Call for Tenders - Grant Agreement SA/CEN/GROW/EFTA/515/ Volume 3 - Specification

Transcription

1 Call for Tenders - Grant Agreement SA/CEN/GROW/EFTA/515/ Volume 3 - Specification Request for tenders for 22 project team leaders, up to 88 technical experts and 1 technical reviewer, in response to Mandate M/515 phase 2 tasks for the development of the 2 nd generation of EN Eurocodes Launch: 19 December 2016 Deadline for tenders: 6 February 2017 NEN Vlinderweg AX Delft NL, P.O. Box 5059, 2600 GB Delft +31 (0) M515Eurocodesphase2@nen.nl Page 1/87

2 OVERVIEW OF ALL DOCUMENTS FOR THE CALL FOR TENDERS - GRANT AGREEMENT SA/CEN/GROW/EFTA/515/ The complete list of documents available to Tenderers contains the following elements: Volume 1 (available separately): Instructions to Tenderers This volume provides full instructions on how the Tender Process shall be organized and how and when Tenderers should submit their responses to the questions contained within and to the award criteria; Volume 2 (available separately): Contract terms and Conditions - This Volume contains the documentation for Contracts and general terms and conditions; Volume 3 (this document): The Specification This volume contains the scope/brief, outlining the requirements. Volume 1 Annex 2 (available separately): Template for quality submission This word document provides the template for the quality submission Volume 1 Annex 3 (available separately): Template for financial submission This excel document provides the template for the financial submission All the volumes can be found on Page 2/87

3 Table of contents 1 Background and objectives Structural Eurocodes Objectives of the CEN/TC 250 Work Programme Information about CEN/TC Responsibilities of Chairpersons/Convenors, Project Team Leaders,Project Team Members and Technical Reviewer Collaboration Responsibilities of Chairpersons and Working Group (WG) Convenors Responsibilities of Project Team Leaders Responsibilities of Project Team Members Responsibilities of the Technical Reviewer General requirements Approach to delivery of tasks Phasing of work programme Schedule for delivery Deliverables and completion of tasks Drafting requirements Review of drafts Incorporation of material prepared by others Coordination within CEN/TC Issues arising from liaisons for other Technical Committees Enhancing ease of use Reduction of National Determined Parameters Systematic Reviews Background documents Reporting Meetings Provision of background and supporting information Detailed requirement for tasks Page 3/87

4 5 Terms and definitions Annex A Detailed Task Specifications A.1 Tasks relating to EN 1990: Basis of design (SC10) A.1.1 Task SC10.T2: Evolution of EN1990 General A.2 Tasks relating to EN 1991: Actions (SC1) A.2.1 Task SC1.T2: EN (Snow loads) A.2.2 Task SC1.T3: EN (Wind) A.2.3 Task SC1.T4: EN (Thermal actions) A.2.4 Task SC1.T7: EN (Waves and Currents) A.2.5 Task SC1.T8: EN (Atmospheric icing) A.2.6 Task SC1.T10: EN (Silos and Tanks) A.3 Tasks relating to EN 1992: Concrete (SC2) A.3.1 Task SC2.T2: New Items in EN A.3.2 Task SC2.3: Further new Items in EN , EN , EN A.4 Tasks relating to EN 1993: Steel (SC3) A.4.1 Task SC3.T3: Cold-formed members and sheeting - Revised EN A.4.2 Task SC3.T4: Stability of Plated Structural Elements - Revised EN A.4.3 Task SC3.T5: Harmonisation and Extension of Rules for Shells and Similar Structures - Revised EN and EN A.4.4 Task SC3.T6: Fire design of Steel Structures - Revised EN A.5 Tasks relating to EN 1994: Composite (SC4) A.5.1 Task SC4.T1: Development of rules covering shallow floor construction, and other flooring types using precast concrete elements A.6 Tasks relating to EN 1995: Timber (SC5) A.6.1 Task SC5.T3: Revised Eurocode 5, part A.7 Tasks relating to EN 1996: Masonry (SC6) A.7.1 Task SC6.T1: Revised version of EN A.8 Tasks relating to EN 1997: Geotechnics (SC7) A.8.1 Task SC7.T3: Ground Investigation A.8.2 Task SC7.T4: Foundations, slopes and ground improvement A.8.3 Task SC7.T5: Retaining structures, anchors, and reinforced ground A.9 Tasks relating to EN 1998: Earthquake (SC8) Page 4/87

5 A.9.1 Task SC8.T2: Material independent sections of EN A.9.2 Task SC8.T4: Evolution of EN A.10 Tasks relating to EN 1999: Aluminium (SC9) A.10.1 Task SC9.T3: Long span Structures Annex B CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes B.1 Purpose of this document B.2 Background B.3 Vision: delivering long term confidence B.4 Approach: five pillars to enhance ease of use B.5 Guidelines: realising our ambitions B.5.1 Statements of intent to meet users needs B.5.2 Principles and related priorities B.5.3 Examples B.5.4 Strategic performance measures B.5.5 Management, governance and support B.6 References Annex C CEN/TC 250 Position paper on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes C.1 Purpose of this document C.2 Background C.3 Objectives and governing principles C.4 Approach C.4.1 Step 1: Identification of parameters that must be NDPs C.4.2 Step 2: Review of other NDPs C.4.3 Step 3: Reporting C.5 References Appendix C1 Further background to National Determined Parameters C1.1 Number of NDPs in the current generation of Eurocodes C1.2 Legal basis of NDPs Annex D Timetable D.1 General D.2 Timetable for the delivery of tasks Page 5/87

6 D.3 Standard programmes for drafting work under Mandate M/515 EN Annex E Provisional list of tasks in the complete CEN/TC 250 work programme Annex F Mandate M/ F.1 General Page 6/87

7 1 Background and objectives 1.1 Structural Eurocodes The Eurocodes were developed to enable the design of building and civil engineering works. All 10 of the existing EN Structural Eurocodes, in 58 parts, were published prior to June They comprise: 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 EN Eurocodes have been amended and corrected since their original publication. Any amendments and corrigenda published by CEN should be considered as an integral part of the Eurocodes by the Project Teams. 1.2 Objectives of the CEN/TC 250 Work Programme The objective of the CEN/TC 250 work programme is to fulfil the requirements of EC Mandate M/515 and result in the development and publication of the second generation of EN Eurocodes. It encompasses the development of new standards and new parts of existing standards, and the incorporation of new performance requirements and design methods across multiple standards. The CEN/TC 250 work programme also emphasises the need to enhance the user-friendliness of the Eurocodes. In addition, it includes the preparation of recommendations setting out how the Eurocodes should be adapted to account for the relevant impacts of future climate change. The tasks contained in this Specification form a central component of the CEN/TC 250 work programme. Their successful delivery will be vital to fulfilling CEN/TC 250 s objectives and the requirements of Mandate M/515. A copy of European Commission Mandate M/515 is provided in Annex F. 1.3 Information about CEN/TC 250 Details of structure, business plan and published standards of CEN/TC 250 can be found in the technical bodies section of the CEN website: Page 7/87

8 8519ABE9C The CEN/TC 250 structure includes a Management Group, Coordination Group, 11 Subcommittees (SC), 4 first tier Work Groups (WG) that report directly to TC 250, two Horizontal Groups (HG) and a large number of subordinate Working Groups and Task Groups. One of the CEN/TC 250 Subcommittees, Working Groups or Horizontal Groups has responsibility for overseeing the successfully delivery of each of the task in the TC250 work programme. The current structure of CEN/TC 250 (excluding subordinate Working Groups and Task Groups) is shown in Figure 1. This structure may be subject to change. Figure 1 Current CEN/TC 250 Structure (excluding subordinate Work Groups and Task Groups) The CEN/TC 250 Management Group comprises the Chairman, Vice Chair, Secretary, CEN PM and NEN representative (M/515 Project Leader), M Lurvink. Page 8/87

9 2 Responsibilities of Chairpersons/Convenors, Project Team Leaders,Project Team Members and Technical Reviewer 2.1 Collaboration All members of Project Teams shall work collaboratively and create an environment characterised by mutual trust, fairness, respect, openness and whole team focus on delivering Mandate M/515 and CEN/TC 250 s objectives. Collaborative working is essential because of the high level of interdependency between the Eurocode parts and the tasks in the TC 250 work programme. The Chairman/Convenor and Secretary of the SC / WG or HG responsible for each task will serve as exofficio members of each Project Team, fulfilling a key role in ensuring effective technical coordination and that the work of the Project Team is aligned with the requirements of EC/EFTA and CEN/TC Responsibilities of Chairpersons and Working Group (WG) Convenors As key leaders in the CEN/TC 250 organization structure, the role of Chairmen and Convenors in overseeing and coordinating work done by the Project Teams is be essential to the successful execution of the mandate. Their responsibilities includes: communicating the clear vision and priorities for the evolution of the Eurocodes, agreed with CEN/TC 250, to their SC/WG; supporting the overall leadership and governance framework for the execution of the mandate; ensuring that the work of Project Teams aligns with the objectives of the mandate and the requirements of CEN/TC 250 and the relevant SC/WG; preparation for and chairing meetings of SC / WGs; active participation in CEN/TC 250 plenary and the CEN/TC 250 Coordination Group meetings; participation in Project Teams as an ex-officio member, providing technical leadership when required; review and approval of Project Team progress reports, and agreement of any corrective actions required with CEN/TC Chairman; preparation of SC/WG progress reports, in particular identifying any significant risks to delivery and technical coordination matters requiring resolution; technical review of draft deliverables; and, participation in meeting as required to support the execution of the mandate and ensure effective coordination of cross-cutting issues. Page 9/87

10 2.3 Responsibilities of Project Team Leaders The Project Team Leader shall: lead the Project Team and coordinate the input from its members; communicate the vision and priorities for the evolution of the Eurocodes, agreed with CEN/TC 250, to their Project Team; ensure that the work of the Project Team aligns with the objectives of Mandate M/515 and the requirements of CEN/TC 250 and the relevant Subcommittee (SC), Working Group (WG) or Horizontal Group (HG); plan the delivery of the task and drive delivery to programme; organize and chair (face-to-face and online) meetings of the Project Team; present and discuss the result of the work within the responsible SC/WG or HG, when required; evaluate and report on comments received from SC/WG/HG or through the enquiry process; review and incorporate proposals from the SC/WG/HG in the drafts, ensuring consistency and coherence with the rest of the draft; and prepare progress and final reports. The Project Team Leader shall inform NEN of any event or risk liable to substantially affect the contribution of the Project Team to the CEN/TC 250 work programme and/or delay delivery to the required timetable. 2.4 Responsibilities of Project Team Members Project Team members will be recognized experts who collectively provide the portfolio of skills and knowledge required to successful deliver each Project Team s task. They will be responsible for working together and with the Project Team Leader to deliver the task requirements and support the Project Team Leader in fulfilling the Project Team Leader s responsibilities. Project Team Members shall work proactively, collectively and collaboratively to: agree individual assignments and responsibilities within the Project Team; provide new technical draft texts, or corrections and/or amendments to existing texts for inclusion in the next generation of the Structural Eurocodes; provide contributions to background reports providing justification for technical choices made within the draft texts; provide suggestions and justification for the reduction of National Determined Parameters (NDPs); provide suggestions for the enhancement of the ease of use of the next generation of Eurocodes; Page 10/87

11 ensure that the work of Project Team aligns with the objectives of Mandate M/515 and the requirements of CEN/TC 250 and the relevant Subcommittee (SC), Working Group (WG) or Horizontal Group; plan the delivery of those parts of the task assigned to them and achieve delivery to programme; when requested and agreed, present and discuss the result of the work within the responsible SC/WG/HG; evaluate and report on comments received from SC/WG/HG or through the enquiry process; review and incorporate proposals from the SC/WG/HG in the drafts, ensuring consistency and coherence with the rest of the draft; and contribute to progress and final reports. Project Team Members shall inform the Project Team Leader of any event or risk liable to substantially affect or delay the delivery of the task. 2.5 Responsibilities of the Technical Reviewer In support of the key objective of enhancing the ease of use of the Eurocodes, it is essential that a high degree of technical coordination is undertaken to promote consistency between Eurocode parts. Relevant matters include notation, terminology, document structures, drafting styles and some crosscutting technical approaches. To meet this need, a Technical Reviewer will be appointed to scrutinize reports and drafts and develop recommendations to improve consistency and enhance the ease of use of the Eurocodes. The Technical Reviewer will work closely with, and under the direction of the CEN/TC 250 Chairman. The Technical Reviewer will have experience in the application and development of the Eurocodes and be wholly familiar with CEN/TC 250 s strategy for enhancing the ease of use of the Eurocodes. The Technical Reviewer shall: review draft technical deliverables (primarily prepared by the Project Teams) and make recommendations to enhance consistency between different Eurocode parts and improve ease of use; develop guidance materials and briefings to support the work of CEN/TC 250 and the Project Teams in meeting the objectives of mandate M/515; maintain an overall library of notation and terminology usage, highlight areas where consistency could be enhanced; The Technical Reviewer shall inform NEN of any event or risk liable to substantially affect the CEN/TC 250 work programme and/or delay delivery to the required timetable, within his or her direct influence and beyond. Page 11/87

12 3 General requirements This section sets out general requirements for the Project Team Leaders and Project Team Members. 3.1 Approach to delivery of tasks At the start of each task the Project Team Leader shall prepare a detailed work plan for the delivery of the task based on the requirements of this Specification. This shall be done in conjunction with the Project Team Members. The work plan shall be agreed with Chairman/Convenor of the SC, WG or HG responsible for the task. The work plan may include the need for the prioritisation of some activities and shall account for interdependencies between tasks. The detailed work plan shall include the assignment of responsibilities to individual Project Team members. Copies of the work plans shall be provided to NEN within 6 months of the appointment of the Project Team. Any general queries arising from the preparation of the work plan shall be referred to the CEN/TC 250 management group to enable a consistent response to be provided to all Project Teams. During the delivery of the task, the Chairman/Convenor of the SC, WG or HG responsible for the task shall agree any changes necessary to the work plan with the Project Team Leader. Any changes to the work plan shall be notified to NEN. The Project Team shall accept reasonable requests to modify their approach or undertake actions from the Chairman/Convenor of the SC, WG or HG responsible for the task necessary to fulfil CEN/TC 250 s objectives and/or the requirements of Mandate M/515. In the event that the Project Team considers a request from the responsible Chairman/Convenor to be unreasonable or unduly disruptive to other work they shall notify NEN. 3.2 Phasing of work programme The CEN/TC 250 work programme has been split into four over-lapping phases, as illustrated Figure 2. This has been done to enable the interdependencies between activities to be effectively managed, and ensure that the work is undertaken as efficiently as possible. Page 12/87

13 Figure 2 Indicative phasing of the work This specification concerns the tasks in Phase 2. However, Project Teams will need to undertake their work in anticipation of how it will be used by or affect the work of Project Teams undertaking tasks in earlier or later phases of the work programme. This shall be considered in the work plan for each task. For information, a provisional list of the tasks included in all phases of the work programme is provided in Annex E. 3.3 Schedule for delivery The timetable for delivery is given in Annex D. In accordance with the agreement with EC/EFTA, all work in Phase 2 of the work programme must be concluded within 42 months of 1 January The work plan for each task shall be consistent with the timetable presented in Annex D unless otherwise agreed with NEN and the CEN/TC 250 Management Group. 3.4 Deliverables and completion of tasks A summary of deliverables is provided in Table 1 of Volume 1 of this Call for Tenders. Project teams responsibilities will end when they have provided a draft that EC/EFTA accepts as being a correct and adequate response to the Contract. Technical approval for the work of the Project Team will come from the relevant CEN/TC 250 Subcommittee, Working Group or Horizontal Group The deliverables for all tasks will undergo an enquiry (either formal or informal) prior to the completion of the task, enabling CEN members to provide comment. The Project Team shall be responsible for addressing these comments and providing a commentary on the actions taken and reasoning, prior to completing their work. 3.5 Drafting requirements Drafting shall comply with the CEN Internal Regulations Part 3 (IR3), which can be found at (EN,GE, FR), as modified or extended by any derogations granted to CEN/TC 250 and by the guidelines provided in CEN/TC 250 document N1250. Page 13/87

14 CEN/TC 250 document N1250 is currently being finalised and will be made available to Project Teams to assist them in their work and promote consistency of style (e.g. numbering of figures and tables, use of clause numbering, common headings, etc.). It will include examples where appropriate. It may be updated periodically if further clarification to Project Teams is found to be necessary. MS Word format (versions 2010 or 2013) shall be used for the preparation of document draft. It is the file format in use by CEN and the National Standardization Bodies (NSBs). The preferred file type for images and drawings is DWG (2D only, versions 2007, 2010, 2013). The DWG file type is to be used by contractors because in compliance with of IR3 figures shall be in the form of line drawings. A copy of the plotted final figure shall be provided in PDF file type for reference and comparison purposes. More information on images and drawings can be found on material/guidancedoc/pages/enelecprep.aspx. 3.6 Review of drafts The SC, WG or HG responsible for each task may delegate responsibilities for the review of draft deliverables to subordinate Working Groups or Task Groups. Subordinate Working Group and Task Groups may also be available to support the Project Team in undertaking their work, as agreed with the relevant SC Chairman or WG/HG Convenor. 3.7 Incorporation of material prepared by others Preliminary material for some elements of some tasks (i.e. for some subtasks) has already been prepared or will be prepared. In such cases, the Project Team shall review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. 3.8 Coordination within CEN/TC 250 Effective horizontal coordination will be crucial to ensure that technical and structural consistency is achieved in the next generation of Eurocodes. Overall responsibility for horizontal coordination will remain with the CEN/TC 250 Coordination Group, supported by the existing Horizontal Groups for Bridges and Fire. Project Teams shall work collaboratively to achieve consistency across the Eurocode Parts and shall accept direction from the CEN/TC 250 Coordination Group necessary to achieve consistency. 3.9 Issues arising from liaisons for other Technical Committees The CEN Technical Board has reaffirmed that product and execution standards for use within the construction sector should refer to the relevant Eurocodes for structural and geotechnical design rules where needed. CEN/TC 250 has been requested to contact other CEN/TCs to liaise and collaborate to transpose design rules to the relevant Eurocodes, or as a minimum eliminate any incompatibilities or Page 14/87

