WG/PT to consider as follows: Proposal for the minimum contents of the Structural Design Report Proposals for the verification format for STR, EQU, GEO, more appropriate for structures below ground Background calculations for EQU/STR Proposal for the amendment of Table A1.2(B) Alternative proposals for Annex B made by Wolfram Jaeger. Accompanying this document the EG has prepared a track change version of EN 1990 showing all the recommendations. Annex A2 (bridges) has not yet been developed. Initial drafts of Annex A3 (towers and masts) is included and advanced drafts of Annexes A4 (silos and tanks) and A5 (cranes and machinery) are included. 4

7 FOREWORD Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation Foreword This document (EN 1990:2002) 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, either by publication of an identical text or by endorsement, at the latest by October 2002, and conflicting national standards shall be withdrawn at the latest by March This document supersedes ENV :1994. CEN/TC 250 is responsible for all Structural Eurocodes. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, This European Standard (EN 1990:xxxx) has been prepared by Technical Committee CEN/TC 250 "Structural Eurocodes", the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard. According to the CEN/CENELEC Internal Regulations, the National Standards Organizations of EU and EFTA Member States are bound to implement this European Standard. This document supersedes EN 1990: A1:2005 and including corrigenda dated December 2008 and April CEN/TC 250 is responsible for all Structural Eurocodes. This paragraph has been updated and the list of, the national standards organizations of the countries is removed in accordance with current CEN procedures. Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,Spain, Sweden, Switzerland and the United Kingdom. 5

8 Clause Foreword to amendment A1 EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 This European Standard (EN 1990:2002/A1:2005) has been prepared by Technical Committee CEN/TC 250 Structural Eurocodes, the secretariat of which is held by BSI. This Amendment to the EN 1990:2002 shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2006, and conflicting national standards shall be withdrawn at the latest by June According to the CEN/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,Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation No need for this part of the foreword in the new version. 6

9 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation 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 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 stage, would serve as an alternative to national provisions the 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 led to the first generation of European codes in the 1980 s. In 1975, the Commission of the European Community decided on an action programme in the field of construction, based on article 95 of the 1957 Treaty of Rome. 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 initiative to establish a set of harmonised technical rules for the design of construction works intended to replace the national provisions in the Member States. 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 led to the first generation of European standards in the 1980 s. Increased clarity and corrected terminology (e.g. European Standards and not European Codes) has been used. Updated references for the CPR and the Procurement Directives are given. Notice given that the list of Eurocodes will increase as new Eurocodes are developed. In 1989, the Commission and the Member States of the EU and EFTA decided, on the basis of an agreement1 between the Commission and CEN, to transfer the preparation and the publication of In 1989, the Commission and the Member States of the EU and EFTA decided, on the basis of an agreement 2 between the Commission and CEN, to transfer the preparation and the publication of 2 Agreement 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). 7

10 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 Council s Directives and/or Commission s Decisions dealing with European standa rds (e.g. the Council Directive 89/106/EEC on construction products - CPD and on Council Directives 2004/17/EC and 2004/18/EC on public works and services and equivalent EFTA Directives initiated in pursuit of setting up the internal market). the Eurocodes to CEN through a series of Mandates, in order to provide them with a status of European Standard (EN) at the end of the development process. This links de facto the Eurocodes with the provisions of all the Council s Directives and/or Commission s Decisions dealing with European standards (e.g. the Council Directive 89/106/EEC on construction products - Construction Product Directive CPD replaced by the Regulation (EU) N 305/2011 Construction Product Regulation (CPR) and Council Directive 2004/17/EC and 2004/18/EC 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 : Basis 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: 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 The Structural Eurocode programme 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 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: 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 8

11 Eurocode standards recognise 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. [N.B. New Eurocodes or Eurocode Parts will be added later] Eurocode standards recognise 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 and 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 N 1 Mechanical resistance and stability and Essential Requirement N 2 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 construction works themselves, have a direct relationship with the Interpretative Documents2 The Member States of the EU and EFTA recognise that Eurocodes serve as reference documents for the following purposes: to prove compliance of building and civil engineering works or parts thereof with the Basic Requirement for Construction Works N 1 Mechanical resistance and stability, a part of the Basic Requirement for Construction Works N 2 Safety in case of fire and a part of Basic Requirement for Construction Works N 7 Sustainable use of natural resources; as defined in Annex I of the Regulation No.305/2011 as a basis for specifying contracts for construction works and related engineering Services expressing in technical terms, the Basic Requirement for Construction Works applicable to the works and parts thereof; as normative reference standards for drawing up harmonised technical specifications for This clause has been altered so that it is in accordance with the CPR. References to essential requirements are replaced by Basic Requirement for Construction Works In accordance with the CPR reference is made to CEN Technical Committees and/or TAB (Technical Assessment Bodies) Working Groups working on harmonised technical specifications. Based on a decision made at the CEN/TC250 meeting in Berlin on 2 to 3 May 2012 the reference to Essential Requirement No 4 Safety in 9

