【正文】 25 35 100 35 Slabs with ribbed open soffit and no stirrups thickness* width of ribs cover 150 150 55 115 110 35 90 90 35 *Thickness of structural topping plus any nonbustible screed. ?Cover is to main reinforcement. Table Basic ratios of span/effective depth for initial design (ykf = 460 2N/mm ) IStructE EC2 (Concrete) Design Manual 12 Structural system Span/effective depth ratio Beam Slab 1． Simply supported beam Oneway or twoway spanning simply supported slab 2． End span of: continuous beam。 Part Supplementary rules for plain or lightly reinforced concrete structures。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。 Part Reinforced and prestressed concrete bridges。 oneway continuous slab。目前以下歐洲規(guī)范部分已刊登于 歐洲試用標(biāo)準(zhǔn)協(xié)會(huì) ，但目前還沒(méi)有一個(gè)轉(zhuǎn)換為 歐洲標(biāo)準(zhǔn) 的： DD ENV 199111： 基礎(chǔ)設(shè)計(jì)和結(jié)構(gòu) 功能 （ EC1） DD ENV 199211： 混凝土結(jié)構(gòu)設(shè)計(jì)（ EC2） DD ENV 199311： 鋼結(jié)構(gòu)設(shè)計(jì)（ EC3） DD ENV 199411： 復(fù)合鋼設(shè)計(jì)和混凝土結(jié)構(gòu)（ EC4） DD ENV 199511： 木結(jié)構(gòu)設(shè)計(jì)（ EC5） DD ENV 199611： 砌體結(jié)構(gòu)設(shè)計(jì)（ EC6） DD ENV 199711： 巖土工程設(shè)計(jì)（ EC7） DD ENV 199811： 抗震結(jié)構(gòu)設(shè)計(jì)（ EC8） DD ENV 199911： 鋁合金結(jié)構(gòu)設(shè)計(jì)（ EC9） 每一個(gè)歐洲規(guī)范都出版了一部分，在第 1 部分通常用 ‘一般規(guī)則 ’和 ‘建筑規(guī)則 ’。所有設(shè)計(jì)都必須遵守原則，并沒(méi)有其他選擇， 同時(shí) 也是不允許的。 國(guó)家 應(yīng)用文件是指提供可行的資料使 歐洲試用規(guī)范 得以使用。結(jié)構(gòu)或分子在這個(gè)范圍之外的 混凝土結(jié)構(gòu)設(shè)計(jì) 應(yīng)當(dāng)使用。關(guān)鍵位置大致可由核心墻圍護(hù)的樓梯所提供，電梯及服務(wù)管道。 如果 結(jié)構(gòu)分伸縮縫，那每一部分應(yīng)采用獨(dú)立的結(jié)構(gòu)設(shè)計(jì) 使其 能夠保持穩(wěn)定和強(qiáng)勁并且不依靠穩(wěn)定部分。結(jié)構(gòu)在雙方的結(jié)合處加外框。 IStructE EC2 (Concrete) Design Manual 18 圖 焊縫的位置 設(shè)計(jì)應(yīng)考慮到結(jié)構(gòu)可能的 性能的下降 及 它們 部件所處環(huán)境，適當(dāng)考慮到預(yù)期的維修。 極限狀態(tài) 這本手冊(cè)在 混凝土結(jié)構(gòu)設(shè)計(jì) 中 采用了極限狀態(tài)的原則與局部因素的形式。強(qiáng)度標(biāo)準(zhǔn)值是 C20/25， C25/30， C30/37，C35/45， C40/50， C45/55 和 C50/60。 應(yīng)該 避免冗長(zhǎng)的分析方法。 荷載 應(yīng)是由最短和最直接的路線傳遞到基礎(chǔ) 上 的。 規(guī)范建設(shè)項(xiàng) 目通常會(huì)更 節(jié)省 ，而且提供會(huì)比專用物品更方便?；A(chǔ)設(shè)計(jì)是最好推遲到可評(píng)價(jià)現(xiàn)場(chǎng)調(diào)查結(jié)果 出來(lái) 以后的階段。 混凝土局部承載力使用 為最終極限狀態(tài)和 為使用極限狀態(tài)。 ‘不 利的 ’和 ‘有利 的 ’ 的因素 應(yīng)該被 使用 這樣會(huì) 產(chǎn)生最 有依據(jù)的情況 。 應(yīng) 保證 適當(dāng)?shù)幕炷临|(zhì)量 可以 使之具有足夠的 可靠度 。 也許還需要有一個(gè)顯著變化的類型基礎(chǔ)或同樣高度伸縮縫的結(jié)構(gòu)。 一個(gè)設(shè)計(jì)完善以及細(xì) 部完整 的結(jié)構(gòu)通常會(huì)滿足在第 部分詳細(xì)的要求。重心和剪力墻宜分布在整個(gè)結(jié)構(gòu)上，這樣安排他們的結(jié)合剪切中心大約位于傾覆力矩線上。 IStructE EC2 (Concrete) Design Manual 16 第二章 一般原則 本節(jié)概述了一般的原則，既適用于鋼筋和預(yù)應(yīng)力混凝土建筑結(jié)構(gòu)的初始和最終設(shè)計(jì) 階段 ，而且 又適用于 各國(guó)設(shè)計(jì)參數(shù)管理所有階段。 國(guó)家 應(yīng)用文件是為了提供適當(dāng)?shù)闹笇?dǎo)，包括修改規(guī)定，以維持文件之間的兼容性。他們遵循的各項(xiàng)原則和滿足他們的要求。 所有 的歐洲規(guī)范都 遵循一個(gè)共同的編寫風(fēng)格。 oneway or twosay spanning slab 4． Slab supported on columns without beams (flat slab), based on longer span 5． Cantilever 15 21 20 27 21 30 26 6 8 Notes to Table 1. For twoway spanning slabs (supported on beams), the check on the ratio of span/effective depth should be carried out on the shorter span. For flat slabs, the longer span should be taken. 2. For flanged sections with the ratio of the flange to the rib width greater than 3, the Table value should be multiplied by . 3. For members, other than flat slab panels, which support partitions liable to be damaged by excessive deflection of the member, and where the span exceeds 7m, the Table value should be multiplied by 7/span. 4. For flat slabs where the greater span exceeds , the Table value should be multiplied by IStructE EC2 (Concrete) Design Manual 13 第一章 引言和適用 范圍 手冊(cè)的作用 這本手冊(cè)為設(shè)計(jì)鋼筋和預(yù)應(yīng)力混凝土建筑結(jié)構(gòu)提供了指導(dǎo)。 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