15 ambiguities. Although these liaisons are generally handled by CEN/TC 250 Subcommittees, it may be necessarily for Project Team Members to consult with members of other CEN/TCs so that specific technical topics can be correctly addressed and included within their deliverables Enhancing ease of use CEN/TC 250 is committed to enhancing ease of use in the development of the Eurocodes. Based on the work of a CEN/TC 250 Chairman s Advisory Panel, a position paper on enhancing the ease of use of the Eurocodes has been unanimously agreed by CEN/TC 250 members to guide decision making during the development of the second generation of EN Eurocodes. This position paper is included in Annex B. All tasks in the work programme include a requirement to work to improve the ease of use of existing Eurocode parts and ensure that new parts are drafted with an emphasis on ease of use, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements Reduction of National Determined Parameters Nationally Determined Parameters (NDPs) allow Countries to decide on safety levels, and to give national geographic and climatic data, in National Annexes. The inclusion of NDPs in the published Eurocodes has been more extensive than was originally envisaged. All tasks concerned with existing Eurocode parts include a requirement to work to reduce the number of NDPs and enable better consensus on values adopted by Countries. A position paper on the approach to be taken has been unanimously agreed by CEN/TC 250 members to guide decision making during the development of the second generation of EN Eurocodes. This position paper is included in Annex C. It is expected that the work of Project Teams will be focussed only on a proportion of the existing NDPs, as identified and agreed with the relevant SC, WG or HG Systematic Reviews Part of the CEN procedure is to hold 5 year reviews of their standards. It was realised in 2008 that to send out the 58 parts of the Eurocodes for review 5 years after their publication dates would be of little value as they would not have been exposed to widespread practical application. The CEN Technical Board (BT) agreed a derogation for CEN/TC 250, allowing certain of the normal rules to be relaxed, including the need for the review at 5 years. Systematic 5 year reviews have now been undertaken for all of the Eurocode parts relevant to the tasks in Phase 2 of the work programme. The relevant SC has reviewed the comments received and categorised them. Those comments relevant to the tasks in this Specification may be passed to the relevant Project Team for action. Project Teams may also need to incorporate new or modified material into their deliverables that has been prepared by others arising from comments made during the systematic reviews. Page 15/87

16 3.13 Background documents It is a requirement of CEN/TC 250 that all future work, including revisions to existing parts and preparation of new parts, will be accompanied by background documents. These background documents shall serve as a technical audit trail to decisions taken in the standardisation process and will be made available via the TC 250 (livelink) database of numbered documents, so that they will be accessible by members of TC250 family of sub-committees and working groups. They will also be available to national mirror committees via their NSB to assist in the development of new National Annexes to the second generation of Eurocodes. The Project Teams shall therefore prepare background reports providing a brief technical commentary to any new or revised clauses including clear references to relevant source papers, reports, national standards etc. These documents should serve as working documents during the standardisation process and a record for the future. Specifically: Background reports shall explain the technical reasons for all decisions to change the Eurocodes from the current published versions or introduce new material. The level of detail provided should be commensurate with the complexity of the decision. Where references are made to further detailed background information, such information shall either be publically available or be provided as an annex to the background report. Where reference material does not directly explain the decision taken, additional commentary shall be provided. Where changes are made in response to systematic review comments, the comment reference should be noted. In developing background reports the inclusion of reference to the Ease of Use principles being followed is encouraged. Guidance on the format of these documents will be provided to Project Teams. It is not intended that these reports would be suitable for direct publication, but will provide a valuable source of information for those developing guides, text books or other materials to support industry Reporting Short progress reports shall be sent to NEN and the relevant SC Chairman or WG/HG Convenor by the Project Team Leader at least every two months. A simple template will be provided for this purpose. Every six months a more detailed progress report shall be prepared including the latest working drafts and related material (e.g. background documents, comment sheets, etc.) and submitted to NEN and the relevant SC Chairman or WG/HG convenor. Project Team Members shall assist with the preparation of any of these reports when required by the Project Team Leader. Page 16/87

17 In those cases where the six monthly progress reports will be consolidated by the CEN/TC 250 Management Group for transmission to EC/EFTA (see Annex D), guidance will be provided on the information to be provided by Project Teams. If NEN requires additional information to enable it to fulfil its obligations to CEN and EC/EFTA, Project Team Member shall respond to reasonable requests for information as soon as reasonably possible and not later than 4 weeks after the request is made Meetings Meetings (face-to-face or online) of the Project Team should be organized by the Project Team Leader in collaboration with the relevant SC Chairman, WG or HG Convenor and secretariat in order to maximize effective collaboration. It is envisioned that Project Teams will use modern means of communication and collaborate using , telephone and video-conferencing between face-to-face meetings. Software for videoconferencing (GoToMeeting) can be used free of charge on request at CEN at prior notice, see the CEN website 1 for more information Provision of background and supporting information The Project Teams shall be responsible for gathering background and supporting information necessary for their work. However, relevant Subcommittees, Working Groups and Horizontal Groups and their Subordinate Work Groups and Task Groups may be available to assist in identifying and accessing background and supporting information. 4 Detailed requirement for tasks Detailed requirements for each of the tasks covered by this Specification are included in Annex A. The tasks have been grouped by the Subcommittee, Working Group or Horizontal Group responsible for overseeing them. 1 for Online Meeting software: Page 17/87

18 5 Terms and definitions Within this document the following terms and definitions are used (in alphabetical order). BSI CCMC CEN DAV EC EFTA EN EN FV HG NEN NSB PT SC TC TCA TG TS WG WI British Standards Institution CEN-CENELEC Management Centre European Committee for Standardization Date of availability European Commission European Free Trade Association European Standard European Standard Formal Vote Horizontal Group Dutch Foundation for Standardization National Standards Body Project Team Subcommittee Technical (standardization) Committee TC Approval Task Group Technical Specification Working Group Work Item Page 18/87

19 Annex A Detailed Task Specifications No. Task Relevant SC/WG/HG a Number of tasks in Phase 2 of the CEN/TC 250 Work Programme A.1 Tasks relating to EN 1990: Basis of design SC10 1 A.2 Tasks relating to EN 1991: Actions SC1 6 A.3 Tasks relating to EN 1992: Concrete SC2 2 A.4 Tasks relating to EN 1993: Steel SC3 4 A.5 Tasks relating to EN 1994: Composite SC4 1 A.6 Tasks relating to EN 1995: Timber SC5 1 A.7 Tasks relating to EN 1996: Masonry SC6 1 A.8 Tasks relating to EN 1997: Geotechnics SC7 3 A.9 Tasks relating to EN 1998: Earthquake SC8 2 A.10 Tasks relating to EN 1999: Aluminium SC9 1 Note a WG: CEN/TC 250 Working Group HG: CEN/TC 250 Horizontal Group SC: CEN/TC 250 Subcommittee Page 19/87

20 Detailed Task Specifications - Tasks relating to EN 1990: Basis of design (SC10) A.1 Tasks relating to EN 1990: Basis of design (SC10) There is one task related to EN 1990 in Phase 1 of the CEN/TC 250 work programme. This is: - SC10.T2 Details of this task are provided in the table below. In accordance with CEN/TC 250 Decision 354, SC10 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC10 to subordinate Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC10 and the Project Team. In the first working draft submitted to the WG, tasks considered as first priority by SC 10 will have to be covered. In the second working draft all sub-tasks will have to be included. Page 20/87

21 Detailed Task Specifications - Tasks relating to EN 1990: Basis of design (SC10) A.1.1 Task SC10.T2: Evolution of EN1990 General Task Ref: SC10.T2 Task Name: Evolution of EN1990 Bridges specific issues Outline Task Scope: Starting documents: Revision of EN 1990 to incorporate comments from the EN 1990, 5 year review and requirements from other Eurocodes for principle guidance on fatigue, non-linear analysis etc with the Specific Mandate Section 5 from Mandate for amending existing Eurocodes and extending the scope of structural Eurocodes (Document Doc.28/2012 EN, Brussels, 13th July 2012). In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. EN 1990: Basis of Structural Design; Papers developed through formal liaison between TC 250 Horizontal Group Bridges (HG-B) and TC167, German Annex E; EN 1337 design requirements; Spanish paper (MO) providing illustrations of issues; ETAGs for expansion joints; various National Documents; Various national standards and industry guidance documents related to integral bridges. Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents Interdependencies Related CEN/TC 250 subordinate groups 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Design of integral bridges Integral bridges have become a popular form of construction in many European countries because of their improved durability and the avoidance of expansion joints and some bearings. However, cyclical thermal movements of integral bridge decks lead to enhanced earth pressures behind abutments. Key aspects of the design of integral bridges are not currently addressed in the Eurocodes. National Contacts of HG-B identified the need to develop rules for integral bridges as a priority. Work will draw upon existing national requirements from UK and other countries. 4 Bridge bearings and expansion joints 5 Review and incorporation of recommendations for revisions to EN 1990 Annex A2 developed through other tasks, including fatigue and vibration of footbridges. Aspects of the design of bridge bearings, in particular the appropriate combinations of actions to be used, are not currently well covered in Eurocodes. Liaison has been established with TC 167 to address alignment issues with EN1337. National Contacts to the HG-B have asked for the refinement of design rules for bearings and for the removal of inconsistencies between standards. Several sub-tasks have been included by other groups that will have implications for EN 1990 Annex A2. This sub-task includes for the review of these proposals and incorporation into Annex A2 in a consistent manner to ensure ease of use. Establishment of common rules across Europe for a very common form of structure, which are currently being provided at a National level. Promotion of the use of this form of structure, which can provide significant sustainability benefits in relation to improved durability and reduced delays to travellers due to maintenance works. Address incompatibilities between Eurocodes and with product standards. Establish consistent philosophy to improve ease of use and avoid development of national guidelines to address current deficiencies in Eurocodes. Ensure that proposals are effectively reviewed and incorporated into EN 1990 in a clear and consistent manner. (i) New clauses in Annex A2 to EN 1990 covering treatment of combinations of actions involving earth pressures affected by thermal movement of bridge decks. (ii) Possibly a new informative annex to EN 1997 (prepared under this task for SC7 review / acceptance). Two new Annex Es to EN 1990 Minor modification proposed for EN (removal of content). Removal of content from EN 1993 Fully revised EN 1990 Annex A2 CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes" Work to be undertaken in conjunction with HG-B and SC7 Work to be undertaken in conjunction with HG- B, SC1, SC3 and TC167 Page 21/87

22 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) A.2 Tasks relating to EN 1991: Actions (SC1) There are six tasks related to EN 1991 in Phase 1 of the CEN/TC 250 work programme. These are: - SC1.T2 - SC1.T3 - SC1.T4 - SC1.T7 - SC1.T8 - SC1.T10 Details of these tasks are provided in the tables below. In accordance with CEN/TC 250 Decision 354, SC1 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC1 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC1 and the Project Team. In such cases the first working draft submitted to the SC1 will focused on topics/sub-tasks agreed as first priority. Page 22/87

23 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) A.2.1 Task SC1.T2: EN (Snow loads) Task Ref: SC1.T2 Task Name: EN (Snow loads) Outline Task Scope: Starting documents: Basis for calculation. Collection of available information on the implementation of the ground snow load maps, use and definition of exceptional ground snow loads and improvement of rules for the definition of roof snow loads, with specific regard to the local and global effects and buildings dimensions. Guidance for NAs in view of further harmonization Existing rules of EN , state-of-the-art and NAs Subtask Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents Interdependencies Related CEN/TC 250 subordinate groups 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Ground snow loads Collect snow load on ground based on existing national values and present the values in a snow load map emphasizing differences across borders and revealing the introduction of the exceptional ground snow loads to be dealt with accidental design situations. 4 Snow loads on roofs Shape coefficients; influence of building dimensions (e.g. flat and very large industrial buildings on the basis of current state of the art). Snow deposition patterns and accumulation on different roof structures, e.g. curved roofs and roofs with many local obstructions (on the basis of current state of the art). Influence lines with changing signs. 5 Snow loads; Editorial improvements The collection of available national snow maps allows putting in evidence the differences across borders, to serve as an input to NSBs for the possible further update of their maps, in view of a fully harmonised European snow map. More user friendly Eurocode. Basis for calculation of exceptional snow loads and improved guidance to NSBs to treat these effects in their NAs. Basis for calculation. New basis for treatment of scale effects in large flat buildings. Basis for calculation. Some of the present rules will be improved on the basis of the current state of the art with specific regard to the local and global effects leading to consistent safe calculation procedures. Improvement of EN 1991 through the refinement of NAs towards harmonisation at European scale. Modified clauses Modified clauses. New and modified clauses CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Editorial improvements. More user friendly Eurocode Modified clauses Transfer of some clauses to EN 1990 (Undertaken/already done by SC 10 SC1/WG1 "Climatic actions" SC1/WG1 "Climatic actions" SC1/WG1 "Climatic actions" Page 23/87

24 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) A.2.2 Task SC1.T3: EN (Wind) Task Ref: SC1.T3 Task Name: EN (Wind) Outline Task Scope: Starting documents: Improvement of consistency of the basis for calculations and new basis for calculations. Harmonization of the many different approaches used in the present Eurocodes with National Annexes. Potential harmonization of different Eurocode Parts and CENELEC standards for overhead electric lines, as well as other CEN or ISO standards. Possibly reduction of global wind loads leading to more economical structures. Existing rules of EN , state-of-the-art and NAs Subtask Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents Interdependencies Related CEN/TC 250 subordinate groups 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Wind actions: Wind map 4 Wind actions: Wind models 5 Wind actions: Force and pressure coefficients 6 Wind actions: Dynamic response, vortexinduced vibrations, aeroelastic effects, bridges and response of structures Collect basic wind velocities based on existing national values and present the values in a wind map emphasizing differences across borders Wind models for calculation of wind velocities and peak velocity pressures including roughness categories and transition between roughness categories Systematic review and inclusion of force coefficients as well as internal and external pressure coefficients including influence areas/zoning based on the current state of the art and considering the national and experts comments. The basis will be EN , other Eurocodes Parts, e.g. for towers and masts, chimneys and other structures (e.g. lightweight) together with the wind response of such structures, CENELEC standards and other international codes. Considerations of the usability of the updated structure of Eurocode specifications for specialised structures. Additional rules for vortex-induced vibrations, aeroelastic effects, wind load on bridges and response of structures. Influence lines / mode shapes with changing signs. The collection of available national wind maps allows putting in evidence the differences across borders, to serve as an input to NSBs for the possible further update of their maps, in view of a fully harmonised European wind velocities map. More user friendly Eurocode. Basis for calculations. Harmonization of the many different approaches used in the present Eurocode with National Annexes. EN : Basis for calculation. Harmonization of the many different approaches used in the present Eurocodes with National Annexes. Other Eurocode Parts: establish consistent basis for calculations. Potential harmonization of different Eurocode Parts and CENELEC standards. New basis for calculation. Some of the present rules giving unsafe or uneconomical designs will be replaced by improved and more consistent calculation procedures. New basis for calculation. Consistent approaches leading to more economical structures. New clause New and modified clauses in existing Eurocode Modified clauses Modified clauses. New clauses. CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes SC1/WG1 "Climatic actions" SC1/WG1 "Climatic actions" SC1/WG1 "Climatic actions" SC1/WG1 "Climatic actions" Page 24/87

25 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) 7 Wind actions: Editorial improvements Editorial improvements More user friendly Eurocode Modified clauses Transfer of some clauses to EN 1990 (Undertaken/already done by the EN 1990 EG) - TCEN1990.T1 Page 25/87

26 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) A.2.3 Task SC1.T4: EN (Thermal actions) Task Ref: SC1.T4 Task Name: EN (Thermal actions) Outline Task Scope: Starting documents: Basis for calculations focusing on thermal responses (particularly for bridges) and clarification of the ranges of temperature to be considered. Harmonization across borders. Existing rules of EN , state-of-the-art and NAs Subtask Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents Interdependencies Related CEN/TC 250 subordinate groups 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Thermal actions: Temperature map Collect characteristic temperatures based on existing national values and present the values in a temperature map emphasizing differences across borders. The collection of available national minimum and maximum shade air temperature maps highlights the differences across borders, which then serves as an input to NSBs for the possible further update of their maps, in view of a fully harmonised European minimum and maximum temperature map. More user friendly Eurocode. New clause CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes SC1/WG1 "Climatic actions" 4 Thermal actions: Bearings and joints Characteristic values associated with the design of bearings and joints. Clarification of the ranges of temperature to be considered New clauses SC1/WG1 "Climatic actions" 5 Thermal actions: Overall temperatures and differential temperatures Interdependence of overall temperatures and differential temperatures. Basis for design of structures (particularly bridges) susceptible to combinations of overall temperatures and differential temperatures. Clarification of the combinations related to characteristic values Basis for calculations focusing on thermal responses New clauses 6 Thermal actions: Thermal response, i.e. effects of thermal actions on different structures. New clauses 7 Thermal actions: Editorial improvements. More user friendly Eurocode Modified clauses Editorial improvements SC1/WG1 "Climatic actions" SC1/WG1 "Climatic actions" Page 26/87