12 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 considered by CEN Technical Committees and/or EOTA Working Groups working on product standards and ETAGS with a view to achieving a 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 and parts of works and structural construction products of both a traditional and an in-novative 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. structural construction products (ENs and ETAs) and determining the performance of structural components and kits with regard to mechanical resistance and stability and resistance to fire, insofar as it is part of the information of the declaration of performance and CE-marking (e.g. declared values or classes). Technical aspects arising during the development of the Eurocodes need to be adequately considered by CEN Technical Committees and/or TAB (Technical Assessment Bodies) Working Groups working on harmonised technical specifications in order to achieve 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 and parts of works and structural construction products of both a traditional and an innovative nature. Some types of Construction Works (e.g. nuclear structures, large dams) or design conditions that are not specifically covered will require additional provisions and additional expert consideration by the designer. Use has been removed. (N.B. This had already been removed in the last revision) To provide increased clarity Unusual forms of construction or design conditions are not specifically covered and additional expert consideration will be required by the designer in such cases. has been replaced by Some types of Construction Works (e.g. nuclear structures, large dams) or design conditions that are not specifically covered will require additional provisions and additional expert consideration by the designer. 10

13 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 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 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, values 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, references to non-contradictory complementary information to assist the user to apply the Eurocode. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause 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 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, values 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, references to non-contradictory complementary information to assist the user to apply the Eurocode. recommendation Minor editorial changes only here. 11

14 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Links between Eurocodes and harmonised technical specifications (ENs and ETAs) for products Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation There is a need for consistency between the harmonised technical specifications for construction products and the technical provisions for works. Furthermore, all the information accompanying the CE Marking of the construction products which use the Euro- codes shall clearly mention which Nationally Determined Parameters have been taken into account. There is a need for consistency between the harmonised technical specifications for structural construction products and the technical provisions for works. Furthermore, all the information in the declaration of performance of the construction products which refer to the Eurocodes shall clearly mention which Nationally Determined Parameters have been taken into account. Wording changed as appropriate to be in accordance with the CPR Additional information specific to EN 1990 EN 1990 describes the Principles and requirements for safety, serviceability and durability of structures. It is based on the limit state concept used in conjunction with a partial factor method. For the design of new structures, EN 1990 is intended to be used, for direct application, together with Eurocodes EN 1991 to EN 1990 also gives guidelines for the aspects of structural reliability relating to safety, serviceability and durability : for design cases not covered by EN 1991 to EN 1999 (other actions, structures not treated, other materials) ; to serve as a reference document for other CEN TCs concerning structural matters. EN 1990 is intended for use by : committees drafting standards for structural EN 1990 describes the Principles and requirements for safety, robustness, serviceability and durability of structures. It is based on the limit state concept used in conjunction with a partial factor method. For the design of new structures, EN 1990 is intended to be used, for direct application, together with the whole set of the Eurocodes. EN 1990 also gives guidelines for the aspects of structural reliability relating to safety, serviceability and durability: for design cases not covered by the whole set of the Eurocodes (other actions, structures not treated, other materials); to serve as a reference document for other CEN TCs concerning structural matters. EN 1990 is intended for use by: committees drafting standards for structural Robustness has been added in the 1 st paragraph. Eurocodes EN 1991 to 1999 has been replaced as appropriate by the whole set of the Eurocodes in anticipation of new Eurocodes on glass etc.. 12

