土木工程外文翻譯---高層結構與鋼結構

1、<p>　　第五部分 英文論文翻譯</p><p>　　Talling building and Steel construction</p><p>　　Although there have been many advancements in building construction technology in general. Spectacular archievem

2、ents have been made in the design and construction of ultrahigh-rise buildings.</p><p>　　The early development of high-rise buildings began with structural steel framing.Reinforced concrete and stressed-skin

3、 tube systems have since been economically and competitively used in a number of structures for both residential and commercial purposes.The high-rise buildings ranging from 50 to 110 stories that are being built all ove

4、r the United States are the result of innovations and development of new structual systems.</p><p>　　Greater height entails increased column and beam sizes to make buildings more rigid so that under wind loa

5、d they will not sway beyond an acceptable limit.Excessive lateral sway may cause serious recurring damage to partitions,ceilings.and other architectural details. In addition,excessive sway may cause discomfort to the occ

6、upants of the building because their perception of such motion.Structural systems of reinforced concrete,as well as steel,take full advantage of inherent potential stiffness </p><p>　　In a steel structure,fo

7、r example,the economy can be defined in terms of the total average quantity of steel per square foot of floor area of the building.Curve A in Fig .1 represents the average unit weight of a conventional frame with increa

8、sing numbers of stories. Curve B represents the average steel weight if the frame is protected from all lateral loads. The gap between the upper boundary and the lower boundary represents the premium for height for the t

9、raditional column-and-beam frame.Stru</p><p>　　Systems in steel. Tall buildings in steel developed as a result of several types of structural innovations. The innovations have been applied to the constructi

10、on of both office and apartment buildings.</p><p>　　Frame with rigid belt trusses. In order to tie the exterior columns of a frame structure to the interior vertical trusses,a system of rigid belt trusses a

11、t mid-height and at the top of the building may be used. A good example of this system is the First Wisconsin Bank Building(1974) in Milwaukee.</p><p>　　Framed tube. The maximum efficiency of the total struc

12、ture of a tall building, for both strength and stiffness,to resist wind load can be achieved only if all column element can be connected to each other in such a way that the entire building acts as a hollow tube or rigid

13、 box in projecting out of the ground. This particular structural system was probably used for the first time in the 43-story reinforced concrete DeWitt Chestnut Apartment Building in Chicago. The most significant use of

14、this s</p><p>　　Column-diagonal truss tube. The exterior columns of a building can be spaced reasonably far apart and yet be made to work together as a tube by connecting them with diagonal members interest

15、ing at the centre line of the columns and beams. This simple yet extremely efficient system was used for the first time on the John Hancock Centre in Chicago, using as much steel as is normally needed for a traditional 4

16、0-story building.</p><p>　　Bundled tube. With the continuing need for larger and taller buildings, the framed tube or the column-diagonal truss tube may be used in a bundled form to create larger tube envelo

17、pes while maintaining high efficiency. The 110-story Sears Roebuck Headquarters Building in Chicago has nine tube, bundled at the base of the building in three rows. Some of these individual tubes terminate at different

18、heights of the building, demonstrating the unlimited architectural possibilities of this latest stru</p><p>　　Stressed-skin tube system. The tube structural system was developed for improving the resistance

19、to lateral forces (wind and earthquake) and the control of drift (lateral building movement ) in high-rise building. The stressed-skin tube takes the tube system a step further. The development of the stressed-skin tube

20、utilizes the fa?ade of the building as a structural element which acts with the framed tube, thus providing an efficient way of resisting lateral loads in high-rise buildings, and re</p><p>　　Because of the

21、 contribution of the stressed-skin fa?ade, the framed members of the tube require less mass, and are thus lighter and less expensive. All the typical columns and spandrel beams are standard rolled shapes,minimizing the u

22、se and cost of special built-up members. The depth requirement for the perimeter spandrel beams is also reduced, and the need for upset beams above floors, which would encroach on valuable space, is minimized. The struct

23、ural system has been used on the 54-story One </p><p>　　Systems in concrete. While tall buildings constructed of steel had an early start, development of tall buildings of reinforced concrete progressed at a