27 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) A.2.4 Task SC1.T7: EN (Waves and Currents) Task Ref: SC1.T7 Task Name: EN ( Waves and Currents) Outline Task Scope: Starting documents: Eurocode for Waves and Currents using ISO 21650:2007 as a background document. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. ISO and state-of-the-art Subtask Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Creation of Eurocode Actions from Waves and Currents on coastal structures Creation of Eurocode Waves and current using ISO 21650:2007 as a background/starting document.the main issues to be addressed are : (1) Creation of clauses for Eurocode using the ISO standard as a reference. (2) Considering any additional comments of the stakeholders following consultation (3) Decide whether some of the informative Annexes of the existing document, become normative. (4) Include, if relevant, up-to-date complementary information. As a result the whole package of design of maritime works will become integral part of the Eurocodes family. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents Interdependencies Related CEN/TC 250 subordinate groups New Eurocode Part SC10.T1 SC1/WG6 "Actions from waves and currents on coastal structures" Page 27/87

28 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) A.2.5 Task SC1.T8: EN (Atmospheric icing) Task Ref: SC1.T8 Task Name: EN (Atmospheric Icing) Outline Task Scope: Starting documents: Creation of Eurocode on Atmospheric icing, using ISO 12494:2001 as a starting/background document. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. ISO and state-of-the-art Subtask Ref. 1 Creation of Eurocode on Atmospheric Icing Sub-task name Brief description, background and reasons for the work Key benefits Output The initiative is mainly motivated by the progressive awareness and findings showing the importance of actions on structures due to atmospheric icing, especially for some type of structures (e.g. masts, towers, antennas, cables/ropes etc.) and in particular, but not only, for the Northern European Countries. On the other hand given that an ISO Standard, : 2001 refers to this topic, it is considered appropriate to use this standard as a starting point to create an EN Eurocode. Where possible, more recent established, at an international and national level, research results will be included. An additional issue which should be considered and handled appropriately is the up to now separate development by CLC/TC11 and further evolution of: o EN :2001 Overhead electrical lines exceeding AC 45kV - Part 1: General requirements Common specifications. o EN :2005 Overhead electrical lines exceeding AC 1kV and including AC 45 kv - Part 1: General requirements Common specifications which are closely connected to actions due to atmospheric icing. A known gap will be bridged with the development of actions due to atmospheric icing and their effects on various types of structures. The interdependence with wind actions will also be considered. An attempt will be also made to reach harmonization, as far as possible, with other standards, such as EN and EN (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) New Eurocode Part Further details on reference documents Interdependencies Related CEN/TC 250 subordinate groups SC1.T2, SC1.T3 TCEN1990.T1 SC1/WG2 "Atmospheric icing of structures" Page 28/87

29 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) A.2.6 Task SC1.T10: EN (Silos and Tanks) Task Ref: SC1.T10 Task Name: EN (Silos and Tanks) Outline Task Scope: Starting documents: Rational basis for the reliability assessment of silo loading combinations for different applications in EN 1990 and extension of the various rules for additional types of silos. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. EN , state-of-the-art and NAs Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Transformation of the EN Annex A load cases 4 Pressures on the vertical walls of silos that have an internal inverted cone The reliability of the silo pressure load cases depends on many factors that are currently completely missing from Annex A and its modified versions recently prepared for EN An extended discussion on this substantial problem was recently presented by Nielsen, Rotter and Sorenson (2012). This task involves establishing a new framework of categories on the basis of the descriptions given by Nielsen, Rotter and Sorenson (2012), and finding appropriate combination and partial factors to address each of the features. This will also involve the categorisation of silos according to the relative thickness of the silo walls; the aspect ratio of the silo; whether the silo is on-ground or elevated; silo operating conditions; and classification of a wide range of stored solids according to various features of their mechanical behaviour (abrasive or polishing potential, probability of segregation etc.). Very large silos (~10000 tonnes) used in the cement manufacturing industry have an internal inverted cone in the bottom for functional reasons. A significant number of these large silos have suffered severe damage or collapse, and this form of structure was consequently specifically excluded when EN was drafted (clause (3)). However, a history of structural failures is surely a reason why this item should be covered by the standard, rather than excluded. It is important that rules to cover this widely used arrangement are developed and drafted into the standard. This task is one that has been waiting to be addressed since at least 1983 when the first (completely inadequate) design rules were put forward. It requires two simple theories to be devised and verified: one for symmetrical discharge, the other for local cyclic discharge through outlets in the internal inverted cone. The mechanics basis for Rational basis for the reliability assessment of silo loading combinations for different applications in EN This will be the first regulation of the required design pressures for cylindrical silos with an internal inverted cone. Such silos are currently being constructed all over the world (e.g. China, India, Egypt), often to Eurocode rules. The inclusion of such rules would reinforce the perception that European standards have a leading role worldwide. Significant restructuring of the Annex A in EN 1990 for silos and tanks New section required CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes TCEN1990.T1 SC1/WG5 "Silos and tanks" SC1/WG5 "Silos and tanks" Page 29/87

30 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) the symmetrical theory exists, but it needs verification. The development of a suitable local discharge model will require more time. 5 Pressures in rectangular silos with flexible walls 6 Discharge pressures on vertical silo walls subject to highly eccentric flow channels 7 Pressures in unsymmetrical conical hoppers If rectangular silo walls are required to sustain the full force of the pressures exerted on a rigid surface, the walls become very heavily constructed, with deep stiffeners needed to act as big beams, However when the walls are flexible, the pressures in the stored solid are redistributed towards the container corners, leading to much smaller pressures on the walls. The result is that much lighter containers can be constructed if the walls are flexible, which they can be if the pressures are lower. This meretricious circle has not been exploited yet, but the research on which it is based has been available for some years. It should be covered by rules in the standard. As noted above, suitable data for the definition of pressures on the walls of flexible-walled rectangular silos exists. A small range of tests have been used to verify a slightly wider range of computational predictions. It is not proposed to extend the computational or experimental work, but the existing results must be generalised so that they can be applied to a usefully wide range of materials. This requires definition of the stiffnesses of many solids, and a characterisation of the free parameters in terms of known material properties (e.g. lateral pressure ratio, frictional properties, density). Outlets that are eccentric to the centreline of a silo are often necessary for functional reasons, and silos that are completely geometrically axisymmetric sometimes experience eccentric flows. The pressures caused by eccentric flow are very damaging indeed. A new regulation was introduced in EN , which imposes very severe demands on the structure. This revision of the new rule will seek to make this rule more discriminating, so that its severe demands are limited to those cases where they can be shown to be necessary. But that is a challenging task given the current state of scientific knowledge on granular solids flow. The only known mechanics theory for eccentric discharge pressures was implemented into EN (2006). It has now explained many failures, but is too onerous for the general case. This project requires that a sufficiently simple approximate theory to predict flow channel geometries is devised, followed by a simplification of the existing theory of pressures under such regimes. These are two challenging problems to solve, but a first attempt must be made to make the standard more usable for silos that are not subject to the very worst pattern of loading. The new model should reduce the required metal wall thickness by a factor of perhaps 3, and should greatly reduce reinforcement requirements in reinforced concrete. Unsymmetrical circular hoppers are widely used in agricultural applications because of their functional advantages, but they are currently restricted to very small structures because little is known about the pressure regime or the structural behaviour. They are specifically excluded from EN in (7). This project will address this situation and permit a wider use of unsymmetrical hoppers, giving significant functional advantages in bigger silos. Rectangular storage containers pose significant advantages to plant owners where limited footprint space is available (e.g. on offshore platforms, or in congested industrial sites) or where flat-plated structures are cheaper to manufacture than curved sheet shells. This new development will make rectangular containers lighter and more cost effective. Companies storing large quantities of solids in restricted areas will be the beneficiaries. All silo owners who either need to use eccentric outlets or who have reason to fear that the solids in their silos may occasionally flow eccentrically will be the beneficiaries. Such situations sometimes arise suddenly after years of successful service due to segregation, thermal or hygral differentials, impacting sunlight and similar factors The beneficiaries will be the owners of larger silos who must currently use expensive handling systems to achieve concentric flow from a hopper. This is a structural innovation that can greatly reduce materials handling costs. New Section in 5.7 and amendments to 5.1 and 5.2 Modified clause New Section in 6 SC1/WG5 "Silos and tanks" SC1/WG5 "Silos and tanks" SC1/WG5 "Silos and tanks" Page 30/87

31 Detailed Task Specifications - Tasks relating to EN 1991: Actions (SC1) 8 Overpressure factors for silos under mixed flow 9 Tangent modulus of a particulate solid 10 Thermal differentials producing actions in silos of different geometries 11 Eccentric discharge in a symmetrical hopper under eccentric flow in a cylinder EN defines clearly the different patterns of concentric flow that may be expected in a silo. For one of these, mixed flow, the pressure regime during discharging solids is not defined in EN , though it can lead to much higher pressures in one location and lower pressures in others. This case should be properly documented and the design requirements modified for mixed flow design situations. Solids in silos discharge in mass flow, internal flow or mixed flow. The pressures on the walls are very different according to the flow pattern, but this is largely ignored in EN In particular, new theories, correlated with test results, should be used to define the very high local pressures occurring on the walls of mixed flow silos at the transition from flowing to static solid. It is hoped that a first simple rule can be devised for trial in a relatively short time. The stiffness of a particulate solid has a significant impact on the loads incurred by differential temperatures (external atmospheric cooling of the structure shrinking onto a warm solid), on the pressures in flexible-walled rectangular silos, and on the buckling strength of thin metal silos. Recent research has shed much light on the quantification of this tangent modulus, which depends on both the pressure state in the solid and measurable properties of the solid. This property has an impact on thermal loads, loads due to swelling, and the frightening phenomena of silo quaking and honking. The existing database of tests on the stiffness of particulate solids stored in silos must be reviewed with care by persons who have not been involved in its development, and further simple tests are needed on solids that have not been tested. The stiffness is stress-dependent, and not easily predicted using other properties that are commonly measured (e.g. frictional properties, densities etc.). Funding is sought to extend the database and to verify the model proposed for inclusion in the standard. Thermal differentials between stored solids and the containing structure arise due to changes in the weather (the large mass of solids is thermally stable). The current provisions in EN assume that the solid is vertically constrained against movement. This may be a good model for slender structures, but it is very inappropriate for squatter geometries, where the solid can be vertically displaced by external pressure. A new theoretical model is needed and should be introduced into the standard. Huge overpressures are induced in silos when thermal differentials develop between the thermally inert stored solid and the exposed structure. A small amount of funding is sought to permit the devising of a new theory for the consequences of thermal differentials. This theory must accommodate different silo aspect ratios where the phenomena change. It is planned that this model will be simply verified against computational predictions to provide a basis in mechanics. The eccentric discharge flows noted in Item 3 above also have a major impact on the hopper structure beneath the silo. The current standard makes no provision for such pressures, and an appropriate rule must be devised. Damage to the ring supporting the hopper is a common feature of eccentric flows in hoppers. Benefit: More robust and secure designs for mixed flow silos, which are commonly found where the headroom is limited or where the stored solid particles are susceptible to damage by being dropped from a great height (e.g. agglomerated particles, compressed pellets). Design situations in which load combinations involve thermal loads are greatly affected by the stiffness of the stored solid. The values of combination factors in EN 1990 have a much smaller impact on the final design than this stiffness effect, because hard roundish particles and soft long particles have stiffnesses that differ by several orders of magnitude. In addition, the buckling strength enhancement from solids stiffness in metal silos (EN ) can only be exploited if this provision is included in EN Benefits; This project addresses design situations in which thermal differentials are predicted to produce great increases in pressures, indicating that bursting failures are possible. Often the current rules lead to predictions that practical engineers find not credible. This is damaging to the credibility of the whole standard. This provision will ensure that designers take into consideration the effects of eccentric discharge flows on both the hopper structure and the ring from which it is supported. The benefit will be the elimination of another failure mode in these structures. New clauses in New/modified Section 4 and Annex C.10.2 New Section 7 Modified Section 6 SC1/WG5 "Silos and tanks" SC1/WG5 "Silos and tanks" SC1/WG1 "Climatic actions" SC1/WG5 "Silos and tanks" SC1/WG5 "Silos and tanks" Page 31/87

32 Detailed Task Specifications - Tasks relating to EN 1992: Concrete (SC2) A.3 Tasks relating to EN 1992: Concrete (SC2) There are two tasks related to EN 1992 in Phase 2 of the CEN/TC 250 work programme. These are: - SC2.T2 - SC2.T3 Details of this task are provided in the table below. In accordance with CEN/TC 250 Decision 354, SC2 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC2 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC2 and the Project Team. Page 32/87

33 Detailed Task Specifications - Tasks relating to EN 1992: Concrete (SC2) A.3.1 Task SC2.T2: New Items in EN Task Ref: SC2.T2 Task Name: New Items in EN Outline Task Scope: Harmonization, with consequent reduction of NDP s. Updating of some design rules considering the scientific development in the field and integration with consideration of additional typologies of concrete structures currently used in practice. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. Starting documents: Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Fire resistance Improvements are necessary in EN related to the consideration of the resistance of braced and non-braced columns (very typical solution), thermal conductivity of concrete and spalling. Addressing the design for overall structural behaviour in a more general way is necessary, bridging the robustness criteria and the fire structural engineering methods. The concept to analyze the structure at overall level in strict connection with the robustness criteria requires a strict relation with other bodies internal and external to CEN; the recent work of JCSS on the robustness subject and some advanced researches like Coast, together with fire structural engineering methods, will help in defining the scenarios that should be taken into account and the related safety margins. Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes 2 Ease of use through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. EN will be amended by specific rules related to braced and non-braced columns, thermal conductivity of concrete and spalling; additionally a fundamental bridge will be established between structural behaviour under fire and structural robustness. A more consistent, integrated and safe design will be achieved under fire conditions. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) New design rules will be added to EN ; a new chapter addressing and giving rules for the structural overall behaviour of concrete structures exposed to fire will be necessary. Further details on reference documents CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups Page 33/87

34 Detailed Task Specifications - Tasks relating to EN 1992: Concrete (SC2) A.3.2 Task SC2.3: Further new Items in EN , EN , EN Task Ref: SC2.T3 Task Name: Further new Items in EN , EN , EN Outline Task Scope: Starting documents: Harmonization, with consequent reduction of NDP s. Updating of some design rules taking account of scientific development since 2004 in the field of concrete structures, particularly respect to durability; to existing structures and to new materials, with the scope to address the designer to a better fulfillment of sustainability. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. EN , EN , EN and EN , considering available literature from international technical organisations as e. g. fib Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents Interdependencies Related CEN/TC 250 subordinate groups 1 Ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 2 Stainless Steel Reinforcement The use of stainless steel reinforcement, in case of severe environmental conditions, to improve the durability has to be subjected to specific design rules. Aspects to be investigated and codified are the constitutive relationship, the thermal properties with high and low temperatures, the fatigue resistance. 3 Assessment of existing structures A first item is the necessity to clarify the applicability of design models used for new structures to the existing ones and, when necessary, to introduce new models able to describe the behaviour of damaged and undamaged existing structures: it is the case for instance for bond / ductility / resistance degradation by corrosion and related design rules for ULS, or of membrane effects able to increase the structural resistance with respect to the rules today used for new structures. This work item is relatively new, pre-normative codes deal with existing structures only in general terms (fib established a special Activity Group since only few years ago) and the few available normative codes deal with the subject also with a very general approach; on the opposite the work item of this point is the production of (verification) design rules sufficiently detailed to permit the actual verification of safety level, also in relation with the residual life, within the semi probabilistic approach, described in EN Strengthening with FRP Repair and strengthening by use of materials with a polymer matrix reinforced with long glass, carbon or aramide fibres (FRP) is becoming a widespread technique in existing structures. There is then a need to produce design rules based on the available experimental and theoretical studies. FRP presents a very good resistance to corrosion and then in some specific areas their use can be a very suitable solution for the strengthening of damaged structures. The benefit will be appreciated in safe design for ULS, also with extreme temperatures, and in design by avoidance in durability aspects. A careful evaluation of existing structures will be possible, with important issues both on the safety / functionality and on the actual necessity of intervention for upgrading /repair. Consequently a more sustainable approach to the existing structures use will be achieved. The main benefit will be the rationalization of use of FRP in strengthening of existing structures, by means of a comprehensive approach based on the definition of resisting models addressing the evaluation of safety / functionality, durability and robustness of such type of intervention. New implemented chapters on materials will be produced in EN1992, accounting for the relevant mechanical, physical and chemical parameters of stainless steel. New Annex with design / verification models will be introduced in the code and new resisting mechanism will be envisaged to define in a comprehensive approach, the actual structural behaviour. A new Annex that addresses the conceptual design and use of FRP for structural strengthening and a set of rules, both for ULS and SLS, able to give rise to safe and economical design for strengthening. CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Work with ECISS TC104 WG2 Page 34/87

35 Detailed Task Specifications - Tasks relating to EN 1992: Concrete (SC2) 5 Fibre Reinforced Concrete Addition of fibres to enhance the mechanical properties of concrete and spalling behaviour when exposed to fire is today a common practice, there is then the necessity to introduce in EN 1992 relevant design rules, consideration taken to all the fields in which fibres can be usefully added to concrete: improvement of SLS, ULS resistance, fire resistance with limitation of spalling. A beneficial technique, the use of fibres, for the structural performance will be finally considered in a rational frame by means of design / verification rules for all relevant limit states. The use of fibres will improve the structural performance in a very sustainable approach. The relevant parts of EN 1992 will include new rules for the verification / design of concrete structures containing metallic fibres with respect to the relevant limit states in the main text and a new Annex. Robustness will be also considered. Page 35/87

36 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) A.4 Tasks relating to EN 1993: Steel (SC3) There are four tasks related to EN 1993 in Phase 2 of the CEN/TC 250 work programme. These are: - SC3.T3 - SC3.T4 - SC3.T5 - SC3.T6 Details of these tasks are provided in the tables below. In accordance with CEN/TC 250 Decision 354, SC3 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC3 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC3 and the Project Team. Page 36/87

