外文翻譯---斜拉橋體系

1、<p><b>　　附錄：</b></p><p>　　THE CABLE-STAYED BRIDGE SYSTEM</p><p>　　During the past decade cable-stayed bridges have found wide application, especially in Western Europe, and to a

2、 lesser extent in other parts of the world.</p><p>　　The renewal of the cable-stayed system in modern bridge engineering was due to the tendency of bridge engineers in Europe, primarily Germany, to obtain op

3、timum structural performance from material which was in short supply during the post-war years. </p><p>　　Cable-stayed bridges are constructed along a structural system which comprises an orthotropic deck an

4、d continuous girders which are supported by stays, i.e. inclined cables passing over or attached to towers located at the main piers.</p><p>　　The idea of using cables to support bridge spans is by no means

5、new, and a number of examples of this type of construction were recorded a long time ago .Unfortunately the system in general met with little success, due to the fact that the static were not fully understood and that un

6、suitable materials such as bars and chains were used to form the inclined supports or stays. Stays made in this manner could not be fully tensioned and in a slack condition allowed large deformations of the deck befo<

7、/p><p>　　Wide and successful application of cable-stayed systems was realized only recently, with the introduction of high-strength steels, orthotropic decks, development of welding techniques and progress in s

8、tructural analysis. The development and application of electronic computers opened up new and practically unlimited possibilities for the exact solution of these highly statically indeterminate systems and for precise st

9、atically analysis of their three-dimensional performance.</p><p>　　Existing cable-stayed bridges provide useful data regarding design, fabrication, erection and maintenance of the new system. With the constr

10、uction of these bridges many basic problems encountered in their engineering are shown to have been successfully solved. However, these important data have apparently never before been systematically presented.</p>

11、<p>　　The following factors helped make the successful development of cable-stayed bridges possible:</p><p>　　(1) The development of methods of structural analysis of high statically indeterminate str

12、uctures and application of electronic computers.</p><p>　　(2) The development of orthotropic steel decks.</p><p>　　(3) Experience with previously built bridges containing basic elements of cable

13、-stayed bridges.</p><p>　　(4) Application of high strength steels new methods of fabrication and erection.</p><p>　　(5)The ability to analysis such structures through model studies.</p>&

14、lt;p>　　BASIC CONCEPTS</p><p>　　The application of inclined cables gave a new stimulus to construction of large bridges. The importance of cable-stayed bridges increased rapidly and within only one decade

15、they have become so successful that they have taken their rightful place among classical bridge systems. It is interesting to note how this development which has so revolutionized bridges construction, but which in fact

16、is no new discovery, came out.</p><p>　　The beginning of this system, probably, may be traced on back to the time when it was realized that rigid structures could be formed by joining triangles together.<

17、/p><p>　　Although most of these earlier designs were based on sound principles and assumptions，the girder stiffened by inclined cables suffered various misfortunes which regrettably resulted in abandonment of t

18、he system. Nevertheless, the system in itself was not at all unsuitable. The solution of the problem had unfortunately been attempted in the wrong way.</p><p>　　On the one hand, the equilibrium of these high

19、ly indeterminate systems dad not been clearly appreciated and controlled, and on the other, the tension members were made of timber, round bars or chains. They consisted therefore of low-strength material which was fully

20、 stressed only after a substantial deformation of the girder took place. This may explain why the renewed application of the cable-stayed system was possible only under the following conditions:</p><p>　　The

21、 correct analysis of the structural system.</p><p>　　The use of tension members having under dead load a considerable degree</p><p>　　of stiffness due to high pre-stress and beyond this still su

22、fficient capacity to accommodate the live load.</p><p>　　The use of erection methods which ensure that the design assumptions are</p><p>　　realized in an economic manner.</p><p>　　T

23、he renaissance of the cable-stayed system, however, was finally successfully achieved only during the last decade</p><p>　　Modern cable-stayed bridges present a three-dimensional system consisting of stiffen

24、ing girders, transverse and longitudinal bracings, orthotropic-type deck and supporting parts such as towers in compression and inclined cables in tension. The important characteristics of such a three-dimensional struct

25、ure is the full participation of the transverse construction in the work of the main longitudinal structure. This means a considerable increase in the moment of inertia of the construction which p</p><p>　　T

26、he introduction of the cable-stayed system is a true pioneering development in bridge architecture. Existing cable-stayed bridges are masterpieces of steel construction. They are pleasing in outline, clean in their anato

27、mical conception and totally free of meaningless ornamentation. This is because the design of cable-stayed bridges was governed not only by financial, practical and technical requirements, but also, to a great extent, by

28、 aesthetic and architectural considerations. In the design </p><p>　　These bridges are truly representative of modern times. They are the product of engineering science, which is continuously advancing in ac

29、cordance with its own laws and has been given form and substance by the twentieth century engineer.</p><p>　　From : “Cable-Stayed Bridges Theory and Design” by M. S. Troitsky CrosbLockwood Staples London 199

30、9 </p><p>　　譯文： </p><p><b>　　斜拉橋體系</b></p><p>　　在過去的幾十年中，斜拉橋得到了廣泛的應(yīng)用，尤其是在西歐應(yīng)用最多，在別的地方應(yīng)用也較多。</p><p>　　在現(xiàn)代橋梁工程中，斜拉橋的應(yīng)用之所以興起是由歐洲橋梁工程師的研究方向