15 design and related product, testing and execution standards ; clients (e.g. for the formulation of their specific requirements on reliability levels and durability) ; designers and constructors ; relevant authorities. EN 1990 may be used, when relevant, as a guidance document for the design of structures outside the scope of the Eurocodes EN 1991 to EN 1999, for : - assessing other actions and their combinations ; - modelling material and structural behaviour ; - assessing numerical values of the reliability format. Numerical values for partial factors and other reliability parameters are recommended as basic values that provide an acceptable level of reliability. They have been selected assuming that an appropriate level of workmanship and of quality management applies. When EN 1990 is used as a base document by other CEN/TCs the same values need to be taken. design and related product, testing and execution standards; clients (e.g. for the formulation of their specific requirements on reliability levels and durability); designers and constructors; relevant authorities. EN 1990 may be used, when relevant, as a guidance document for the design of structures outside the scope of the Eurocodes EN 1991 to EN 1999, for: assessing other actions and their combinations; modelling material and structural behaviour; assessing numerical values of the reliability format. Numerical values for partial factors and other reliability parameters are recommended as basic values that provide an acceptable level of reliability. They have been selected assuming that an appropriate level of workmanship and of quality management applies. When EN 1990 is used as a base document by other CEN/TCs the same values need to be taken. 13

16 Clause National annex for EN 1990 EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 This standard gives alternative procedures, values and recommendations for classes with notes indicating where national choices may have to be made. Therefore the National Standard implementing EN 1990 should have a National annex containing all Nationally Determined Parameters to be used for the design of buildings and civil engineering works to be constructed in the relevant country. National choice is allowed in EN 1990 A1 through National choice is allowed in EN 1990 A2 through Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause This standard gives alternative procedures, recommendations for values and classes with notes indicating where national choices may have to be made. Therefore the National Standard implementing EN 1990 should have a National Annex containing all Nationally Determined Parameters to be used for the design of buildings and civil engineering works to be constructed in the relevant country. National choice is allowed in EN 1990 A1 through National choice is allowed in EN 1990 A2 through recommendation National choice is allowed in EN 1990 A3 through National choice is allowed in EN 1990 A4 through National choice is allowed in EN 1990 A5 through (This chapter should be revised when the content of the revised EN 1990 is known) 14

17 Section 1 General Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation 1.1 Scope 1.1 (1) No change 1.1 (2) No change 1.1 (3) No change 1.1 (4) No change 1.2 Normative references Assumptions 1.3 (1) 1.3 (2) No change: Additionally if new Eurocode standards (e.g. glass, frp etc are cited in normative clauses in the new EN 1990 they have to be added to the list EN 1990 to EN 1999 No change No change 15

18 Clause New 1.3 (3) EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause (3) Further to the general assumptions in (2) the structure is assessed and selected with due regard to the relevant requirements to sustainability in e.g. recyclability, durability and use of environmentally compatible materials. recommendation The background for adding the (3) is Basic Works requirement No 7 which states 7. Sustainable use of natural resources The construction works must be designed, built and demolished in such a way that the use of natural resources is sustainable and ensure the following: (a) recyclability of the construction works, their materials and parts after demolition; (b) durability of the construction works; (c) use of environmentally compatible raw and secondary materials in the construction works. Sustainability is a major concern, involved in most human activities. On the level of standardization this matter is dealt with in CEN by CEN TC 350. How to handle sustainability on a Global, European and national level is still not settled. By the time of the next revision of EN 1990, hopefully basic principles and methodology are agreed in such a manner that it is mature for standardisation, and how to implement references to it in EN 1990 has become clear. The scope of EN 1990 is to define the basic principles applicable for design for "safety", it is not the scope of EN 1990 to define the basic principles for "sustainability", but it is pertinent for EN 1990 to refer and relate to such requirements. 16

19 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April Distinction between Principles and Application Rules 1.4 (1) 1.4 (2) 1.4 (3) 1.4 (4) 1.4 (5) 1.4 (6) 1.5 Terms and definitions Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause No change No change No change No change No change No change 1.5 No change except for Clause see below). Additionally if new Eurocode standards (e.g. glass, frp etc are cited in normative clauses in the new EN 1990 it may be necessary to add some new term and definitions. recommendation 17

20 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 characteristic value of an action (F k ) principal representative value of an action NOTE In so far as a characteristic value can be fixed on statistical bases, it is chosen so as to correspond to a prescribed probability of not being exceeded on the unfavourable side during a "reference period" taking into account the design working life of the structure and the duration of the design situation. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause characteristic value of an action (F k ) principal representative value of an action NOTE In so far as a characteristic value can be fixed on statistical bases, it is chosen so as to correspond to a prescribed probability of not being exceeded on the unfavourable side. during a "reference period" taking into account the design working life of the structure and the duration of the design situation. recommendation The deleted part was causing confusion to practitioners. 1.6 Symbols 1.6 No change. Additionally if new Eurocode standards (e.g. glass, frp etc are cited in normative clauses in the new EN 1990 it may be necessary to add some new symbols. 18