37 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) A.4.1 Task SC3.T3: Cold-formed members and sheeting - Revised EN Task Ref: SC3.T3 Task Name: Cold-formed members and sheeting - Revised EN Outline Task Scope: Based on an evaluation of all available NAs, the task aims at reducing the number of NDPs and NCCI. Harmonization of member buckling rules with EN and EN Enhanced design rules cold-formed members and sheeting with regard to bearing design and stabilization issues. Strengthening of robustness and serviceability items for cold-formed members and sheeting and their connections. Harmonization and simplification of design rules for connections in accordance with EN In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. Starting documents: EN and its available background documents, existing national codes such as DIN Available technical publications, experimental and theoretical research reports e.g. by ECCS TC7 Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. Support to this task will be given by SC3/SC11 in identifying NDPs where there is a chance for elimination or simplification. SC3/SC11 will also support achieving a consensus with different national views. 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Harmonization of member buckling rules 4 Continuity connection of sheeting at intermediate supports 5 Bearing design of the sheeting and cold formed sections 6 Sheeting under local concentrated and patch loading EN covers cold-formed mainly thin-walled members that buckle locally as well as globally. Verification rules differ slightly from global member buckling according to EN and local buckling according to effective width method in EN Modifications and changes are planned be coordinated with PTs of SC3.T1 and SC3.T4 in order to achieve an utmost harmonization where possible and clarify where differences are needed. The continuity of sheeting by overlapping and sleeve connections is not covered by the EN although this very advantageous device is required by building industry. Improvement of bearing design for: - sheeting supported by cold-formed section with one web (i.e. commonly used Z, C and Sigma purlins) and - cold-formed sections under local transverse forces Harmonisation of interaction rules under combined bending, axial compression and shear force close to bearing. Especially for sheeting. Sheeting under local patch loading, generated by photovoltaic systems. Eurocode 3 Part 1-3 does not cover these new applications in cladding and roof resulting from the demands made by sustainable development. Harmonization of these 3 codes dealing with different but similar buckling phenomena will decisively ease the use for the application in practice. Improvement of general bearing design of cold formed members and sheeting Improved design rules at bearing situations. Harmonised interaction rules at bearings. This is the green and ecologic aspects of the essential requirement of the RPC that should be added in Eurocode (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Modified rules in EN Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups First results of modifications in SC3.T1 Related to SC3.T1 and SC3.T4 SC3/WG3 Modified rules in EN None required in advance SC3/WG3 Modified rules in EN Related with SC3.T4 SC3/WG3 New rules in EN Related with SC3.T4 SC3/WG3 Page 37/87

38 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task 7 Walkability of sheeting The evaluation of walkability of sheeting is necessary to ensure the safety during construction stage. The EN does not treat this aspect. The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task 8 Stabilization with sandwich panels and sheeting 9 Resistance of screws and bolts loaded in shear The sandwich panels and sheeting are often used as stabilization elements. EN will be enlarged in order to take this effect into account for: - sandwich panels and - sheeting used as diaphragm and related issues e.g. the introduction of concentrated loads. The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task Harmonisation and enlargement of design rules for bolts loaded in shear. Improving the overall robustness and serviceability conditions Enlargement of design rules Harmonisation with product standards Harmonisation of design rules with EN Enlargement of rules 10 Review of Annex D Modified buckling curve for out stand elements Improvement of buckling analysis for out stand elements and thin-walled sections including out stand elements. New rules in EN None required in advance SC3/WG3 New rules in EN None required in advance SC3/WG3 Is related to SC3.T1 New rules in EN Related with SC3.T2 SC3/WG3 Modified Annex D None required in advance SC3/WG3 Page 38/87

39 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) A.4.2 Task SC3.T4: Stability of Plated Structural Elements - Revised EN Task Ref: SC3.T4 Task Name: Stability of Plated Structural Elements - Revised EN Outline Task Scope: Starting documents: EN contains the basic requirements for the stability for slender plated elements, frequently used in large spanned building structures, bridges, large crane runway girders or similar. It is therefore important for the harmonization within EN 1993 to develop this part in an early stage compared to the application parts of EN As EN is related to many other basic parts of Eurocode 3 such as EN , EN , EN , EN a harmonization of the various stability design rules is intended in order to minimize ambiguities and to simplify the design by improved clarification. A harmonization of design rules is also foreseen regarding the execution of slender plated elements with regard to imperfections that are covered in EN This tasks also aims at integrating recent results of international studies from RFCS projects in particular regarding extended girder applications such as tapered girder, hybrid girders etc. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. EN and its available background documents and National Annexes. Research reports such as RFCS research project COMBRI+: Valorisation of Knowledge for Competitive Steel and Composite Bridges, Final Report. Several working documents from ECCS-TWG 8.3 Scientific papers published in journals like Journal of Constructional Steel Research. Subtask Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. Support to this task will be given by SC3/WG5 in identifying NDPs where there is a chance for elimination or simplification. SC3/WG5 will also support achieving a consensus with different national views. 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Harmonisation of design rules for flat plate elements with other stability rules in EN Aligning rules for combining local and global buckling of thin-walled members in coupled instabilities (EN member buckling/ EN plate buckling) - Improving consistency of structural plate buckling rules of thin-walled products according EN and plated structural elements according to EN Development of recommendations for shape and amplitude structural plate buckling imperfections EN in view of real structures and tolerances according EN EN is dealing with thin-walled products of typically ,0mm in the area of sheeting, roofing and claddings. EN is dealing with slender flat plate products with thickness larger than 3mm and in plane loading. Both parts EN and EN are dealing with plate buckling issues. The development of consistent rules will harmonize the use of both parts in a significant manner. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) New and modified rules in EN Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Interdependencies Is dependent on first results of SC3.T1 Is related to SC3.T3 Related CEN/TC 250 subordinate groups SC3/WG5 4 Improved interaction rules for plates 5 Improved patch loading rules for plates - Improvement of interaction rules for shear and bending for unstiffened/stiffened plates. - Improvement of interaction for biaxial bending and biaxial compression. - Existing rules are incomplete. There is a demand to improve the existing patch loading rules including interaction for improved design of launching of bridges and of crane runway beams The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. Incorporation of results of international recent studies, from RFCS projects in particular. A better use of natural resources through a more efficient use of material by improved design rules and lower costs of the structures in providing improved design rules. Incorporation of results of international recent studies, from RFCS projects in particular. A better use of natural resources through a more efficient use of material by improved design rules and lower costs of the structures in providing improved design rules. New and modified rules in EN New and modified rules in EN Is dependent on first results of SC3.T1 Is dependent on first results of SC3.T10 and SC3.T5 will profit from SC3/WG5 SC3/WG5 Page 39/87

40 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) 6 Stiffener design - Existing rules are incomplete and partially over-conservative. Improvement of rules for the design of stiffeners 7 Harmonization of design rules for stiffened plated elements - Harmonization between plate buckling rules for normal and thin walled components. - Harmonization of EN with EN especially when transverse loads are applied to stiffened plates e.g. deck plates. It is not demanded to develop new rules for EN , but this belongs to SC3.TC5. However possible clarification and requirements demanded by SC10 or Project Team responsible for EN (SC3.TC5) should be considered for harmonisation and integration where possible. Incorporation of results of international recent studies, from RFCS projects in particular.a better use of natural resources through a more efficient use of material by improved design rules and lower costs of the structures in providing improved design rules. This will ensure a consistency within the whole design process of stiffened flat plated elements as covered for different type of loading and plate thickness in the relevant parts of EN 1993, namely EN , EN and EN New and modified rules in EN New and modified rules in EN None required in advance SC3.T10 is dependent on None required in advance SC3.T5 is related on SC3/WG5 SC3/WG5 The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. 8 Guidance for use of FEM in design - Development of guidance for use of FEM in design - Consistency of rules given in EN and EN with respect to imperfections and FEM. The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. Complex structures are more frequently designed using the Finite Element Method (FEM). The development of design guidance for the use of FEM will thereby follow future design trends and will allow for a harmonized procedure FEM design that is important to guarantee a uniform safety level. New and modified rules in EN Annex C Is dependent on first results of SC3.T1 Is related to SC3.T5 SC3.T.10 and SC3.T5 will profit from SC3/WG5 9 Development of advanced design rules for extended girder applications Girders with plated web elements are often used in different design configuration in order to allow an economical use of material and resources. For the following different type of girders additional and advanced design rules will be developed: - Girders with corrugated webs. This kind of girders are more and more used in daily design work because of their efficient load bearing behaviour. The existing design rules do not cover well all the specifics of this type of girders. - Girders with tapered webs. Existing design rules in EN are based on typical rectangular web. - Hybrid girders: With increasing use of high strength steel the need for efficient and correct rules for hybrid girders with flanges of high strength steels and webs of mild steels becomes relevant. - Girder with plates which are curved in elevation and in plan. There is a clear gap between member sections as used e.g. for bridges and the application of EN for shells. - Girders with web openings. Girders with web openings are increasingly used to account for installation requirements e.g. in buildings. Rules for girders with web openings will be developed by SC4.T2: Composite beams with large web openings The Project team of SC3.T4 should review. harmonize and clarify these with EN where possible for integration into a new part EN Incorporation of results of international recent studies, from RFCS projects in particular. A better use of natural resources through a more efficient use of material by improved design rules and lower costs of the structures in providing improved design rules. New and modified rules in EN None required in advance Is related to SC3.T1, SC3.T5 and SC3.T8 SC3.T10 are dependent on SC3/WG5 Page 40/87

41 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) A.4.3 Task SC3.T5: Harmonisation and Extension of Rules for Shells and Similar Structures - Revised EN and EN Task Ref: SC3.T5 Task Name: Harmonisation and Extension of Rules for Shells and Similar Structures - Revised EN and EN Outline Task Scope: Based on an evaluation of all available NAs, the task aims at reducing the number of NDPs and NCCI. Harmonization of the existing rules for tubulars and shells under global bending from EN across EN , EN , EN , EN , EN and EN Re-drafting of EN to address problems of assemblies of plate elements under transverse loads. Transformation of EN from a limited standard dealing only with plates with simple edge conditions under simple transverse loads into a standard on box assemblies of plates under potentially complex transverse loads with interactions between the plate elements and exploitation of the strength of edges and corners. Extension of the rules to address several aspects that are currently outside the scope of EN , EN , EN and EN Harmonization of rules by eliminating the current serious discontinuities and inconsistencies. Extension of rules for imperfections to be used in for modern computational modelling of complex shell structures. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. Starting documents: EN and EN and its available background documents. Scientific papers published in journals. ECCS P125 European Recommendations on Shell Buckling (2008). Documents of ECCS Technical Group TWG 8.4 Subtask Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Cylindrical shells and tubular members under global bending 4 Shell buckling and boundary condition requirements The current buckling rules of EN for shells and those of EN on tubular members are mismatched by roughly 50% for the critical range that is relevant to chimneys, wind turbine towers, masts, piles, thin tubes, pipelines, storage containers and similar structures. The mismatch is causing some problems for existing applications and inhibits innovation in others. The mismatch arises because shells buckle under local stress states, but tubes respond to global stress resultants, leading to different conceptual models being used historically and leading to mismatches where they meet. This project will resolve these discrepancies and give a harmonized strength description relevant to all tubulars and cylindrical shells under global bending. In all shell structures (aerospace vehicles, nuclear containments, storage containers, towers, chimneys and piles) the buckling strength assessment is based on assumed idealized boundary conditions for each shell segment. For each load case, the effect of the boundaries is different, but a small change can easily reduce the strength by 50%. However, the structural requirements of rings and junctions to realize these conditions in practice are nowhere defined in the standards, leading to uncertainty and overdesign by designers and insecurity for owners. This project will identify and quantify the stiffness Each application (e.g. chimneys) has a history of producing its own rules to predict buckling strength. This leads to difficulties when an innovative structure is not in any of the categories, and the assessed strength appears to depend on how the structure is categorized. A wide range of different types of structure and industries will benefit from this project. It must include an assessment of realistic imperfections in each structural form, since imperfections play a huge role here. All applications of thin shell structures, from tanks and silos to masts, wind turbine towers and chimneys will benefit from a scientific definition of the stiffness requirements at boundaries to produce the defined shell buckling strengths given by the simple assumptions of idealised boundary conditions. Modified and revised section to enlarge the LBA-MNA method in EN Enhanced and clarified Section 2.3 in EN CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Is dependent on first results of SC3.T1 SC3.T12 will profit from this SC3.T12 is dependent on its completion SC3/WG6 SC3/WG7 SC3/WG6 SC3/WG7 Page 41/87

42 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) 5 Buckling of spherical and similar thin shells 6 Imperfections and computational modeling of shells 7 Transformation of EN to deal with box-like assemblies of plates requirements for rings and edge details for the many different buckling modes that can arise. Such a project has never been undertaken before. Spherical domes provide extremely efficient roof structures for large diameter storages, but were omitted in EN The rules of ECCS P125 will be used as a starting point, but they are incomplete: they use an inconsistent approximate calculation process and do not mention the effect of an edge ring, so they must be modified for inclusion in EN It is well known that the buckling of shells is more sensitive to imperfections than any other structural form (over 80% of the potential strength being lost through relatively minor dents). EN reflects this intense concern, with severe imperfections imposed for all computational modelling. More recent research has shown that this issue matters far more for the simple symmetrical conditions that have been extensively studied, but is less important for realistic load cases that have not been experimentally explored. But these practical cases are the ones that need computational modelling. This project will systematically explore the reducing role of imperfections and the increasing role of changes in geometry under unsymmetrical loads. It will devise simpler rules for the assumptions to be made by computational modellers. The published EN only addresses the strength of an individual plate under very simple transverse loadings with trivialized edge conditions. Real containment box structures (especially tanks, silos, reactor vessels and lock gates) have more complex loading, they involve interactions between adjacent plates including both flexure and membrane actions, and they derive considerable strength from the joints and corners between elements. This standard needs a major overhaul to address realistic problems in plate assemblies with transverse loading and membrane stresses in orthogonal directions. The revised standard will be a companion document on flat plate assemblies to EN on curved plates forming shells, so similar provisions will be drafted. All applications in which a thin dome roof provides an economic and efficient structural system. All innovative designs in which the old empirical rules are being superseded by computational modelling to provide more economic and reliable designs. Design provisions for this range of practical structures which are not addressed by any other standard. Coupling with computational modelling to permit much lighter designs than those currently produced using only beam theory. New and revised Annex D.5 in EN Simplification and modification of Section 3.3, 8.4 and 8.7 in EN EN : Radical revision of the standard to extend it and simplify its provisions by replacing extensive tables with simple analytical expressions None requested in advance Is related to SC3.T4 SC3.T12 is dependent on its completion SC3/WG6 SC3/WG7 SC3/WG6 SC3/WG7 SC3/WG6 SC3/WG7 Page 42/87

43 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) A.4.4 Task SC3.T6: Fire design of Steel Structures - Revised EN Task Ref: SC3.T6 Task Name: Fire design of Steel Structures - Revised EN Outline Task Scope: Starting documents: Based on an evaluation of all available NAs, the task aims at reducing the number of NDP and NCCI. Harmonisation of stability rules between fire design according to EN and cold design according to EN General simplification of design rules. Improvement of design rules taking into account modern calculation methods, e.g. by providing additional material parameters. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. Extension of design rules taking into account modern steel grades as e.g. high strength steel and stainless steel. EN and its available background documents. Scientific papers published in journals. Literature and research documents produced by members of Research Committee ECCS-TC3 Fire design" and recent results of RFCS-research. Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. Support to this task will be given by SC3/WG2 in identifying NDPs where there is a chance for elimination or simplification. SC3/WG2 will also support achieving a consensus with different national views 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Material properties for cooling phase of real fires Generally needed to calculate steel structures in real fires, up to now no definition of cooling phase provided. Extension of the scope of EN (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Additional and modified rules in EN Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups None required in advance SC3/WG2 4 Aspects of stability verification - Detailed information concerning structural and geometrical imperfections for advanced calculation methods. - Additional rules for the buckling length of unbraced frames. - Improved and thereby simplified solutions for the classification of cross-sections based on new results of ongoing research project - Improvement of existing buckling curves for LTB depending on type of loading, consistency with Part Joints Improvement of Annex D leads to a more realistic and more general design, introduction of improved design rules for welds and bolts. Evaluation of the application of the component method in practice via survey. 6 Cellular beams According to the decision of SC 3 a new part for the design of cellular beams (EN ) will be developed. Clauses with reference to the new part have to be specified in EN Additional rules dealing with fire design of cellular beams should be included in EN Specification of detailed rules, Incorporation of results of recent international studies Addition of detailed rules Extension of the design rules in EN Additional and modified rules in EN Additional and modified rules in EN , Annex D Additional and modified rules in EN First results of SC3.T1 Is related to SC3.T4 and TCEN1990.T1 Is related to SC3.T2 Is related to SC3.T1 and SC3.T4 and SC4.T1 SC3/WG2 SC3/WG2 SC3/WG2 Page 43/87

44 Detailed Task Specifications - Tasks relating to EN 1993: Steel (SC3) preferably or if necessary in this new part EN The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. 7 Stainless steel The σ-ε-relationship of stainless steels differs significantly from carbon steel. Introduction of new regulations for the fire design of stainless steels. Harmonization with EN The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. 8 High strength steel Introduction of rules for fire design of EN into EN Extension of the design rules in EN Extension of the design rules in EN Additional and modified rules in EN Additional and modified rules in EN Is related to SC3.T7 Is related to SC3.T1 and SC3.T13 SC3/WG2 SC3/WG2 9 Design rules for class 4 crosssections 10 Temperature-dependent ductility of structural steel Improvement of design rules for class 4 cross sections based on recent research work. The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. Currently, fixed value εt,θ =0.15 limiting strain for yield strain, leads to problems in numeric models, experimental results available identifying temperature-dependency of ductility. The fundamental work of this subtask will be undertaken by others. The Project Team will need to review and incorporate this material into their deliverables, adapting it when necessary to ensure that it is consistent with the rest of the work under this task. Extension of the design rules in EN Specification of detailed rules. More effective design method. Specification of detailed rules Additional and modified rules in EN Additional and modified rules in EN Is related to SC3.T1 and SC3.T4 None required in advance SC3/WG2 SC3/WG2 Page 44/87