24、 fast enough rate to provide a competitive chanllenge to structural steel systems for both office and apartment buildings.</p><p>　　Framed tube. As discussed above, the first framed tube concept for tall bui

25、ldings was used for the 43-story DeWitt Chestnut Apartment Building. In this building ,exterior columns were spaced at 5.5ft (1.68m) centers, and interior columns were used as needed to support the 8-in . -thick (20-m) f

26、lat-plate concrete slabs.</p><p>　　Tube in tube. Another system in reinforced concrete for office buildings combines the traditional shear wall construction with an exterior framed tube. The system consists

27、of an outer framed tube of very closely spaced columns and an interior rigid shear wall tube enclosing the central service area. The system (Fig .2), known as the tube-in-tube system , made it possible to design the worl

28、d’s present tallest (714ft or 218m)lightweight concrete building ( the 52-story One Shell Plaza Building in </p><p>　　Systems combining both concrete and steel have also been developed, an examle of which is

29、 the composite system developed by skidmore, Owings &Merril in which an exterior closely spaced framed tube in concrete envelops an interior steel framing, thereby combining the advantages of both reinforced concrete

30、 and structural steel systems. The 52-story One Shell Square Building in New Orleans is based on this system.</p><p>　　Steel construction refers to a broad range of building construction in which steel pla

31、ys the leading role. Most steel construction consists of large-scale buildings or engineering works, with the steel generally in the form of beams, girders, bars, plates, and other members shaped through the hot-rolled p

32、rocess. Despite the increased use of other materials, steel construction remained a major outlet for the steel industries of the U.S, U.K, U.S.S.R, Japan, West German, France, and other steel </p><p>　　Early

33、 history. The history of steel construction begins paradoxically several decades before the introduction of the Bessemer and the Siemens-Martin (openj-hearth) processes made it possible to produce steel in quantities suf

34、ficient for structure use. Many of problems of steel construction were studied earlier in connection with iron construction, which began with the Coalbrookdale Bridge, built in cast iron over the Severn River in England

35、in 1777. This and subsequent iron bridge work, in addit</p><p>　　The technique for passing iron, heated to the plastic state, between rolls to form flat and rounded bars, was developed as early as 1800;by 18

36、19 angle irons were rolled; and in 1849 the first I beams, 17.7 feet (5.4m) long , were fabricated as roof girders for a Paris railroad station.</p><p>　　Two years later Joseph Paxton of England built the Cr

37、ystal Palace for the London Exposition of 1851. He is said to have conceived the idea of cage construction-using relatively slender iron beams as a skeleton for the glass walls of a large, open structure. Resistance to w

38、ind forces in the Crystal palace was provided by diagonal iron rods. Two feature are particularly important in the history of metal construction; first, the use of latticed girder, which are small trusses, a form first d

39、evelope</p><p>　　In 1853 the first metal floor beams were rolled for the Cooper Union Building in New York. In the light of the principal market demand for iron beams at the time, it is not surprising that t

40、he Cooper Union beams closely resembled railroad rails.</p><p>　　The development of the Bessemer and Siemens-Martin processes in the 1850s and 1860s suddenly open the way to the use of steel for structural p

41、urpose. Stronger than iron in both tension and compression ,the newly available metal was seized on by imaginative engineers, notably by those involved in building the great number of heavy railroad bridges then in deman

42、d in Britain, Europe, and the U.S.</p><p>　　A notable example was the Eads Bridge, also known as the St. Louis Bridge, in St. Louis (1867-1874), in which tubular steel ribs were used to form arches with a sp

43、an of more than 500ft (152.5m). In Britain, the Firth of Forth cantilever bridge (1883-90) employed tubular struts, some 12 ft (3.66m) in diameter and 350 ft (107m) long. Such bridges and other structures were important

44、in leading to the development and enforcement of standards and codification of permissible design stresses. The lack </p><p>　　The possibilities inherent in metal construction for high-rise building was demo

45、nstrated to the world by the Paris Exposition of 1889.for which Alexandre-Gustave Eiffel, a leading French bridge engineer, erected an openwork metal tower 300m (984 ft) high. Not only was the height-more than double tha