21 Section 2 Requirements Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April Basic requirements 2.1 (1)P Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause No change recommendation 2.1 (2)P 2 (P) A structure shall be designed to have adequate : structural resistance, serviceability, and durability. (2)P A structure shall be designed to have adequate : structural resistance, robustness serviceability, and durability and to comply with the assumptions for sustainability. See 1.3(3) Robustness has been added to the list as its adequacy is essential. Although there is not yet consolidated methods and fully harmonized approaches for dealing with sustainability during design the principles and importance should be stated. (from SL) What we can require is that the structure, system, materials etc. is in accordance with the sustainability assessment forming the basis for the selection of construction, and obtaining the approvals or alike that will form the future system. 2.1 (3)P No change 19

22 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April (4)P 2.1 (5)P Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause No change No change recommendation 2.1 (6) No change 2.1 (7) (7) The provisions of Section 2 should be interpreted on the basis that due skill and care appropriate to the circumstances is exercised in the design, based on such knowledge and good practice as is generally available at the time that the design of the structure is carried out. 2.1(7)P The provisions of Section 2 presuppose that the design is carried out with the necessary skill and care appropriate to the circumstances of the design. The criteria in Section 2 shall be interpreted in the light of the knowledge and good practice that are available at the time that the design of the structure is carried out. N.B. Those involved in design and the Insurance Industry, have asked whether this clause 2.1(7) could be reworded to make it a Principle. New 2.1 (8)P (8)P The design shall be documented with calculations and drawings that are clear, legible and easy to check. The objective of the proposed Clause 2.1 (8)P The design shall be documented with calculations and drawings that are clear, legible and easy to check is to ensure that the design information is correctly conveyed to the contractor, checking authority, client etc. 20

23 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April Reliability Management 2.2 (1)P Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause No change recommendation 2.2 (2) (2) Different levels of reliability may be adopted inter alia : for structural resistance; for serviceability. (2) Different levels of reliability may be adopted inter alia : for structural resistance; for serviceability. 2.2 (3) No change NOTE 1 Guidance may be given in the National annex with regard to quality management measures, reliability differentiation and the use of the provisions dealt with in Annex B. NOTE 2 Reliability differentiation rules have been specified for particular aspects in the design Eurocodes. The background to the proposed changes to this Clause are for A more formal link between 2.2 and Annex A 2.2 (4) No change 21

24 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 (5) The levels of reliability relating to structural 2.2 (5) resistance and serviceability can be achieved by suitable combinations of: a) preventative and protective measures (e.g. implementation of safety barriers, active and passive protective measures against fire, protection against risks of corrosion such as painting or cathodic protection); b) measures relating to design calculations: representative values of actions; the choice of partial factors; c) measures relating to quality management; d) measures aimed to reduce errors in design and execution of the structure, and gross human errors; e) other measures relating to the following other design matters: the basic requirements; the degree of robustness (structural integrity); durability, including the choice of the design working life; the extent and quality of preliminary investigations of soils and possible environmental influences; the accuracy of the mechanical models used; the detailing; f) efficient execution, e.g. in accordance with execution standards referred to in EN 1991 to EN g) adequate inspection and maintenance according to procedures specified in the project documentation. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause (5) The levels of reliability relating to structural resistance and serviceability can be achieved by suitable combinations of: a) preventative and protective measures (e.g. implementation of safety barriers, active and passive protective measures against fire, protection against risks of corrosion such as painting or cathodic protection); b) measures relating to design calculations: representative values of actions; the choice of partial factors; NOTE See also Annex B c) measures relating to quality management; NOTE See also Annex B d) measures aimed to reduce errors in design and execution of the structure, and gross human errors; NOTE See also Annex B e) other measures relating to the following other design matters: the basic requirements; the degree of robustness (structural integrity); durability, including the choice of the design working life; the extent and quality of preliminary investigations of soils and possible environmental influences; the accuracy of the mechanical models used; the detailing; f) efficient execution, e.g. in accordance with execution standards referred to in EN 1991 to EN g) adequate inspection and maintenance according to procedures specified in the project documentation. recommendation The background to the proposed changes to b) c) and d) in this Clause are for A more formal link between 2.2 and Annex A 22