45 Detailed Task Specifications - Tasks relating to EN 1994: Composite (SC4) A.5 Tasks relating to EN 1994: Composite (SC4) There is one tasks related to EN 1994 in Phase 2 of the CEN/TC 250 work programme. This is: - SC4.T5 Details of these tasks are provided in the tables below. In accordance with CEN/TC 250 Decision 354, SC4 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC4 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC4 and the Project Team. Page 45/87

46 Detailed Task Specifications - Tasks relating to EN 1994: Composite (SC4) A.5.1 Task SC4.T1: Development of rules covering shallow floor construction, and other flooring types using precast concrete elements Task Ref: SC4.T5 Task Name: Development of rules covering shallow floor construction, and other flooring types using precast concrete elements. Outline Task Scope: Starting documents: Establish rules, based on principles contained in EN1994 and EN1993, for the design of shallow floors and other beams using precast units. This specific guidance will greatly ease the use of EN1994, rather than individuals having to compile rules from first principles often with different results. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. EN and EN Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. Support to this task will be given by SC3/WG2 in identifying NDPs where there is a chance for elimination or simplification. SC3/WG2 will also support achieving a consensus with different national views 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Development of design solutions for shallow floor construction 4 Development of design solutions for composite beams incorporating precast concrete units Although shallow floor solutions have seen widespread adoption across Europe for over ten years, they nevertheless postdate the development of current EN1994 content and so are a significant omission from the current scope. Designers would welcome generic guidance to complement the current proprietary guidance that is available for numerous systems. Precast concrete units are often used compositely with steel beams, but (although industry best practice guidance has been available for some time) are not currently covered by the scope of EN1994. Guidance is needed in particular to clarify how to detail the shear connection to ensure safe force transfer. Extend scope of EN1994 to cover current construction practice. Facilitate the uptake of good solutions through the provision of generic guidance. Extend scope of EN1994 to cover current construction practice precast units represent a significant proportion of the flooring market used with composite beams. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Depending on how comprehensive the guidance is, it could appear either as a standalone Part, or as new clauses in EN and EN Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Interdependencies SC3 makes no mention of shallow floors but there will be some interdependency with SC3 Task 1. SC2 Task 1 is very broad but there may be some interdependency SC3 and SC2 see above Related CEN/TC 250 subordinate groups 5 Compilation of solutions into codified rules Present the results of sub-tasks 1 and 2 in the correct format. As above. SC3 and SC2 see above 6 Production of background documentation Production of complementary information to facilitate correct use of new procedures. As above. SC3 and SC2 see above Page 46/87

47 Detailed Task Specifications - Tasks relating to EN 1995: Timber (SC5) A.6 Tasks relating to EN 1995: Timber (SC5) There is one task related to EN 1995 in Phase 2 of the CEN/TC 250 work programme. This is: - SC5.T3 Details of these tasks are provided in the tables below. In accordance with CEN/TC 250 Decision 354, SC5 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC5 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC5 and the Project Team. Page 47/87

48 Detailed Task Specifications - Tasks relating to EN 1995: Timber (SC5) A.6.1 Task SC5.T3: Revised Eurocode 5, part 1-1 Task Ref: SC5.T3 Task Name: Revised Eurocode 5, part 1-1 Outline Task Scope: Starting documents: Harmonisation, reduced number of NDP s, effective material usage (positive effect on climate change) and safety. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. EN ; EN ; National Annexes, including NCCI herein; scientific background from e.g. CIB W18 (in which recent results of international studies are discussed). Subtask Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Design rules with non-continuous (ie stepped) output Replace these design rules by continuous output. (1) Stability of members (2) Compression perpendicular Lateral torsional buckling of (slender) beams is an important issue in light weight structures (like timber structures). The rules must be unambiguous. This applies, of course, for all design rules. However, these noncontinuous results apply also to compression to the grain which affects the design of almost every structure. 4 Holes in beams Structures have to accommodate installation work for which often holes in beams (and columns) are necessary. So far, no corresponding design rules are given in Eurocode 5. These are necessary due to potential brittle failure of such elements in tension perpendicular to the grain. 5 Design rules for foundation piles In certain areas of Europe (and outside Europe as well) wooden foundation piles are more or less extensively used. For example, in the Netherlands and Flanders the market for wooden foundation piles is approximately annually. Design rules are missing in Eurocode 5 and Eurocode 7. 6 Racking resistance of walls Reduction of NDP s. In the present Eurocode 5 two design methods are described which are subjected to a national choice. Only one method is more desirable. 7 Vibrations caused by pedestrians and Floor vibrations In the present Eurocode 5, part 2, a simplified method for simply supported beams or truss systems is given in an informative annex with a reference to future versions of EN More adequate design rules, reflecting the state of the art, are needed in Eurocode 5. Reduction of NDP s. Furthermore, the design rules in the present Eurocode 5 are only meant for residential buildings with rectangular floors. Design rules for other applications and lay outs Robust design rules Harmonisation. Warranted safety. Incorporation of existing national rules which have been reliably applied for many years, taking into account recent results of international studies. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Modified clauses New clauses Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Harmonisation New clauses SC7 Harmonisation Modified clauses SC8 Harmonisation New and modified clauses - Interdependencies Related CEN/TC 250 subordinate groups SC5.T1 (reinforcement) SC5.T5 (connections) Page 48/87

49 Detailed Task Specifications - Tasks relating to EN 1995: Timber (SC5) are missing. 8 Basis of design and material properties In the present Eurocode 5, part 1-1, section 2 and section 3 include Basis of design as well as Material properties. With regard to state-of-the-art (e.g. new materials), simplification and revision of EN 1990, a revision of these parts is needed. Simplification and harmonisation Modified and revised clauses SC 10 Page 49/87

50 Detailed Task Specifications - Tasks relating to EN 1996: Masonry (SC6) A.7 Tasks relating to EN 1996: Masonry (SC6) There is one task related to EN 1996 in Phase 1 of the CEN/TC 250 work programme. This is: - SC6.T4 Details of this task are provided in the table below. In accordance with CEN/TC 250 Decision 354, SC6 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC6 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC6 and the Project Team. Page 50/87

51 Detailed Task Specifications - Tasks relating to EN 1996: Masonry (SC6) A.7.1 Task SC6.T1: Revised version of EN Task Ref: SC6.T4 Task Name: Revised version of EN Outline Task Scope: Reduction of NDP s. Incorporation of fundamental changes in EN that forms the basis of EN , inclusion of new rules to cope with new structural challenges due to increased thermal performance of masonry buildings (wider cavities, more complex floor wall connections, partly supported floor slabs, inclusion of nonmasonry materials within a wall), extension of set of simplified rules Starting documents: EN evolution work, EN Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. In particular, a large effort has to be made for simplifying the calculation of the compressive strength based on the so called normalized strength of masonry units. The reduction of NDP s realized for part -1-1 should be taken over on a 1:1: basis 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Robustness In response to revision of robustness rules in EN 1990 and EN , specific masonry related rules have to be worked out, probably related to consequence classes. Although this subject will be primarily dealt with in part -1-1, a simplified approach may be added to this part. 4 Ultimate limit state Fitting simplified rules with the same theoretical basis as will be made available in part -1-1 (e.g. confined and reinforced masonry, combined loading), should be developed, especially considering currently used innovative products. 5 Provisions for simplified verification of supports of slabs which follow the energy saving standards. (floor slabs supported over part of the thickness of a wall) Until now no verification formulae exist to verify this structural detail which is widely used at solid walls in countries with higher requirements for energy saving. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes SC6.T1 Interdependencies Related CEN/TC 250 subordinate groups Simplified approach to robustness. New clauses SC6.T3 SC6/WG2 "Simplified calculation methods" Simplified rules with respect to the evolution of part -1-1 making the application easy for common structures. New and revised clauses SC6.T1 SC6/WG2 "Simplified calculation methods" Simplified verifications for supports of slabs. New clauses SC6.T1 SC6/WG2 "Simplified calculation methods" Page 51/87

52 Detailed Task Specifications - Tasks relating to EN 1997: Geotechnics (SC7) A.8 Tasks relating to EN 1997: Geotechnics (SC7) There are three tasks related to EN 1997 in Phase 1 of the CEN/TC 250 work programme. These are: - SC7.T3 - SC7.T4 - SC7.T5 Details of these tasks are provided in the tables below. In accordance with CEN/TC 250 Decision 354, SC7 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC7 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC7 and the Project Team. Page 52/87

53 Detailed Task Specifications - Tasks relating to EN 1997: Geotechnics (SC7) A.8.1 Task SC7.T3: Ground Investigation Task Ref: SC7.T3 Task Name: Ground investigation Outline Task Scope: Provide practical guidance for selecting characteristic values of soil and rock parameters. Provide suggested values based on soil and rock description, to be used in the absence of reliable test data. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. Starting documents: Reorganized Eurocode 7 Part 2 (from Task 1) plus new/revised paragraphs from Task 6. Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Selection of characteristic soil and rock parameters from test data 4 Suggested values of characteristic soil and rock parameters Review recent research into this subject and develop better principles and practical rules for the selection of characteristic values in day to day practice. Principles to be based on same reliability theory that underpins the Eurocodes, but to take into account the massive variability of soils and rock parameters. Characteristic values of geotechnical parameter are the most important input in the geotechnical verifications of limit states. So a harmonised selection of these values is the basis of a harmonised geotechnical design. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 11 for Characterisation. Selection of appropriate values for soil and rock parameters is the most important activity undertaken by a geotechnical engineer. In the end, these values make or break the availability of certain design choices. However, the great variability of the materials covered and the limited data available makes this task extremely difficult in day to day practice. Provide suggested values of commonly-used soil and rock parameters based on soil and rock description. Much of this information is published in existing National Annexes and other NCCI documents. Harmonize the values given there to allow greater consistency in design. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 8 for Harmonization. Selection of appropriate values for soil and rock parameters is the most important activity undertaken by a geotechnical engineer. Provision of suggested values makes this task more economic in Increased harmonization Simplification Improved efficiency and transparency in design Simplification Greater user-friendliness Rules for on selecting appropriate characteristic values for a wide range of design situations Increased reliability of design Less variability in outcomes for same design situation Suggested characteristic values for common geotechnical parameters Greater economy of design for simple foundations Less variability in outcomes for same design situation (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Modifications to the text and annexes of EN Modifications to the text and annexes of EN Additions to the text of EN Section 3 New Annex in EN Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups " SC7/WG2 "Ground investigation SC7/WG2 "Ground investigation Page 53/87

54 Detailed Task Specifications - Tasks relating to EN 1997: Geotechnics (SC7) in day to day practice. 5 Alignment with ISO/TC 182/SC 1, CEN/TC 341 and CEN/TC 288 investigation and execution standards 6 Site investigation techniques for seismic and dynamic design 7 Additional site investigation techniques for rock Review existing rules provided in new (separate) ISO/CEN standards on execution and investigation; remove duplication contained within Eurocode 7 by cross-referring outwards. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 2 for Maintenance and ease-of-use. Duplication (and contradiction) of design rules across different standards leads to confusion and errors. Simplification will bring greater clarity and improve the reliability of designs. Provide details of common site investigation techniques used to establish characteristic values of parameters used in seismic and dynamic foundation design. Consider more explicitly the requirements of seismic geotechnical design with regards to site investigation in earthquake-affected regions; supplement the guidance given in EN 1997 Part 2 This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 6 for Seismic design. Proper rules for conducting site investigation to support seismic and dynamic foundation design are lacking or inadequate. Provide details of additional site investigation techniques used to establish characteristic values of rock. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 13 for Rock mechanics Rules for conducting site investigation in rock are currently limited to only basic tests. 8 Practical examples Provide practical examples on how to obtain the characteristics of soil and rock for the end-user, for inclusion in a separate Scientific and Policy Report. Clarity and simplification in the rules that apply to geotechnical design Rules for site investigation for sesimic and dynamic foundation design Revised text in EN Additional text in EN Additional annexes in EN Additional rules for site investigation of rock Additional text in EN Additional annexes in EN SC7/WG2 "Ground investigation SC7/WG2 "Ground investigation SC7/WG2 "Ground investigation Provision of best-practice guidance Scientific and Policy Report SC7/WG2 "Ground investigation Page 54/87

55 Detailed Task Specifications - Tasks relating to EN 1997: Geotechnics (SC7) A.8.2 Task SC7.T4: Foundations, slopes and ground improvement Task Ref: SC7.T4 Task Name: Foundations, slopes, and ground improvement Outline Task Scope: Include widely-used calculation models for geotechnical design based on existing national practice and recent research. Add calculation models for widely used foundations types and techniques, thereby reducing barriers to trade. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. Starting documents: New Eurocode 7 Part 3 (from Task 1) plus new/revised paragraphs from Task 6. Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Spread foundations Add (normative and informative) models for shallow foundations that have been demonstrated to yield good designs. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 10 for Calculation models. Formal surveys of practising engineers have revealed demand for widely-accepted calculation models for spread foundations to be added to Eurocode 7. Engineers need guidance on the best models available for different design situations, without having to resort to non-normative (typically national, not international) documents. 4 Pile foundations Document the most commonly used calculation methods and formulas to determine pile resistance or behaviour for inclusion in (informative) annexes of EN Provide recommended values of any model factors that are needed to ensure consistent levels of reliability. Add to the standard new or more precise rules for common aspects of pile design, such as negative skin friction, lateral loads, pile groups, buckling, dynamic and cyclic loading, etc. These additional rules have to be elaborated. For seismic design of pile foundations a strong relation to EC 8 is planned. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 7 for Pile Design. Formal surveys of practising engineers have revealed demand for widely-accepted calculation models for pile foundations to be added to Eurocode 7. Engineers need guidance on the best models available for different design situations, without having to Increased harmonization of design practice across Europe Improved use of Eurocode 7 in day-to-day design practice Reduced conservatism in design Increased harmonization of design practice across Europe Improved use of Eurocode 7 in day-to-day design practice Reduced conservatism in design Section 2 of new standard EN New annexes in EN Section 3 of new standard EN New annexes in EN CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes SC7.T1 SC7.T1 SC7/WG3 "Geotechnical constructions" SC7/WG3 "Geotechnical constructions" Page 55/87

56 Detailed Task Specifications - Tasks relating to EN 1997: Geotechnics (SC7) resort to non-normative (typically national, not international) documents. 5 Cuttings and embankments Add (normative and informative) models for cuttings and embankments that have been demonstrated to yield good designs. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 10 for Calculation models. Formal surveys of practising engineers have revealed demand for widely-accepted calculation models to be added to Eurocode 7. Engineers need guidance on the best models available for cuttings and embankments for different design situations, without having to resort to non-normative (typically national, not international) documents. 6 Ground improvement Review existing ground improvement techniques and their design to find common principles and rules features for inclusion on Eurocode 7. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 14 for Ground improvement. Techniques for improving in situ ground by deep compaction, soil mixing, and stone or concrete columns are widely used but not covered by the existing version of Eurocode 7. These techniques can offer considerable savings in the total costs of construction. 7 Harmonization of NDPs for pile design 8 Alignment with ENs (structural design of foundations) Review the contents of all countries National Annexes plus available JRC data; collate values for NDPs where they differ from recommended values. Consult with different countries to understand rationale behind NDPs where they are significantly different from recommended values. Perform calculations to demonstrate significance of these variations in NDPs. Reduce the number of NDPs to an acceptable minimum. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 8 for Harmonization and would be performed in conjunction with task SC7.A Pile design varies significantly across Europe and could be made more consistent and economical by the establishment of common rules. Review existing rules given in ENs 1992, 1993, 1995 and 1996 regarding structural design of concrete, steel, timber and masonry foundations. Propose improvements to ensure better alignment with EN 1997 and to reduce unintended conservatism. Foundation construction can be made more economic by establishing better rules for structural design of foundations 9 Practical design examples Provide example calculations to Eurocode 7 for common foundation types. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 3 for Model solutions. Increased harmonization of design practice across Europe Improved use of Eurocode 7 in day-to-day design practice Reduced conservatism in design Provision of rules for design of ground improvement techniques Improved economy in design Increased harmonization of design practice across Europe Alignment with ENs 1992, 1993, 1995 and 1996 Reduced conservatism in design Section 4 of new standard EN New annexes in EN Additions to the text of EN Section 5 of new standard EN SC7.T1 SC7.T1 SC7/WG3 "Geotechnical constructions" SC7/WG3 "Geotechnical constructions" New annexes in EN SC7.T1 SC7/WG3 "Geotechnical constructions" Changes to ENs 1992, 1993, 1995 and 1996 SC7.T1 Tasks belonging to SC2, SC3, SC4, SC5, SC6 SC7/WG3 "Geotechnical constructions" Provision of best-practice guidance Scientific and Policy Report SC7/WG3 "Geotechnical constructions" Page 56/87

