【正文】 lapse The two most frequently used design approaches intended to address the issue of progressive collapse are:*c Providing tying capacity *c Checking alternate load pathsFigure 1: Tie Forces in a Frame Structure The first is essentially prescriptive and consists of ensuring that beams, columns, connections and floor (or roof) can act together to provide a specified minimum level of horizontal tying resistance。在過去的幾十年，從來(lái)自世界各地的插圖畫開始，到高高的世貿(mào)中心倒塌為止，這些功能必不可少的為具有代表性的治療和早期的設(shè)計(jì)方法進(jìn)行了綜述。所以問題不是以前認(rèn)為（或只允許在一個(gè)隱式的,基本上復(fù)制過去的令人滿意的性能,方式）開始需要顯式的形式的關(guān)注：需求評(píng)估，模型行為和識(shí)別合適的失效準(zhǔn)則。最終，合理設(shè)計(jì)的預(yù)處理的好處是公認(rèn)的，安全的方法來(lái)安裝燃?xì)庠O(shè)計(jì)然后開始進(jìn)入工業(yè)。圖1，這個(gè)來(lái)自最近的US Guidance，演示了原理。它也可以被使用作為基點(diǎn)為特定結(jié)構(gòu)或特定工作（如法醫(yī)）的更精致的數(shù)字的研究；最好的這些——可能是計(jì)算非?？量痰摹呀?jīng)證明了他們的能力去緊密地復(fù)制的真實(shí)的可觀察的特性。 正是在這樣的背景之下,倫敦帝國(guó)學(xué)院的研究正在進(jìn)行。 2010. 88 pp. 2226. [2] Izzuddin BA, Vlassis AG, Elghazouli AY, and Nethercot DA. Assessment of Progressi ve Collapse of MultiStorey Buildings. Proceedings ICE Structures and Buildings。 2010a [9] Nethercot DA, Blundell D, and Stylianidis P. Progressive Collapse Behaviour of Bare Steel Frames, Ivanyi Conference。 2010 [11] Stylianidis PM, PhD Thesis, Department of Civil and Environmental Engineering, Imperial College London, in Preparation。 2008, Vol. 30, No. 5, pp. 13081318. [4] Izzuddin BA, Vlassis AG, Elghazouli AY, and Nethercot DA. Progressive Collapse of MultiStorey Buildings due to Sudden Column Loss Part II, Applications Engineering Structures。盡管出發(fā)點(diǎn)是柱移動(dòng)，但該方法包含一些獨(dú)特的特性：*c 雖然動(dòng)態(tài)反應(yīng)是被允許的，但是只有靜態(tài)分析是必需的（Izzuddin et al 2007）。*c 它包括總變形，發(fā)生大應(yīng)變，導(dǎo)致非彈性行為和幾何效果的改變一樣。這是不可能的，連系材料應(yīng)該通過樓板和屋蓋。后來(lái)，連續(xù)倒塌的發(fā)生率如同Murragh Building和世貿(mào)中心帶來(lái)增加如何合理地考慮那些結(jié)構(gòu)的設(shè)計(jì)實(shí)際現(xiàn)象和問題的關(guān)注，它被認(rèn)為是合適的。舉一個(gè)具體的例子：設(shè)計(jì)充分耐火鋼框架建筑開始(已經(jīng)被認(rèn)可的)和簡(jiǎn)單的法定規(guī)則對(duì)混凝土外層脆弱的構(gòu)件。說(shuō)明性的結(jié)果是用來(lái)幫助發(fā)現(xiàn)一些關(guān)鍵的管理功能，去展示如何定量比較安排現(xiàn)在可能使和說(shuō)明赫爾墨斯的一些以前的設(shè)計(jì)概念之間的不同來(lái)直接改善抗倒性。 Nethercot et al 2010b) have suggested that tying capacity correlates poorly with actual resistance to progressive collapse. Moreover, being prescriptive, it does not permit the meaningful parison of alternative arrangements a fundamental feature of structural design. In its most frequently used form the alternative load path approach presumes the instantaneous loss of a single column and then requires that the ability of the resulting damaged structure to bridge the loss be demonstrated by suitable calculation (Gudmundsson and Izzuddin 2010). The approach may be implemented at varying levels of sophistication in terms of the analysis。 Progressive Collapse。 where these require putations beyond “hand methods”, these should be based on the use of available analysis software.*c A realistic and recognisable criterion of failure should be used.*c Approach should permit study of cause and effect and be suitable for the making of quantitative parisons. It was against this background that the studies at Imperial College London have been undertaken. An approach incorporating the three essential features but observing the five desirable features was originally developed (Vlassis 2007)。*c 加強(qiáng)能力從工藝為基礎(chǔ)的移動(dòng)科學(xué)依據(jù)從而從規(guī)范的定量合理的方法。在羅南點(diǎn)于1968年在倫敦坍塌之前，魯棒性原則，抗連續(xù)性倒塌，非比例破壞等是不屬于工程詞匯里的。本文將回顧當(dāng)前用來(lái)設(shè)計(jì)抵制連續(xù)倒塌的方法和對(duì)比過去七年在倫敦大學(xué)帝國(guó)理工學(xué)院進(jìn)行的這些工作，那里的目標(biāo)是提供一個(gè)依據(jù)于實(shí)際方法適合用在常規(guī)設(shè)計(jì)。此外，它被規(guī)范不允許有意義的替代安排的比較——結(jié)構(gòu)設(shè)計(jì)的一個(gè)基本特征。*c 任何必需的驗(yàn)定都應(yīng)該利用熟悉的技術(shù)；這里需要的計(jì)算多于“手工”，是基于可用的分析軟件的使用的計(jì)算。*c 該方法可以實(shí)現(xiàn)只使用顯式公式，從而允許簡(jiǎn)單和快速計(jì)算。 2010, 7 – 10 Sept, pp. 515. [7] Nethercot DA, Stylianidis P, Izzuddin BA, and Elghazouli AY. Enhancing the Robustness of Steel and Composite Buildings, ICASS’09 Hong Kong。 2007