25 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April Design working life 2.3 (1) (1) The design working life should be specified. NOTE Indicative categories are given in Table 2.1. The values given in Table 2.1 may also be used for determining time-dependent performance (e.g. fatigue-related calculations). See also Annex A. Table Indicative design working life Indicative Examples design working life (years) Design working life category 1 10 Temporary structures (1) 2 10 to 25 Replaceable structural parts, e.g. gantry girders, bearings 3 15 to 30 Agricultural and similar structures 4 50 Building structures and other common structures Monumental building structures, bridges, and other civil engineering structures (1) Structures or parts of structures that can be dismantled with a view to being re-used should not be considered as temporary. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause (1)P The design working life shall be specified, and be the basis for appropriate items including the durability design and the basis for sustainability evaluations (see 1.3(3) and life cycle considerations. NOTE Indicative categories are given in Table 2.1. The values given in Table 2.1 may also be used for determining time-dependent performance (e.g. fatigue-related calculations). See also Annex A. Table Indicative design working life Indicative Examples design working life (years) Design working life category 1 10 Temporary structures (1) 2 10 to 25 Replaceable structural parts, e.g. gantry girders, bearings 3 15 to 30 Agricultural and similar structures 4 50 Building structures and other common structures Monumental building structures, bridges, and other civil engineering structures (1) Structures or parts of structures that can be dismantled with a view to being re-used should not be considered as temporary. recommendation The background for additional information for this Clause is to present useful additional information on the importance of the design working life. The proposal is for paragraph (1) to become a principle, stating that the design working life shall be used for the durability design, and the basis for sustainability and Life Cycle considerations. (N.B. Note that for construction products "reference life" is a parameter that is used, for structures designed with durability according to the Eurocodes, the design working life could have this function, or actually even better as it considers the structure in its actual environment.) 23

26 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April Durability 2.4 (1) P (1)P The structure shall be designed such that deterioration over its design working life does not impair the performance of the structure below that intended, having due regard to its environment and the anticipated level of maintenance. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause (1)P The structure shall be designed such that deterioration over its design working life does not impair the performance of the structure below that intended, having due regard to its environment and the anticipated level of maintenance. recommendation The background for this minor amendment is to clarify that durability of structures are however a designed property and not a tested property. NOTE Durability is an essential parameter when assessing sustainability, durability of structures are however a designed property and not a tested property like for many construction products. This note is added to reflect that durability is a vital part of sustainability, in the BWR7 of the CPR. (Note however that in EN 1990 context durability is a requirement in order to maintain structural safety, as we have no allowance for deterioration in our design procedures.) 2.4 (2) 2.4 (3)P 2.4 (4) No change No change No change 24

27 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April Quality management 2.4 (1) (1) In order to provide a structure that corresponds to the requirements and to the assumptions made in the design, appropriate quality management measures should be in place. These measures comprise: definition of the reliability requirements, organisational measures and controls at the stages of design, execution, use and maintenance. NOTE EN ISO 9001:2000 is an acceptable basis for quality management measures, where relevant. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause (1) In order to provide a structure that corresponds to the requirements and to the assumptions made in the design, appropriate quality management measures should be in place. These measures comprise: definition of the reliability requirements, organisational measures and controls at the stages of design, execution, use and maintenance. NOTE EN ISO 9001:2000 is an acceptable basis for quality management measures, where relevant, it may however have to be supplemented with requirements relevant for the particular design or execution as appropriate. See Annex B. recommendation This recommendation recognises that EN ISO 9001 may not give adequate guidance in relation to design and execution of construction works and a reference to Annex B of EN 1990 has been made. 25

28 Section 3 Principles of limit states design Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation 3.1 General 3.1(1)P No change 3.1(2) No change 3.1(3) No change 3.1(4) No change 3.1(5) Verification of limit states that are concerned with time dependent effects (e.g. fatigue) should be related to the design working life of the construction. 3.2 Design Situations NOTE Most time dependent effects are cumulative. Verification of limit states that are concerned with time dependent effects (e.g. fatigue) should be related to the design working life of the construction. NOTE 1 Most time dependent effects are cumulative. NOTE 2 For fatigue verifications of replaceable structural parts it is possible to consider a reduced design working life, provided that the replacement is explicitly taken into account in the design. To clarify the concept of design working life and of replaceable parts. 3.2(1)P No change 3.2(2)P No change 26

29 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April (3)P No change 3.3 Ultimate Limit States 3.3(1)P No change 3.3(2) No change 3.3(3) No change Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation recommendation 3.3(4)P No change An Appendix includes the proposal for a re-arrangement of the ULS list, consistently with changes proposed in Section 6 and Annex A1. Clause 3.4 Serviceability Limit States EN 1990: A1:2004 incorporating corrigenda December 2008 and April (1)P No change 3.4(2)P No change 3.4(3) No change 3.5 Limit State Design 3.5(1)P No change Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation 27