57 Detailed Task Specifications - Tasks relating to EN 1997: Geotechnics (SC7) A.8.3 Task SC7.T5: Retaining structures, anchors, and reinforced ground Task Ref: SC7.T5 Task Name: Retaining structures, anchors, and reinforced ground Outline Task Scope: Add precise guidance for common aspects of design of retaining structures; include widely-used calculation models for retaining structures based on existing national practice and recent research. Harmonize partial and correlation factors used by different countries, to reducing barriers to trade. Provide practical examples of best practice to Eurocode 7. In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. Starting documents: New Eurocode 7 Part 3 (from Task 1) plus new/revised paragraphs from Task 6. Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. Increased harmonization Simplification Improved efficiency and transparency in design (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Retaining structures Add (normative and informative) models for retaining structures that have been demonstrated to yield good designs. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 10 for Calculation models. Formal surveys of practising engineers have revealed demand for widely-accepted calculation models for retaining structures to be added to Eurocode 7. Engineers need guidance on the best models available for different design situations, without having to resort to non-normative (typically national, not international) documents. 4 Anchors Extend coverage of anchor design to other than grouted anchors, e.g. to deadman anchors. Add (normative and informative) models for anchors that have been demonstrated to yield good designs. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 1 for Anchors. Formal surveys of practising engineers have revealed demand for widely-accepted calculation models to be added to Eurocode 7. Engineers need guidance on the best models available for different design situations for anchors, without having to resort to non-normative (typically national, not international) documents. Simplification Greater user-friendliness Increased harmonization of design practice across Europe Improved use of Eurocode 7 in day-to-day design practice Reduced conservatism in design Increased harmonization of design practice across Europe Improved use of Eurocode 7 in day-to-day design practice Reduced conservatism in design Section 6in new standard EN New annexes in EN Section 7in new standard EN New annexes in EN CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes SC7.T1 SC7.T1 SC7/WG3 "Geotechnical constructions" SC7/WG3 "Geotechnical constructions" Page 57/87

58 Detailed Task Specifications - Tasks relating to EN 1997: Geotechnics (SC7) 5 Reinforced soil structures Review existing methods of reinforced soil structure design in different countries. Find common features and align them with the Eurocode s limit state-plus-partial factor approach, for inclusion in a new section in EN This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 5 for Reinforced soil. Reinforced slopes offer the possibility of considerable environmental and cost savings during construction, and yet their design is not covered to an adequate degree in the existing version of Eurocode 7. Many countries have been forced to preserve existing non-limit-state national standards, which differ widely in their approach. This leads to inconsistency and confusion in design of mixed structures incorporating reinforced slopes (e.g. highway slopes and abutments), owing to the need to work with more than one design code and (often) philosophy. 6 Alignment with ENs (for structural design) Review existing rules given in ENs 1992, 1993, 1995 and 1996 regarding structural design of concrete, steel, timber and masonry retaining walls. Propose improvements to ensure better alignment with EN 1997 and to reduce unintended conservatism. Retaining wall construction can be made more economic by establishing better rules for structural design of foundations. 7 Practical design examples Provide example calculations to Eurocode 7 for common retaining wall types. This work would make use of the background research being undertaken by TC250/SC7 s Evolution Group 3 for Model solutions. Provision of rules for reinforced slope design Harmonization of practice across Europe Improved clarity of design Alignment with ENs 1992, 1993, 1995 and 1996 Reduced conservatism in design New Section 8in new standard EN New annex on reinforced slope design Changes to ENs 1992, 1993, 1995 and 1996 SC7.T1 SC7.T1 Tasks belonging to SC2, SC3, SC4, SC5, SC6 SC7/WG3 "Geotechnical constructions" SC7/WG3 "Geotechnical constructions" Provision of best-practice guidance Scientific and Policy Report SC7/WG3 "Geotechnical constructions" Page 58/87

59 Detailed Task Specifications - Tasks relating to EN 1998: Earthquake (SC8) A.9 Tasks relating to EN 1998: Earthquake (SC8) There are two tasks related to EN 1998 in Phase 1 of the CEN/TC 250 work programme. These are: - SC8.T2 - SC8.T4 Details of these tasks are provided in the tables below. In accordance with CEN/TC 250 Decision 354, SC8 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC8 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC8 and the Project Team. Page 59/87

60 Detailed Task Specifications - Tasks relating to EN 1998: Earthquake (SC8) A.9.1 Task SC8.T2: Material independent sections of EN Task Ref: SC8.T2 Task Name: Material dependent sections of EN Outline Task Scope: Starting documents: Revision and update of the Material Dependent Sections of EN (Sections 5 to 9). In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structural-element types, all to the extent that is reasonably practical. EN and National Annexes. Information from the JRC database on the Nationally Determined Parameters. ECCS report Assessment of EC8 Provisions for Seismic Design of Steel Structures Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Concrete buildings: Ductility Classes and flat slab systems 4 Steel buildings and composite steelconcrete buildings At present, Section 5 of EN states that the use of ductility class L (low), is recommended only in low seismicity cases. The strength of this recommendation is a bit ambiguous and it has been interpreted in some countries as a prohibition. This entails economic consequences and it is felt that, with some simple additional design rules to enhance the ductility of DCL structures it would be possible to extend its field of applicability to moderate seismicity situations, simplifying the design but still ensuring appropriate seismic reliability. Buildings with flat slabs are currently used in many European countries but EN in its Section 5 states that Concrete buildings with flat slab frames used as primary seismic elements in accordance with are not fully covered by this section. At present, in accordance with EN , these buildings may only be designed for DCL (Ductility Class Low) or the slabs and the supporting columns may be considered as secondary seismic elements. Hence this action aims at the development of design rules for this type of structural systems, namely developing dimensioning and detailing rules for cyclic bending and punching. The European Convention for Constructional Steel Works (ECCS) has prepared a document entitled Assessment of EC8 Provisions for Seismic Design of Steel Structures in which it lists a number of issues regarding Section 6 of EN that, in their view, require clarification or further development. ECCS has also expressed its availability to cooperate with CEN/TC250/SC8 in the activity leading to the revision of Section 6 and also Section 7 of EN The intention of this activity is to evaluate the proposals made by ECCS for such revision and whenever agreed by SC8, to improve and update this Section of EN The main benefit is to improve the rules for the design of structures of different Ductility Classes enabling the extension of applicability of simpler DCL design rules to moderate seismicity cases but still ensuring appropriate seismic reliability. An additional benefit shall be the elimination of the present situation regarding flat slab systems that is detrimental for the practical use of EN The present situation corresponds to a void in the scope of Section 5 that creates ambiguity in its application to a widely used typology of reinforced concrete buildings. The main benefit is to bring Sections 6 and 7 up to date with the more recent advances in seismic design of steel buildings, discussing and incorporating the proposals of the leading European Association in the field of steel structures. Improvement of the consistency between the Steel and Composite sections of EN and EN and EN shall also be achieved Updating of Section 5 (Specific Rules for Concrete Buildings) revising the design rules for the three current Ductility Classes, in view of simplifying the design process throughout a wide seismicity range. Updating of this Section shall also incorporate new rules for buildings with flat slab systems, removing the present limitation in its scope. Inclusion of analysis, dimensioning and detailing rules for the design of columnslab connections. Updating of Section 6 (Specific Rules for Steel Buildings) and Section 7 (Specific Rules for Composite Steel-Concrete Buildings) to incorporate the proposals from ECCS. CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes PT1 output PT1 output SC8/WG5 "Concrete" SC8/WG2 "Steel and composite structures" Page 60/87

61 Detailed Task Specifications - Tasks relating to EN 1998: Earthquake (SC8) 5 Timber buildings Section 8 of EN on timber buildings suffered very little change in the conversion process from the ENV stage. Hence, its contents are outdated and needs updating.aspects to be added or updated are:a) General re-evaluation of the building typologies and the values of the behaviour factors;b) Provisions for Capacity Design, including overstrength factors of ductile connections;c) Definition of interstorey drift limits for performance-based design;d) Provisions for wood-based materials such as crosslaminated panels (xlam) and oriented strand boards (OSB), and some fasteners;e) Inclusion of rules for the design of buildings with composite lateral load resisting systems (for instance timber wall panels with concrete cores or steel bracings;f) More detailed rules for the design of shear walls and horizontal diaphragms. 6 Masonry buildings Masonry buildings represent a very large proportion of low rise construction in Europe but the provisions of EN did not achieve an in depth harmonization of design provisions as achieved for other materials. This is evident from the very large number of Nationally Determined Parameters (NDPs) provided for masonry buildings, including the values of the Behaviour Factor (to the contrary of the provisions to other materials). Furthermore there have been some claims that the present rules for simple buildings (mostly presented as NDPs) are disputable and inconsistent with post earthquake field surveys and consequently should be revised. Specifically, the project aims at the extension of the overstrength ratio concept to masonry (as foreseen for other materials, depending on the system redundancy), the improvement of the provisions for the prevention of out of plane collapse of masonry walls and the in depth revision of the rules for simple buildings. 7 Infilled frames and claddings Framed buildings with masonry infills are very common in southern Europe countries. Section 5 of EN already includes design provisions to account for the presence of infills but they are mainly devoted to avoid possible detrimental effects that the infills may cause to the main structure. To the contrary, the beneficial effects (namely being the source of overstrength and energy dissipation) are not yet accounted for. Improvement of the provisions of EN regarding infills could be sought but the implications of fully exploiting masonry infills in the design of new buildings should be carefully evaluated since it entails higher complexity of design and stricter quality assurance requirements for the construction of the infills. Additionally the recent earthquakes, namely in l Aquila (Italy), have shown that in many recent buildings where the structure behaved properly, heavy damage in claddings and cladding panels occurred. This recommends that the design provisions of EN for infilled frames should be extended to cover cladding elements and panels, together with other types of enclosures. 8 Aluminium structures To the contrary of all other structural materials covered by the Eurocodes, EN does not include information regarding Aluminium structures.this creates a void that some countries have solved in their National Annexes but it should be addressed and eliminated altogether in EN The main benefit is to bring Section 8 up to date with the state of the art for the seismic design of timber buildings, incorporating the results of recent research programs.this shall improve the conditions for the use and exploration of the intrinsic favourable characteristics of timber with regard to seismic actions. Improvement of the consistency between the Timber section of EN and EN shall also be achieved. The main benefit of this action is to update and improve the rules for the design of masonry buildings and to reduce the number of Nationally Determined Parameters of Section 9. Furthermore the provisions for simple buildings shall be improved. The main benefit of this action is to improve the rules already presented in EN for infilled frames and also to extend them to claddings and cladding panels. This shall reduce the risk of out of plane collapse of these types of elements. Such collapse may be detrimental to the main structure since it introduces irregularities in its seismic response. Also, such collapses are life-threatening and may cause heavy economical losses. The benefit of this action is to eliminate the current absence of seismic design rules for Aluminium structures. The action shall be developed in liaison with CEN/TC250/SC9 to ensure consistency with the provisions of EN Thorough updating of Section 8 (Specific Rules for Timber Buildings) of EN to incorporate the more recent advances in seismic design of timber buildings.extension of the building typologies and the wood-based materials covered by this Section. Revision of the values of the behavior factors. Improvement of Section 9 (Specific Rules for Masonry buildings) of EN for better consistency with the Sections on other materials and reduction of NDPs (as much as possible accounting for the large variability of masonry units and construction practices prevailing across Europe). The aim of the project is to re-visit this issue in EN and to re-evaluate fully the implications of the presence of infills for the seismic design of buildings. This should be done in conjunction with the revision of Section 9 for Masonry buildings, in view of some common aspects that exist between the two situations. Topics for possible inclusion in the project are the improvement of the modeling and seismic design verifications for infill panels and cladding panels with and without openings (including the evaluation of strength, stiffness and deformation capacity) and the requirements for the connections to the main structure. Inclusion of a new Section in EN for Aluminium buildings or extension of the provisions of Section 6 (Specific rules for Steel buildings) to encompass also Aluminium buildings. PT1 output PT1 output This sub task has to be closely coordinated with sub tasks 3 and 6 (updating of Sections on concrete and masonry buildings). - SC8/WG3 "Timber" SC8/WG1 "Masonry" Page 61/87

62 Detailed Task Specifications - Tasks relating to EN 1998: Earthquake (SC8) A.9.2 Task SC8.T4: Evolution of EN Task Ref: SC8.T4 Task Name: Evolution of EN Outline Task Scope: Starting documents: Revision and update of EN In drafting the new work, care will be taken to be as clear as possible, to use simple routes throughout the document, and to avoid additional and/or empirical rules for particular structure or structuralelement types, all to the extent that is reasonably practical. EN and National Annexes. Information from the JRC database on the Nationally Determined Parameters. Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Soil structure interaction Dynamic soil-structure interaction may influence substantially the seismic response of structures and, accordingly, the consideration of such effects is already required in EN (Foundations, retaining structures and geotechnical aspects) for some specific cases and in all cases in case of pile foundations. However, the provisions therein included are quite generic and there is room to extend and improve them with more practical information to the designer for shallow and deep foundations and for the verification of dynamic base failure. On the other hand there could be cases of pile foundations where soil structure interaction may be disregarded. These cases should be identified for the sake of the ease of use of EN The new provisions should take account of the implication of the development of the pushover analysis. Extension of the practical use of EN to very common cases in foundations of buildings and bridges. Simplification of the design process in cases where soil structure interaction may be disregarded. Improvement of the consistency between EN and Eurocode 7, through proper liaison with CEN/TC250/SC7. Updating of EN for the inclusion of soil structure interaction in the case of shallow and deep foundations, namely the effect of lateral restraint of piles provided by successive soil layers. Inclusion of specific seismic design provisions for modeling, analysis, dimensioning and detailing of piles. General revision of EN with regard to other geotechnical aspects. CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes PT1 output SC8/WG4 "Seismic action and site clasifications" SC7 Page 62/87

63 Detailed Task Specifications - Tasks relating to EN 1999: Aluminium (SC9) A.10 Tasks relating to EN 1999: Aluminium (SC9) There is one task related to EN 1999 in Phase 2 of the CEN/TC 250 work programme. This is: - SC9.T3 Details of these tasks are provided in the tables below. In accordance with CEN/TC 250 Decision 354, SC9 will be responsible for the technical work of Project Teams created in response to Mandate M/515 relating to EN Responsibilities for technical review and preparing contributions to the Project Team may be delegated by SC9 to subordinate Working Groups and Tasks Groups, in particular those listed in the table below. In order to address interdependencies with other tasks and activities of CEN/TC 250, there may be a need to prioritise aspects of the Project Teams work. Requirements to prioritise the Project Team work will be agreed between SC9 and the Project Team. Page 63/87

64 Detailed Task Specifications - Tasks relating to EN 1999: Aluminium (SC9) A.10.1 Task SC9.T3: Long span Structures Task Ref: SC9.T3 Task Name: Long Span Structures Outline Task Scope: New provisions on both roofing and bridging. They have the scope to give particular rules for the design of roofing systems, by extending the general structural provision of Part 1.1 to the specific structural schemes and details typical for roofing. Starting documents: 1. Two Twin Aluminum Domes of the Enel Plant in Civitavecchia (Italy), F. M. Mazzolani, 11th INALCO Conference 2010, Eindhoven, June Domes in the Enel plant, F. M. Mazzolani, HERON 55 No.3/4, Aluminum Structures in Restoration Project of the Mercati Traianei in Rome, F. M. Mazzolani, 5th int. Congress Restoration of Architectural Heritage, Firenze, September Canadian Standard Association, Design of Aluminium Bridges, The use of aluminium in the restoration of the "Real Ferdinando" bridge on the Garigliano river, Festschrift Ehren Von Prof. Dr. Ing. Günther Valtinat Herausgegeben von Jürgen Priebe und Ulrike Eberwien, Druck: General Anzeiger, Rhauderfehn Use of Aluminium Alloys in Retrofitting Ancient Suspension Bridges, F. M. Mazzolani and E. Mele, Int. Conf. on Composite Construction Innsbruck September 1997, Sub-task Ref. Sub-task name Brief description, background and reasons for the work Key benefits Output 1 Reduction in number of National Choices (NDPs) Review the contents of all Countries National Annexes and key supporting documents provided to the Project Team. Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. 2 Enhanced ease of use Apply recommendations in CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes (N1239). Enhance ease of use by improving clarity, simplifying routes through the Eurocode, avoiding or removing rules of little practical use in design and avoiding additional and/or empirical rules for particular structure or structural-element types, all to the extent that it can be technically justified whilst safeguarding the core of essential technical requirements. 3 Design methodologies and structural details for space frames and special roofing systems 4 Design methodologies and structural details for special bridge systems, including rehabilitation of existing bridges The introduction in the market of new structural typologies in the field of large structures for roofing, requires specific design rules, which must be tailored and detailed with regard to the specific material properties and construction technology. This will enable the benefits of using aluminum in such situations, when it can be competitive with other materials, i.e. in situations requiring particularly high corrosion resistance and light weight. The introduction in the market of new structural typologies for bridges, as well as the use of aluminium for rehabilitation of old bridges made of steel and/or reinforced concrete, requires specific design rules, which must be tailored and detailed with regard to the specific material properties and construction technology. This will enable the benefits of using aluminum in such situations when it can be competitive with other materials, i.e. in situations requiring particularly high corrosion resistance and light weight. New aluminium structural system for roofing. New aluminium structural systems for bridging (e.g. new Eurocode part; new or modified clauses in existing Eurocode part) New Annex to EC9 part 1-1. New Annex to EC9 part 1-1. Further details on reference documents CEN/TC 250 Position paper on on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes CEN/TC 250 N1239 "Position paper on enhancing ease of use of the Structural Eurocodes Interdependencies Related CEN/TC 250 subordinate groups Partly dependent on SC9.T1 and T2 Partly dependent on SC9, T1 and T2 Page 64/87

