【正文】 IStructE EC2 (Concrete) Design Manual 1 1 Introduction and scope Aims of the Manual This Manual provides guidance on the design of reinforced and prestressed concrete building structures. Structures designed in accordance with this Manual will normally ply with DD ENV 199211: 19921 (hereinafter referred to as EC2). Eurocode system The structural Eurocodes were initiated by the European Commission but are now produced by the Comit233。 Europ233。en de Normalisation (CEN) which is the European standards organization, its members being the national standards bodies of the EU and EFTA countries,. BSI. CEN will eventually publish these design standards as full European Standards EN (Euronorms), but initially they are being issued as Prestandards ENV. Normally an ENV has a life of about 3 years to permit familiarization and trial use of the standard by member states. After formal voting by the member bodies, ENVs are converted into ENs taking into account the national ments on the ENV document. At present the following Eurocode parts have been published as ENVs but as yet none has been converted to an EN: DD ENV 199111: Basis of design and actions on structures (EC1) DD ENV 199211: Design of concrete structures (EC2) DD ENV 199311: Design of steel structures (EC3) DD ENV 199411: Design of posite steel and concrete structures (EC4) DD ENV 199511: Design of timber structures (EC5) DD ENV 199611: Design of masonry structures (EC6) DD ENV 199711: Geotechnical design (EC7) DD ENV 199811: Earthquake resistant design of structures (EC8) DD ENV 199911: Design of aluminium alloy structures (EC9) Each Eurocode is published in a number of parts, usually with ‘General rules’ and ‘Rules for buildings’ in Part 1. The various parts of EC2 are: Part General rules and rules for buildings。 Part Supplementary rules for structural fire design。 Part Supplementary rules for precast concrete elements and structures。 Part Supplementary rules for the use of lightweight aggregate concrete。 IStructE EC2 (Concrete) Design Manual 2 Part Supplementary rules for the use of unbonded and external prestressing tendons。 Part Supplementary rules for plain or lightly reinforced concrete structures。 Part Reinforced and prestressed concrete bridges。 Part Concrete foundations。 Part Liquid retaining and containment structures. All Eurocodes follow a mon editorial style. The codes contain ‘Principles’ and ‘Application rules’. Principles are general statements, definitions, requirements and sometimes analytical models. All designs must ply with the Principles, and no alternative is permitted. Application rules are rules monly adopted in design. They follow the Principles and satisfy their requirements. Alternative rules may be used provided that pliance with the Principles can be demonstrated. Some parameters in Eurocodes are designated by | _ | , monly referred to as boxed values. The boxed values in the Codes are indicative guidance values. Each member state is required to fix the boxed value applicable within its jurisdiction. Such information would be found in the National Application Document (NAD) which is published as part of each ENV. There are also other purposes for NADs. NAD is meant to provide operational information to enable the ENV to be used. For certain aspects of the design, the ENV may refer to national standards or to CEN standard in preparation or ISO standards. The NAD is meant to provide appropriate guidance including modifications required to maintain patibility between the documents. Very occasionally the NAD might rewrite particular clauses of the code in the interest of safety or economy. This is however rare. Scope of the Manual The range of structures and structural elements covered by the Manual is limited to building structures that do not rely on bending in columns for their resistance to horizontal forces and are also nonsway. This will be found to cover the vast majority of all reinforced and prestressed concrete building structures. In using the Manual the following should be noted: ? The Manual has been drafted to ply with ENV 199211 together with the UK NAD ? Although British Standards have been referenced as loading codes in Sections 3 and 6, to ply with the UK NAD, the Manual can be used in conjunction with other loading codes ? The structures are braced and nonsway ? The concrete is of normal weight ? The structure is predominantly in situ ? Prestressed concrete members have bonded or unbonded internal tendons ? The Manual can be used in conjunction with all monly used materials in construction。 however the data given are limited to the following: IStructE EC2 (Concrete) Design Manual 3 – concrete up to characteristic cylinder strength of 50N/mm2 (cube strength 60 2N/mm ) – hightensile reinforcement with characteristic strength of 460 2N/mm – mildsteel reinforcement with characteristic strength of 250 2N/mm – prestressing tendons with 7wire lowrelaxation (Class 2) strands ? High ductility (Class H) has been assumed for: – all ribbed bars and grade 250 bars, and – ribbed wire welded fabric in wire sizes of 6mm or over ? Normal ductility (Class N) has been assumed for plain or indented wire welded fabric. For structures or elements outside this scope EC2 should be used. Contents of the Manual The Manual covers the following design stages: ? general principles that govern the design of the layout of the structure ? initial sizing of members ? estimating of quantities of reinforcement and prestressing tendons ? final design of members. IStructE EC2 (Concrete) Design Manual