30 3.5(2)P No change 3.5(3)P No change 3.5(4) No change 3.5(5) No change 3.5(6)P No change 3.5(7) No change 3.5(8)P No change 3.5(9) No change 28

31 Section 4 Basic Variables Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April Actions and environmental influences Classification of actions Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation 4.1.1(1)P No change 4.1.1(2) No change 4.1.1(3) No change 4.1.1(4)P No change 4.1.1(5) No change Characteristic values of actions 4.1.2(1)P No change 4.1.2(2)P No change 29

32 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April (3) The variability of G may be neglected if G does not vary significantly during the design working life of the structure and its coefficient of variation is small. G k should then be taken equal to the mean value. Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause The variability of G may be neglected if G does not vary significantly during the design working life of the structure and its coefficient of variation is small. G k should then be taken equal to the mean value. recommendation NOTE This coefficient of variation can be in the range of 0,05 to 0,10 depending on the type of structure. NOTE Generally the coefficient of variation may be considered small if it is not greater then 0,10, except for members or structures subject to overturning or uplift (EQU and UPL, see section 6), when it may be considered small if it is not greater than 0,05. Provide guidance on the use of G k,inf and G k,sup 4.1.2(4) No change 4.1.2(5) The self-weight of the structure may be represented by a single characteristic value and be calculated on the basis of the nominal dimensions and mean unit masses, see EN NOTE For the settlement of foundations, see EN Where the self-weight of the structure may be represented by a single characteristic value, this may be calculated on the basis of the nominal dimensions and mean unit masses, see EN NOTE For the settlement of foundations, see EN Align the rules with the previous treatment of variability of G (6) No change 4.1.2(7)P No change 4.1.2(8) No change 30

33 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April (9) No change 4.1.2(10) No change Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause recommendation 4.1.2(11) Material properties to be used in first and second order non-linear analyses may either be based on design values, characteristic values, or mean values provided a consistent safety concept is used, that provide the same reliability as intended by the use of conventional design methods. Details for how non-linear analyses may be performed for the various construction materials are given in EN 1992 to EN New clause, to implement rules specific to non linear analysis Other representative values of variable actions 4.1.3(1)P No change Representation of fatigue actions 4.1.4(1) No change 31

34 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April (2) For structures outside the field of application of models established in the relevant Parts of EN 1991, fatigue actions should be defined from the evaluation of measurements or equivalent studies of the expected action spectra. NOTE For the consideration of material specific effects (for example, the consideration of mean stress influence or non-linear effects), see EN 1992 to EN Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause For structures outside the field of application of models established in the relevant Parts of EN 1991, fatigue actions should be defined from the evaluation of measurements or equivalent studies of the expected action spectra. NOTE 1 For the consideration of material specific effects (for example, the consideration of mean stress influence or non-linear effects), see EN 1992 to EN1995, EN 1998 and EN NOTE 2 For bridges simplified fatigue verifications may be performed using the Damage equivalent coefficient method (λ-method) according to EN 1992 to EN 1995, EN 1998 and EN 1999, where relevant, following the scheme given in the informative Annex.) recommendation To provide a common basis to λ-method as well as to λ- coefficient given in different ENs, especially in terms of calibration of λ-values. At present different backgrounds are provided in different ENs. Note: In case the proposal is agreed, a short Annex should be prepared where precise guidance is provided to calibrate different λ-values, providing appropriate definitions for each of them. 32

35 Clause EN 1990: A1:2004 incorporating corrigenda December 2008 and April 2010 Recommendations for the evolution of EN 1990 and notice of future possible changes to Clause 4.1.4(3) (3) The fatigue load models in EN 1991 include effects of accelerations caused by the actions, either implicitly in the equivalent and frequent fatigue load values, or explicitly by applying dynamic enhancement factors to fatigue loads Representation of dynamic actions recommendation New Clause, to clarify the significance of the load values in fatigue load models 4.1.5(1) The load models defined by characteristic values, and fatigue load models, in EN 1991 may include the effects of accelerations caused by the actions either implicitly or explicitly by applying dynamic enhancement factors. (1) The load models defined by characteristic values, and fatigue load models, in EN 1991 may include the effects of accelerations caused by the actions either implicitly in the given load values or explicitly by applying dynamic enhancement factor to static and fatigue loads. To make the clause more precise Geotechnical actions NOTE Limits of use of these models are described in the various Parts of EN NOTE Limits of use of these models are described in the various Parts of EN (1)P No change 33