65 Annex B CEN/TC 250 Position paper on enhancing ease of use of the Structural Eurocodes B.1 Purpose of this document (CEN/TC 250 Document Reference N1239) This document presents the overall CEN/TC 250 vision, approach and specific aspects of guidance for enhancing the ease of use of the Structural Eurocodes. Its purpose is to support decision making of CEN/TC 250 Sub-Committees (SCs), Working Groups (WGs) and Project Teams (PTs) engaged in drafting a more user-orientated second generation of Structural Eurocodes. The guidelines presented in this paper are not intended to provide contractual requirements to SCs, WGs and PTs. Given the complexity of the objective and the inevitable tensions that can arise between competing demands, balanced judgements need to be made about the application of the guidelines. Thus, the obligation on SCs, WGs and PTs is that the guidelines should be understood and taken into consideration, informed judgements made and that decisions taken can be justified. This document needs to be read as a whole. B.2 Background Improving the ease of use of the Eurocodes is an important issue discussed at some length by CEN/TC 250 and its subcommittees over recent years. It has also been of significant interest and concern in many CEN member countries. Enhancing the ease of use of the Eurocodes is a priority for CEN/TC 250 and a specific requirement of the European Commission Mandate M/515 issued to CEN in December 2012 [1]. CEN/TC 250 committed to improving the ease of use of the Eurocodes through Resolution 280 made in Helsinki in June 2010 and reproduced below. To assist with this, in November 2013 CEN/TC 250 agreed to create a Chairman s Advisory Panel on ease of use [2] (hereinafter called CAP) to develop recommendations for the approach to be taken to enhance the ease of use of the Eurocodes. The 15 members selected provided a balance between the Eurocodes stakeholders, with an emphasis on practitioners and individuals experienced in the development of the Eurocodes. Detailed information on the thorough and open process followed by the CAP to establish their recommendations on how the ease of use of the Structural Eurocodes can be enhanced is provided in the full CAP report [3]. CEN/TC 250 has considered the CAP recommendations, as well as comments and suggestions from CEN/TC 250 members [4], and has produced the guidelines presented in this paper. Page 65/87

66 RESOLUTION 280 (CEN/TC 250, Helsinki, 18th June 2010) Subject: CEN/TC 250 simplification of Eurocodes CEN/TC 250 acknowledges the challenge established in the Programming Mandate M/466 addressed to CEN in the field of the Structural Eurocodes to examine the potential for simplification of rules in the further development of the Eurocodes. CEN/TC 250 agrees to work towards achieving such simplification in the further development of the Eurocodes to support the ease of their use by designers through: (i) improving the clarity; (ii) simplifying routes through the Eurocodes; (iii) limiting, where possible, the inclusion of alternative application rules; (iv) avoiding or removing rules of little practical use in design; CEN/TC 250 agrees that such simplification should be limited to the extent that it is technically justified and should seek to avoid additional and/or empirical rules for particular structure or structural-element types. The resolution was agreed by unanimity. B.3 Vision: delivering long term confidence At the time of its publication, the first generation of Structural Eurocodes was the most comprehensive and advanced suite of design standards in the world and an outstanding example of harmonisation across countries, structural materials and types of structure. CEN/TC 250 s ambition is to build upon this accomplishment. Whilst respecting the achievements of the past, our vision for the second generation of Structural Eurocodes is to create a more user-orientated suite of design standards that are recognised as the most trusted and preferred in the world. Attaining this vision is a complex challenge. Nevertheless, long-term confidence in the Eurocodes is based on their ability to evolve. Enhancing the ease of use of the Eurocodes is an essential component of the process of evolution. More than practitioners and thousands of other users across Europe and other countries outside Europe will be affected by the evolution of the Eurocodes. CEN/TC 250 is committed to having their needs at the forefront of our minds throughout our work. B.4 Approach: five pillars to enhance ease of use The CEN/TC 250 approach to guide decision making of SCs, WGs and PTs involved in developing the second generation of Eurocodes is based on the five pillars presented in Fig. B1. They provide the overall framework and a transparent approach for enhancing the ease of use of the Eurocodes. These pillars are connected. The statements of intent to meet users needs have been translated into a series of governing principles. The application of these principles will be illustrated through relevant examples. Performance measures can be used, where appropriate, to assure that the intended Page 66/87

67 objectives are being achieved. Finally, central management, governance and support will ensure that a focus on ease of use is sustained, interdependencies are recognised and responded to, and that emergent issues are addressed. The five pillars have been derived from Recommendation 1 of the CAP [3] and the comments and suggestions from CEN/TC 250 members [4]. Guidelines on each pillar are presented in the next section. Figure B1: Five pillars to enhance ease of use of the Eurocodes B.5 Guidelines: realising our ambitions Five guidelines are given below to guide decision making in drafting a more user-orientated second generation of Eurocodes. These guidelines relate to each of the five pillars in Fig 1. B.5.1 Statements of intent to meet users needs The development of the second generation of Structural Eurocodes will be undertaken focussing on users needs. Ten categories of users have been identified. However, whilst all users of the Eurocodes are important, it is not possible to fulfil all their aspirations simultaneously. Therefore, a primary target audience has been identified to focus drafting efforts. The primary target audience will take precedence if conflicts with needs of other audiences arise. The primary target audience for the Eurocodes evolution is Practitioners Competent engineers as defined in Fig. B2. For all categories of users statements of intent setting out the aims of CEN/TC 250 are presented in Fig. B3. Page 67/87

68 PRIMARY TARGET AUDIENCE DEFINITION Practitioners Competent engineers Competent civil, structural and geotechnical engineers, typically qualified professionals able to work independently in relevant fields Figure B2: Primary target audience for the Eurocodes evolution CATEGORIES OF EUROCODES USERS Practitioners Competent engineers [Primary target audience] Practioners Graduates Expert specialists Product Manufacturers Software developers Educators National regulator Private sectors businesses Clients Other CEN/TCs CEN/TC 250 STATEMENTS OF INTENT We will aim to produce Standards that are suitable and clear for all common design cases without demanding disproportionate levels of effort to apply them We will aim to produce Eurocodes that can be used by Graduates where necessary supplemented by suitable guidance documents and textbooks and under the supervision of an experienced practitioner when appropriate We will aim not to restrict innovation by providing freedom to experts to apply their specialist knowledge and expertise Working with other CEN/TCs we will aim to eliminate incompatibilities or ambiguities between the Eurocodes and Product Standards We will aim to provide unambiguous and complete design procedures. Accompanying formulae will be provided for charts and tables where possible We will aim to use consistent underlying technical principles irrespective of the intended use of a structure (e.g. bridge, building, etc.) and that facilitate the linkage between physical behaviour and design rules We will endeavour to produce standards that can be referenced or quoted by National Regulations We will continue to promote technical harmonization across European markets in order to reduce barriers to trade We will produce Eurocodes that enable the design of safe, serviceable, robust and durable structures, aiming to promoting cost effectiveness throughout their whole life cycle, including design, construction and maintenance We will engage proactively to promote effective collaboration with those other CEN/TCs that have shared interests Figure B3: Statements of intent to meet users needs B.5.2 Principles and related priorities Governing principles to guide the drafting of a more user-orientated generation of Eurocodes are given in Table B1. These governing principles have been classified into primary general principles and secondary specific principles. If conflicts arise, primary general principles shall take precedence over secondary specific ones. Within the two classifications, the principles are not ordered. Balanced judgements will therefore need to be exercised if conflicts arise between principles within the primary or secondary classifications. These principles reflect best practice in the development of Standards, Page 68/87

69 satisfy CEN/TC 250 Resolution 280, are consistent with CEN s Internal Regulations and focus on those decisions that are under the control of CEN/TC 250. General principles (primary) Table B1: Principles and related priorities 1 Improving clarity and understandability of technical provisions of the Eurocodes 2 Improving accessibility to technical provisions and ease of navigation between them 3 Improving consistency within and between the Eurocodes 4 Including state-of the-art material the use of which is based on commonly accepted results of research and has been validated through sufficient practical experience 5 Considering the second generation of the Eurocodes as an evolution avoiding fundamental changes to the approach to design and to the structure of the Eurocodes unless adequately justified Specific principles (secondary) 6 Providing clear guidance for all common design cases encountered by typical competent practitioners in the relevant field 7 Omitting or providing only general and basic technical provisions for special cases that will be very rarely encountered by typical competent practitioners in the relevant field 8 Not inhibiting the freedom of experts to work from first principles and providing adequate freedom for innovation 9 Limiting the inclusion of alternative application rules 10 Including simplified methods only where they are of general application, address commonly encountered situations, are technically justified and give more conservative results than the rigorous methods they are intended to simplify 11 Improving consistency with product standards and standards for execution 12 Providing technical provisions that are not excessive sensitive to execution tolerances beyond what can be practically achieved on site The CAP has suggested targets and possible actions for each principle: they are illustrated in the final CAP report [3]. B.5.3 Examples It will be valuable to illustrate the application of the governing principles through relevant examples to promote shared understanding and convergence of approach (e.g. through a better organisation of contents, better harmonisation, etc.). In support of this effort, early in the evolution work, SCs and WGs will identify areas in their standards that present opportunities for enhancing ease of use following the principles in Table 1 and present Page 69/87

70 tentative illustrations of how such improvement can be achieved. These examples will be developed through collaboration between SCs and WGs using the CEN/TC 250 CG as a forum for discussion. Furthermore, under the coordination of WG1 early action will be taken on improving consistency between different Eurocode parts by using common structure and text. B.5.4 Strategic performance measures Understanding and assessing progress in applying the recommendations contained in this paper is important to provide confidence that CEN/TC 250 s ambitions for enhancing the ease of use of the Eurocodes are being achieved. Therefore, strategic performance measures may be used where merited and in collaboration with SCs, WGs and HGs to examine how the governing principles are being applied and to assess CEN/TC 250 s progress towards our objective. Suggestions for possible performance measures are provided in the final CAP report [3]. B.5.5 Management, governance and support The CEN/TC 250 management group will be responsible for monitoring the overall application of the guidelines in this report. It will establish arrangements to assure that the recommendations of this report are implemented appropriately by SCs, WGs and PTs. In support of this, issues of ease of use will be included in the SC/WG report template and agenda for CG meetings to enable good practices and lessons learned to be shared and to promote consistency of implementation of the ease of use recommendations. B.6 References [1] CEN/TC 250 Mandate M/515 EN Mandate for amending existing Eurocodes and extending the scope of Structural Eurocodes, December 2012 [2] CEN/TC 250 Chairman s briefing note 2013/4. Chairman s Advisory Panel on Ease of Use, November 2013 [3] CEN/TC 250 Chairman s Advisory Panel. Final report on enhancing ease of use of the Structural Eurocodes and reducing NDPs, December 2014 [4] CEN/TC 250 Summary of comments on the CAP short report and actions taken, January 2015 Page 70/87

71 Annex C CEN/TC 250 Position paper on reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes C.1 Purpose of this document (CEN/TC 250 Document Reference N1493) This document presents the overall CEN/TC 250 approach and specific aspects of guidance for reducing the number of Nationally Determined Parameters (NDPs) in the Structural Eurocodes. Its purpose is to support decision making of CEN/TC 250 Sub-Committees (SCs), Working Groups (WGs), Horizontal Groups (HGs) and Project Teams (PTs) engaged in drafting the second generation of Structural Eurocodes. Given the complexity and sensitivity of the objective, balanced and respectful judgements need to be made about the application of the guidelines. The obligation on SCs, WGs, HGs and PTs is that the guidelines should be understood and taken into consideration, informed judgements made, and that decisions taken can be justified. C.2 Background Achieving a reduction in the number of NDPs in the Eurocodes is an agreed objective of CEN/TC 250 and a specific requirement of the European Commission Mandate M/515 for the development of the second generation of EN-Eurocodes. For this reason, in the scope of tasks for Project Teams in the Call for Experts for Phase 1 of the CEN/TC 250 work programme, the following was included concerning the reduction of NDPs: Nationally Determined Parameters (NDPs) allow Countries to decide on safety levels, and to give national geographic and climatic data, in National Annexes. The inclusion of NDPs in the published Eurocodes has been more extensive than was originally envisaged. All tasks concerned with existing Eurocode parts include a requirement to work to reduce the number of NDPs and enable better consensus on values adopted by Countries. Guidance will be provided by CEN/TC 250 on the approach to be followed. However, it is expected that the work of Project Teams will be focussed only on a proportion of the existing NDPs, as identified and agreed with the relevant SC, WG or HG. Furthermore in the relevant task definitions, Sub-task no. 1 in all Tasks of Project Teams engaged in the evolution of first generation Eurocode Parts to second generation ones, states: Following guidance provided by CEN/TC 250, agree NDPs to consider for detailed review with the relevant SC/WG/HG. Develop proposals to reduce the number of NDPs and/or Page 71/87

72 enable better consensus on values adopted by Countries to be achieved. Incorporate those proposals agreed with the relevant SC/WG/HG into task deliverables. This paper is intended to provide the guidance referenced in the Call for Experts. The issue of NDPs has been the subject of discussions in CEN/TC 250 and its SCs, WGs and HGs for several years. In support of developing the guidelines contained in this position paper, at its meeting in Dublin in May 2015, CEN/TC 250 agreed to the establishment of an ad hoc group to provide guidance on the definition of legitimate NDPs. CEN/TC 250 has considered the recommendations contained in the final report of this ad hoc group [2], as well as the associated discussions at the CEN/TC 250 meeting in Lisbon in November 2015, and the synthesis of these discussions presented by the CEN/TC 250 Chairman at that meeting [3], and has produced the guidelines presented in this paper. Further background to the number of NDPs in the current generation of Eurocodes and their legal basis is included in Appendix C1. C.3 Objectives and governing principles CEN/TC 250 has three primary objectives associated with the treatment of NDPs during the development of the second generation of the Structural Eurocodes. These are: 1. To reduce the number of National Determined Parameters 2. To develop Standards that can be implemented by CEN members 3. To maintain consensus, evidenced through positive formal votes by CEN members In support of these objectives, CEN/TC 250 has established the following principles to guide efforts to reduce the number of NDPs in the Eurocodes: 1. The development of the second generation of the Eurocodes is an evolution, thus the approach to reviewing NDPs should build from the basis for them set out in Guidance Paper L (see Annex A) 2. Some parameters must be NDPs, even if all countries agree on a specific value or choice 3. Some parameters are subject to variation for geographic or climatic reasons; these must be NDPs although the Eurocodes should be as clear as possible on how they are to be determined 4. Effort should be made to limit the number of other NDPs, but this must be done pragmatically and respectfully of national positions Page 72/87

73 C.4 Approach The approach to reducing the number of NDPs comprises three steps. These are to be undertaken by SCs, WGs and HGs, in conjunction with their relevant PTs. These three steps are directly applicable to the review of current NDPs during the revision of existing Eurocode parts. The guidance underpinning each step is also applicable in the development of new Eurocode parts or where the introduction of a new NDP into an existing Eurocode part is being considered as a result of a change in scope or technical provisions. C.4.1 Step 1: Identification of parameters that must be NDPs In the first step, all parameters that must be NDPs are to be identified. Such essential NDPs are: partial factors for materials and actions, the probability of the design seismic action being exceeded in a structure s design reference period, the time of fire exposure, design accidental actions, classification of structures in Consequences Classes corresponding to different Reliability Classes and levels, taking into account quality management requirements All essential NDPs shall be retained in the Eurocodes, thereby allowing them to be specified in National Annexes. The only exception to this are cases when an NDP was included in the current Eurocodes with a recommended value of 1.0 and there is consensus that it can be removed. This might arise, for example, where all countries have adopted the recommended value of 1.0 and other related NDPs such as general partial factors for materials or actions provide an adequate basis to treat those matters within the competence of European member states. C.4.2 Step 2: Review of other NDPs All NDPs that are not classified as essential in Step 1 shall be reviewed in an effort to try to reduce their number. This review should be undertaken pragmatically, respecting the position of different CEN Members and seeking to understand why different opinions are held. In undertaking this review, NDPs relating to the following are discouraged: technical issues, such as the choice of one mechanical model versus another, or one coefficient versus another in a resistance formulation, limits on geometric or similar parameters (e.g., size of cross section, upper or lower limits on reinforcement ratio or density) which have to do with limits of applicability of mechanical models, choice between advanced and simplified methods. Page 73/87

74 In addition, consideration should be given to eliminating NDPs that concern issues of performance that could be addressed at a project rather than national level. Consideration may also be given to using classes for some families of related NDPs. If such approaches are proposed, examples should be presented at the CEN/TC 250 Coordination Group to promote consistency. C.4.3 Step 3: Reporting Each SC, WG and HG shall report to CEN/TC 250 on the outcome of their efforts to reduce the number of NDPs. This shall be done by preparing a table listing the current NDPs and, as a minimum, identifying those deemed as essential, providing justification for the retention of other NDPs and confirming whether consensus has been reached on NDPs to be removed. This table shall also identify any new NDPs and why they are needed. C.5 References [1] CEN/TC 250 Mandate M/515 EN Mandate for amending existing Eurocodes and extending the scope of Structural Eurocodes, December (CEN/TC 250 document reference N993) [2] CEN/TC 250 Ad Hoc Group on Reduction of NDPs. Guidance for the definition of legitimate Nationally Determined Parameters (NDPs) in Structural Eurocodes, October (CEN/TC 250 document reference N1362) [3] CEN/TC 250 Chairman s notes on the reduction of NDPs. Presentation given at CEN/TC 250 meeting Lisbon as a synthesis of discussions, November (CEN/TC 250 document reference N1403) Page 74/87

75 Appendix C1 Further background to National Determined Parameters C1.1 Number of NDPs in the current generation of Eurocodes Table C1 provides a summary of the number of NDPs in the current EN Eurocodes and their breakdown, relative to the number of Parts in each Eurocode and its total number of pages. Eurocode No of Parts No of Pages No of NDPs EN Annex A EN EN EN EN EN EN EN EN EN Table C1: Analysis of NDPs in current Eurocodes C1.2 Legal basis of NDPs NDPs replaced the boxed values in the ENV-Eurocodes. It is accepted by all those involved in the conversion of ENVs to the first generation of EN Eurocodes that the NDPs were invaluable in that phase as a means to overcome disagreement between CEN Member States on key issues and avoid impasse situations. In that sense, their use was beyond the original intention. The original legal basis of the NDPs and their predecessors (the boxed values in the ENVs) is not wholly clear. However, their incorporation in the EN Eurocodes followed Guidance Paper L (GPL), which stated: The determination of the levels of safety of buildings and civil engineering works and parts thereof, including aspects of durability and economy, is, and remains, within the competence of the Member States Possible difference in geographical or climatic conditions (e.g. wind or snow), or in ways of life, as well as different levels of protection that may prevail at national, regional or local level will be taken into account by providing choices in the EN Eurocodes for identified values, classes, or alternative methods, to be determined at the national level (named Nationally Determined Page 75/87