31、決定的，大多數(shù)在德國。他們當(dāng)時（二戰(zhàn)后）為了獲得材料的最佳結(jié)構(gòu)使用性能，而在那時這些材料是很緊缺的。</p><p>　　斜拉橋是按如下結(jié)構(gòu)體系建造的，它由正交各向異性橋面板和由拉索控制的連續(xù)梁組成，拉索是通過位于主橋墩上的索塔頂部或固定于索塔頂部的傾斜纜索。</p><p>　　使用拉索來支撐橋跨的觀點現(xiàn)在來說決不是什么新奇的，很早以前就有這種結(jié)構(gòu)的記載。遺憾的是，這中體系的橋很少成功應(yīng)

32、用，主要是因為內(nèi)力并不能完全解出，斜支撐或支座所使用的材料如鋼筋和拉索對斜拉橋來說是不適用的。這種拉索不能充分拉緊而處于松弛狀態(tài)，因而僅在橋面發(fā)生很大變形時，拉索才能承受使用時的拉力。</p><p>　　伴隨著高強度材料和正交各向異性板的產(chǎn)生，焊接技術(shù)的發(fā)展和結(jié)構(gòu)動力性能分析的進步，斜拉橋體系才得到廣泛的發(fā)展并成功的應(yīng)用。電子計算機的應(yīng)用使斜拉橋的高次超靜定體系的精確分析成為可能，并提供了可行的精確的解決方案，

33、也為三維空間結(jié)構(gòu)提供了準(zhǔn)確的靜力分析。</p><p>　　斜拉橋的存在為新體系的設(shè)計、構(gòu)造、建設(shè)和維護提供了有用的數(shù)據(jù)資料，隨著這些橋的興建，在實際工程中遇到的許多基本問題將得到很好的解決。然而，這些重要數(shù)據(jù)以前不能從體系中得出。</p><p>　　以下因素是建造一座斜拉橋應(yīng)該考慮的：</p><p>　　高次超靜定結(jié)構(gòu)性能的分析方法和電子計算機的應(yīng)用。<

34、/p><p>　　正交剛性異性板的發(fā)展。</p><p>　　先前的建橋經(jīng)驗，其中包括斜拉橋的基本組成部分。</p><p>　　高強度鋼材的使用，組裝和施工的新方法。</p><p>　　利用模型分析結(jié)構(gòu)的能力。</p><p><b>　　基本概念</b></p><p>

35、　　斜拉索的應(yīng)用促進了大型橋梁的建設(shè)，斜拉橋的重要性也明顯提高。在過去的僅僅十年內(nèi)，它們在傳統(tǒng)的橋梁體系中已占一席之地，斜拉橋的發(fā)展如此迅猛，真讓人驚嘆，但事實上并沒有新的重大發(fā)現(xiàn)。</p><p>　　這種體系的橋的開始出現(xiàn)可以追溯到那個年代，就是剛性結(jié)構(gòu)可以通過鉸接形成的時代。</p><p>　　盡管早期的大多數(shù)斜拉橋設(shè)計都基于扎實的理論基礎(chǔ)和假設(shè)，由斜拉索控制的主梁還是出了問題，致

36、使人們放棄了該種橋型。然而，這種體系本身并不是不可用的。因為解決問題時不幸地利用了錯誤的假設(shè)方法。</p><p>　　一方面，高次超靜定體系的平衡問題沒有得到足夠的認(rèn)識和控制，另一方面，受壓構(gòu)件由木材﹑圓鋼筋或鋼束組成，他們認(rèn)為只有當(dāng)梁發(fā)生較大的變形時，這些低強度材料應(yīng)力才得以提高。這就是為什么斜拉橋體系在以下條件下才可應(yīng)用：</p><p>　　結(jié)構(gòu)體系的正確分析。</p>

37、<p>　　由于高應(yīng)力存在，使受拉構(gòu)件有相當(dāng)強的剛性，并且當(dāng)超出該應(yīng)力值后，結(jié)構(gòu)還可以有足夠的應(yīng)力儲備去承受活載。</p><p>　　施工方法的選用能保證設(shè)計時的假設(shè)滿足經(jīng)濟可行性的原則。</p><p>　　然而，僅在上個年代斜拉橋體系就可以復(fù)興并最終成功應(yīng)用。</p><p>　　現(xiàn)代斜拉橋由加勁梁﹑橫向和縱向連接系﹑正交異性板和支撐結(jié)構(gòu)如受壓的

38、塔和受拉的索組成，并呈現(xiàn)出三維空間結(jié)構(gòu)。這種三維空間結(jié)構(gòu)的重要特性是橫向結(jié)構(gòu)可以完全參與到縱向主梁的受力中，這意味著大大增大結(jié)構(gòu)的慣性矩，從而做到降低主梁的高度并節(jié)省鋼材。</p><p>　　斜拉橋體系的出現(xiàn)在橋梁美學(xué)上是一個真正的創(chuàng)新，斜拉橋是鋼建筑中的杰作。它們不僅外形美觀，結(jié)構(gòu)概念明確，而且完全沒有多余的裝飾。這時因為斜拉橋的設(shè)計不僅要滿足經(jīng)濟性、可行性和技術(shù)要求，而且在很大程度上要考慮美學(xué)和建筑風(fēng)格。在