46、t of the Great Pyramid-remarkable, but the speed of erection and low cost were even more so, a small crew completed the work in a few months. </p><p>　　The first skyscrapers. Meantime, in the United States a

47、nother important development was taking place. In 1884-85 Maj. William Le Baron Jenney, a Chicago engineer , had designed the Home Insurance Building, ten stories high, with a metal skeleton. Jenney’s beams were of Besse

48、mer steel, though his columns were cast iron. Cast iron lintels supporting masonry over window openings were, in turn, supported on the cast iron columns. Soild masonry court and party walls provided lateral support agai

49、nst w</p><p>　　Though the new construction form was to remain centred almost entirely in America for several decade, its impact on the steel industry was worldwide. By the last years of the 19th century, the

50、 basic structural shapes-I beams up to 20 in. ( 0.508m) in depth and Z and T shapes of lesser proportions were readily available, to combine with plates of several widths and thicknesses to make efficient members of any

51、required size and strength. In 1885 the heaviest structural shape produced through hot-r</p><p>　　Coincident with the introduction of structural steel came the introduction of the Otis electric elevator in 1

52、889. The demonstration of a safe passenger elevator, together with that of a safe and economical steel construction method, sent building heights soaring. In New York the 286-ft (87.2-m) Flatiron Building of 1902 was sur

53、passed in 1904 by the 375-ft (115-m) Times Building ( renamed the Allied Chemical Building) , the 468-ft (143-m) City Investing Company Building in Wall Street, the 612-ft</p><p>　　The rapid increase in heig

54、ht and the height-to-width ratio brought problems. To limit street congestion, building setback design was prescribed. On the technical side, the problem of lateral support was studied. A diagonal bracing system, such as

55、 that used in the Eiffel Tower, was not architecturally desirable in offices relying on sunlight for illumination. The answer was found in greater reliance on the bending resistance of certain individual beams and column

56、s strategically designed into the </p><p>　　World War I brought an interruption to the boom in what had come to be called skyscrapers (the origin of the word is uncertain), but in the 1920s New York saw a re

57、sumption of the height race, culminating in the Empire State Building in the 1931. The Empire State’s 102 stories (1,250ft. [381m]) were to keep it established as the hightest building in the world for the next 40 years.

58、 Its speed of the erection demonstrated how thoroughly the new construction technique had been mastered. A depot acro</p><p>　　The worldwide depression of the 1930s and World War II provided another interrup

59、tion to steel construction development, but at the same time the introduction of welding to replace riveting provided an important advance.</p><p>　　Joining of steel parts by metal are welding had been succe

60、ssfully achieved by the end of the 19th century and was used in emergency ship repairs during World War I, but its application to construction was limited until after World War II. Another advance in the same area had be

61、en the introduction of high-strength bolts to replace rivets in field connections.</p><p>　　Since the close of World War II, research in Europe, the U.S., and Japan has greatly extended knowledge of the beha

62、vior of different types of structural steel under varying stresses, including those exceeding the yield point, making possible more refined and systematic analysis. This in turn has led to the adoption of more liberal de

63、sign codes in most countries, more imaginative design made possible by so-called plastic design ?The introduction of the computer by short-cutting tedious paperwork,</p><p><b>　　高層結構與鋼結構</b></

64、p><p>　　近年來，盡管一般的建筑結構設計取得了很大的進步，但是取得顯著成績的還要屬超高層建筑結構設計。</p><p>　　最初的高層建筑設計是從鋼結構的設計開始的。鋼筋混凝土和受力外包鋼筒系統(tǒng)運用起來是比較經(jīng)濟的系統(tǒng)，被有效地運用于大批的民用建筑和商業(yè)建筑中。50層到100層的建筑被定義為超高層建筑。而這種建筑在美國得廣泛的應用是由于新的結構系統(tǒng)的發(fā)展和創(chuàng)新。</p>&