76 Parameters). Thus allowing the Member States to choose the level of safety, including aspects of durability and economy, applicable to works in their territory When Member States lay down their Nationally Determined Parameters, they should: - choose from the classes included in the EN Eurocodes, or - use the recommended value, or choose a value within the recommended range of values, for a symbol where the EN Eurocodes make a recommendation, or - when alternative methods are given, use the recommended method, where the EN Eurocodes make a recommendation, - take into account the need for coherence of the Nationally Determined Parameters laid down for the different EN Eurocodes and the various Parts thereof. Member States are encouraged to co-operate to minimize the number of cases where recommendations for a value or method are not adopted for their nationally determined parameters The Nationally Determined Parameters laid down in a Member State should be made clearly known to the users of the EN Eurocodes and other parties concerned, including manufacturers When EN Eurocodes are used for the design of construction works, or parts thereof, the Nationally Determined Parameters of the Member State on whose territory the works are located shall be applied. Note: Any reference to a EN Eurocode design should include the information on which set of Nationally Determined Parameters was used, whether or not the Nationally Determined Parameters that were used correspond to the recommendations given in the EN Eurocodes. GPL was written in relation to the Construction Products Directive (CPD), to which it referred and was issued by the Commission. The CPD has been replaced by the Construction Product Regulation (CPR), and it is the Commission s view that guidance papers are not relevant for a Regulation. However, the Guidance papers remain published documents from the Commission. The documents applicable today are: The Construction Products Regulation (CPR) No. 305/2011 The European Commission Recommendation on the implementation and use of Eurocodes for construction works and structural construction products, Document No. C(2003)4639 (called hereafter Commission Recommendation) The introduction to Annex I of the Construction Products Regulation (CPR) states that: Construction works as a whole and in their separate parts must be fit for their intended use, taking into account in particular the health and safety of persons involved throughout the life cycle of the works. Subject to normal maintenance, construction works must satisfy these basic requirements for construction works for an economically reasonable working life. Page 76/87

77 The Commission Recommendation states: For each Nationally Determined Parameter, the Eurocodes give a recommended value. However, Member States may choose a different specific value as the Nationally Determined Parameter, if they consider it necessary in order to ensure that building and civil engineering works are designed and executed in a way that does not endanger the safety of persons, domestic animals or property. It states also Member States should use the recommended values provided by the Eurocodes when nationally determined parameters have been identified in the Eurocodes. They should diverge from those recommended values only where geographical, geological or climatic conditions or specific levels of protection make that necessary. The excerpts from the Commission Recommendation, based themselves on GPL, represent a clear Commission basis for the NDPs. Page 77/87

78 Annex D Timetable D.1 General This Annex provides timetable for the delivery of all phase 2 tasks (see D.2). All tasks shall provide the final deliverables and background documents by Start Date + 40 months, where the Start Date is defined by agreement with EC/EFTA as 1 January A summary of the stages required in the development of revised and new Eurocode parts is provided in D.3, including the internal Standards development stage numbering. Page 78/87

79 D.2 Timetable for the delivery of tasks Year November December January February March April May June July August September October November December January February Month Month number Preparation Start of the Project (January 1st 2017) x Preparation for Call for experts x x Publication of the call for experts (Dec 19th 2017) x Call for Experts x x x Deadline for applications (Feb 6th 2017) x PT Assesments (preselection teams) x x Final Assesment (March 10th 2017) x Approval by EC/EFTA on PTs x x x Start of the Project Team(s) x End of the Project Team(s) x Administrative (note: important for PTs) Progress report by PT x x x x x x x x x x x Half yearly progress report including latest (as-is) draft(s) by PT x x x x x PT Invoicing of Milestone 0 pre-financing x PT Invoicing of labour costs (Milestones 1, 2 and 3) x x x preparation of consolidated report to EC/EFTA by TC250 mgt. group x x x x x x external audit of consolidated report to EC/EFTA x x x x x x deadline submission of report to EC/EFTA by NEN and CEN x x x EC/EFTA assesment of consolidated report x x x x x x Task specific (the schedule represents the deadlines for these tasks) Start of the Project Team x Preparation of first Draft by PT x x x x x x x x x preparation of background document(s) by PT x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x Delivery of first Draft by PT to NEN x Review of first Draft by SC or WG x x Preparation of Second Draft by PT, taking into account comments from SC or WG x x x x x x x x x x x Delivery of second draft by PT to NEN x review by SC or WG x x preparation of Final Draft by PT, taking into account comments from SC or WG x x x x x Delivery of Final Draft by PT to NEN x Commenting period for NSBs (Enquiry) x x x Preparation of Final document by PT, taking into account comments from NSBs x x Delivery of Background document(s) by PT to NEN x Delivery of Final document by PT to NEN x End of the Project Team x March April May June July August September October November December January February March April May June July August September October November December January February March April May June July August September October November Page 79/87

80 D.3 Standard programmes for drafting work under Mandate M/515 EN A summary of the stages required in the development of revised and new Eurocode parts is provided in Tables D3a, D3b and D3c for the following cases for information: NOTE: D3a: New Eurocode Part D3b: New Eurocode Part using route starting with a Scientific and Policy Report (not a CEN deliverable). This applies to Assessment of existing structures, Glass, FRP and Membrane structures. D3c: Revision of an existing Eurocode Part 1. The TC and SC can at any time during the development of the WI decide (through a formatted Decision) on a tolerance of 9 months at any stage in the process, before stage Only one tolerance is allowed during the development of any WI. 2. Work items financed by EC/EFTA are not monitored against the above-mentioned deadlines but against the dates as stipulated in the relevant contract. Table D3a - New Eurocode Part PT selected. Managing NSB contracts PT to produce EN in stated time and contracts coordination role to TC/SC, if a funded item. SC applies for preliminary WI. stage Work Item activated by TC/SC. Start of 3 year drafting period. See Note 2. stage PT produces 1st working draft of EN for SC review. stage PT produces consolidated final version for enquiry. SC accepts draft as being suitable for enquiry by NSBs and sends draft to CCMC. stage Draft submitted to enquiry and National examination. stage Enquiry closes. stage PT reviews draft and take comments into account new draft pren. SC agrees pren technically competent for launching formal vote. FprEN submitted to CCMC for launch of FV stage FV submitted to FV stage Closure of FV and result stage EN made available by CEN to NSBs (DAV) stage Date of withdrawal DAV plus 12 months. Page 80/87

81 Table D3b - New Eurocode Part using route starting with a Scientific and Policy Report (S and PR). This applies to Assessment of existing structures, Glass, FRP and Membrane structures. Scientific and Policy Report provided to CEN/TC 250 by WG (not mandated by Commission and not a CEN deliverable prepared with industry assistance). CEN/TC 250 asks NSBs for comments on S and PR. CEN/TC 250 considers comments made by NSBs and accepts report as a basis for drafting a Technical Specification (TS). PT selected. Managing NSB contracts PT to produce TS in stated time and contracts coordination role to WG, if a funded item. WG applies for preliminary WI stage Work Item activated by TC. Start of 3 year drafting period. See Note 2. stage PT produces first draft of TS for WG review. stage PT produces second draft of TS for WG review. WG accepts second draft as being suitable for TCA and submits to CCMC. stage Submission to TCA (equivalent to FV in ENs). stage Closure of TCA. stage DAV of TS. stage TS will be used as the basis for conversion into EN. CEN/TC 250 can decide when to activate the WI. SC applies for preliminary WI. stage PT selected. Work Item activated by TC. Start of 3 year drafting period. See Note 2. stage PT produces 1 st working draft of EN for SC review. stage PT produces consolidated final version for enquiry. TC accepts draft as being suitable for enquiry by NSBs and sends draft to CCMC. stage Draft submitted to enquiry and National examination. stage Enquiry closes. stage PT reviews draft and take comments into account new draft pren. SC agrees pren technically competent for launching formal vote (end of SC coordination contract). FprEN submitted to CCMC for launch of FV. stage FV submitted to FV. stage Closure of FV and result. stage Page 81/87

82 EN made available by CEN to NSBs (DAV). stage Date of withdrawal DAV plus 12 months. Table D3c - Revision of an existing Eurocode Part CEN/TC 250 launches 5 year review of existing part for a 6 month enquiry, 5-6 months before anticipated start of contract for revision. PT selected. Managing NSB contracts PT to produce revised EN in stated time and contracts coordination role to TC/SC, if a funded item. SC applies for preliminary WI. stage Work Item activated by TC/SC. Start of 3 year drafting period. See Note 2. stage PT produces 1 st working draft of EN for SC review stage PT produces consolidated final version for enquiry. SC accepts draft as being suitable for enquiry by NSBs and sends draft to CCMC. stage Draft submitted to enquiry and National examination. stage Enquiry closes. stage PT reviews draft and take comments into account new draft pren. TC/SC agrees pren technically competent for launching formal vote. FprEN submitted to CCMC for launch of FV. stage FV submitted to FV. stage Closure of FV and result stage EN made available by CEN to NSBs (DAV). stage Date of withdrawal DAV plus 12 months. Page 82/87

83 Annex E Provisional list of tasks in the complete CEN/TC 250 work programme Table E.1 contains a provisional list of all the tasks in the complete CEN/TC 250 work programme leading to the development of the second generation of EN Eurocodes. The tasks in Phases 3-4 may be subject to change. The table is provided for information only. Table E.1: Provisional list of all the tasks in the CEN/TC 250 work programme Task Ref. Phase Task Name WG7 WG7.T1 P1 Evolution of EN1990 General SC10.T2 P2 Evolution of EN1990 Bridges specific issues SC1 SC1.T1 P1 EN ( Fire) SC1.T2 P2 EN (Snow loads) SC1.T3 P2 EN (Wind) SC1.T4 P2 EN (Thermal actions) SC1.T5 P1 Climate change SC1.T6 P3 Interdependence of climatic actions (wind, snow, thermal and atmospheric icing) and glass structure SC1.T7 P2 EN ( Waves and Currents) SC1.T8 P2 EN (Atmospheric Icing) SC1.T9 P1 EN (Road and rail traffic loads) SC1.T10 P2 EN (Silos and Tanks) SC1.T11 P4 Evolution of existing parts of EN 1991 not included in the other tasks SC2 SC2.T1 P1 New and modified items in EN , EN , EN SC2.T2 P2 New Items in EN SC2.T3 P2 Further new items in EN , EN , EN SC3 SC3.T1 P1 Design of Sections and Members according to EN SC3.T2 P1 Joints and Connections according to EN Page 83/87

84 Task Ref. Phase Task Name SC3.T3 P2 Cold-formed members and sheeting. Revised EN SC3.T4 P2 Stability of Plated Structural Elements. Revised EN SC3.T5 P2 Harmonisation and Extension of Rules for Shells and Similar Structures. Revised EN and EN SC3.T6 P2 Fire design of Steel Structures. Revised EN SC3.T7 P3 Stainless Steels. Revised EN SC3.T8 P3 Steel Fatigue. Revised EN SC3.T9 P3 Material and Fracture. Revised EN SC3.T10 P4 Steel bridges and tension components. Revised EN and EN SC3.T11 P4 Consolidation and rationalisation of EN SC3.T12 P4 Harmonisation and Extension of Rules for Storage Structures. Revised EN and EN SC3.T13 P4 Evolution of existing parts of EN 1993 not included in the other tasks SC4 SC4.T1 P1 Respond to demands from industry, including needs for harmonization with EN1992 and EN1993 SC4.T2 P1 Composite beams with large web openings SC4.T3 P1 Revised rules for shear connection in the presence of modern forms of profiled sheeting SC4.T4 P1 Develop new rules for composite columns (concrete filled tubes) in fire SC4.T5 P2 Development of rules covering shallow floor construction, and other flooring types using precast concrete elements SC4.T6 P3 Extended scope of shear connector and materials guidance to cover current industrial needs SC4.T7 P3 Development of rules for composite frames and prestressed elements SC4.T8 P4 Further harmonization with EN1992 and EN1993 SC5 SC5.T1 P1 New items in revised Eurocode 5, part 1-1 SC5.T2 P1 New Eurocode 5 Part on Timber Concrete Composites SC5.T3 P2 Revisions to Eurocode 5, part 1-1 SC5.T4 P3 Revised Eurocode 5, part 1-2 (Fire) SC5.T5 P3 Revised Eurocode 5, part 1-1 SC5.T6 P4 Evolution of existing parts of EN 1995 not included in the other tasks Page 84/87

85 Task Ref. Phase Task Name SC6 SC6.T1 P1 Revised version of EN SC6.T2 P3 Revised version of EN SC6.T3 P4 Revised version of EN SC6.T4 P2 Revised version of EN SC7 SC7.T1 P1 Harmonization and ease-of-use SC7.T2 P1 General rules SC7.T3 P2 Ground investigation SC7.T4 P2 Foundations, slopes and ground improvement SC7.T5 P2 Retaining structures, anchors, and reinforced ground SC7.T6 P3 Rock mechanics and dynamic design SC8 SC8.T1 P1 Material independent sections of EN SC8.T2 P2 Material dependent sections of EN SC8.T3 P1 Evolution of EN SC8.T4 P2 Evolution of EN SC8.T5 P3 Evolution of EN and EN SC8.T6 P3 Evolution of existing parts of EN 1998 not included in the other tasks SC9 SC9.T1 P1 Update and Simplification of all parts of EN SC9.T2 P1 New types of Connection SC9.T3 P2 Long Span Structures SC9.T5 P3 Facades HG-B HG-B.T1 P1 Bridges - consultation activities and ease of use review HG-B.T2 P3 Bridges - ease of use and technical consistency review HG-F HG-F.T1 P1 Harmonization of fire parts of Structural Eurocodes WG2 WG2.T1 P1 Assessment and Retrofitting of Existing Structures General Rules / Actions Page 85/87

86 Task Ref. Phase Task Name WG2.T2 P3/4 Assessment and Retrofitting of Existing Structures Concrete Structures. This task is solely coordination with SC2 WG2.T3 P4 Assessment and Retrofitting of Existing Structures General Rules / Actions. Preparation of EN WG3 WG3.T1 P1 Structural Glass Preparation of Scientific and Policy Report WG3.T2 P1 Structural Glass Preparation of CEN TS WG3.T3 P4 Structural Glass Preparation of EN WG4 WG4.T1 P1 Fibre Reinforced Polymers Preparation of Scientific and Policy Report WG4.T2 P3 Fibre Reinforced Polymers Preparation of CEN TS WG5 WG5.T1 P1 Membrane Structures Preparation of Scientific and Policy Report WG5.T2 P3 Membrane Structures Preparation of CEN TS WG6 WG6.T1 P1 Robustness Framework WG6.T2 P3 Robustness rules in material related Eurocode parts Note a The tasks in Phase 2 of the work programme which are included in the call for tenders are highlighted in grey. Page 86/87

87 Annex F Mandate M/515 F.1 General This annex contains a copy of Mandate M/515 issued to CEN by the European Commission. The mandate includes reference to two work packages. These work packages have been taken into account in developing the CEN/TC 250 work programme and the requirements for tasks given in this Specification. The TC 250 work programme has not been structured to follow these work packages directly as, in accordance with the mandate itself, the approach used to fulfil the scope of M/515 is for CEN to determine. Page 87/87

88 Ref. Ares(2012) /12/2012 EUROPEAN COMMISSION ENTERPRISE AND INDUSTRY DIRECTORATE-GENERAL Sustainable Growth and EU 2020 Sustainable Industrial Policy and Construction Brussels, 12 December 2012 M/515 EN MANDATE FOR AMENDING EXISTING EUROCODES AND EXTENDING THE SCOPE OF STRUCTURAL EUROCODES 1. BACKGROUND 1.1. Policy framework The Eurocodes have been developed to enable the design of structural construction works (building and civil engineering works) in order to comply with the Essential Requirement n 1 (mechanical resistance and stability) and partially Essential Requirement n 2 (safety in case of fire) and n 4 (safety in use) and to determine the performance of structural construction products. Commission Recommendation (2003/887/EC), on the implementation and use of the Eurocodes for construction works and structural construction products, recommends the Member States to adopt the Eurocodes as a suitable tool for designing construction works and indicates that "continuous efforts to maintain the Eurocodes at the forefront of engineering knowledge and developments in structural design are needed, through further research at MS and at EU level facilitating uptake of the latest scientific knowledge and the development of the construction market, including new materials, products and construction methods". In addition, the Recommendation indicates the need to assess the variations of the Nationally Determined Parameters (NDPs) with the aim of further harmonisation. Application of the Eurocodes in the EU Member States supports the Directive 2006/123/EC of the European Parliament and of the Council of 12 December 2006 on services in the internal market ("Services Directive"). Disparities in design/calculation methods of the national building regulations constitute impediments to the free circulation of engineering and architectural services within the Community. The implementation of the Eurocodes should facilitate the provision of services in the field of construction engineering and architecture by creating conditions for a harmonised system of general rules. To ensure their application over time, the Eurocodes need to be updated to take into account developments on the market (new materials, products, methods, etc). The application of the Eurocodes in the EU Member States supports Public Procurement Directives 2004/17/EC and 2004/18/EC entered into force on 31 st January They state that contracting authorities must allow the use of Responsible official: Manfred Fuchs (manfed.fuchs@ec.europa.eu)