65、lt;p>　　這樣的高度需要增大柱和梁的尺寸，這樣以來可以使建筑物更加堅固以至于在允許的限度范圍內承受風荷載而不產(chǎn)生彎曲和傾斜。過分的傾斜會導致建筑的隔離構件、頂棚以及其他建筑細部產(chǎn)生循環(huán)破壞。除此之外，過大的搖動也會使建筑的使用者們因感覺到這樣的的晃動而產(chǎn)生不舒服的感覺。無論是鋼筋混凝土結構系統(tǒng)還是鋼結構系統(tǒng)都充分利用了整個建筑的剛度潛力，因此不能指望利用多余的剛度來限制側向位移。</p><p>　　在

66、鋼結構系統(tǒng)設計中，經(jīng)濟預算是根據(jù)每平方英寸地板面積上的鋼材的數(shù)量確定的。圖示1中的曲線A顯示了常規(guī)框架的平均單位的重量隨著樓層數(shù)的增加而增加的情況。而曲線B顯示則顯示的是在框架被保護而不受任何側向荷載的情況下的鋼材的平均重量。上界和下界之間的區(qū)域顯示的是傳統(tǒng)梁柱框架的造價隨高度而變化的情況。而結構工程師改進結構系統(tǒng)的目的就是減少這部分造價。</p><p>　　鋼結構中的體系：鋼結構的高層建筑的發(fā)展是幾種結構體系

67、創(chuàng)新的結果。這些創(chuàng)新的結構已經(jīng)被廣泛地應用于辦公大樓和公寓建筑中。</p><p>　　剛性帶式桁架的框架結構：為了聯(lián)系框架結構的外柱和內部帶式桁架，可以在建筑物的中間和頂部設置剛性帶式桁架。1974年在米望基建造的威斯康森銀行大樓就是一個很好的例子。</p><p>　　框架筒結構： 如果所有的構件都用某種方式互相聯(lián)系在一起，整個建筑就像是從地面發(fā)射出的一個空心筒體或是一個剛性盒子一樣。

68、這個時候此高層建筑的整個結構抵抗風荷載的所有強度和剛度將達到最大的效率。這種特殊的結構體系首次被芝加哥的43層鋼筋混凝土的德威特紅棕色的公寓大樓所采用。但是這種結構體系的的所有應用中最引人注目的還要屬在紐約建造的100層的雙筒結構的世界貿易中心大廈。</p><p>　　斜撐桁架筒體： 建筑物的外柱可以彼此獨立的間隔布置，也可以借助于通過梁柱中心線的交叉的斜撐構件聯(lián)系在一起，形成一個共同工作的筒體結構。這種高度的

69、結構體系首次被芝加哥的John Hancock 中心大廈采用。這項工程所耗用的剛才量與傳統(tǒng)的四十層高樓的用鋼量相當。</p><p>　　筒體： 隨著對更高層建筑的要求不斷地增大。筒體結構和斜撐桁架筒體被設計成捆束狀以形成更大的筒體來保持建筑物的高效能。芝加哥的110層的Sears Roebuck 總部大樓有9個筒體，從基礎開始分成三個部分。這些獨立筒體中的終端處在不同高度的建筑體中，這充分體現(xiàn)出了這種新式結構觀

70、念的建筑風格自由化的潛能。這座建筑物1450英尺（442米）高，是世界上最高的大廈。</p><p>　　薄殼筒體系統(tǒng)：這種筒體結構系統(tǒng)的設計是為了增強超高層建筑抵抗側力的能力（風荷載和地震荷載）以及建筑的抗側移能力。薄殼筒體是筒體系統(tǒng)的又一大飛躍。薄殼筒體的進步是利用高層建筑的正面（墻體和板）作為與筒體共同作用的結構構件，為高層建筑抵抗側向荷載提供了一個有效的途徑，而且可獲得不用設柱，成本較低，使用面積與建筑面

71、積之比又大的室內空間。</p><p>　　由于薄殼立面的貢獻，整個框架筒的構件無需過大的質量。這樣以來使得結構既輕巧又經(jīng)濟。所有的典型柱和窗下墻托梁都是軋制型材，最大程度上減小了組合構件的使用和耗費。托梁周圍的厚度也可適當?shù)臏p小。而可能占據(jù)寶貴空間的墻上鐓梁的尺寸也可以最大程度地得到控制。這種結構體系已被建造在匹茲堡洲的One Mellon銀行中心所運用。</p><p>　　鋼筋混凝土

72、中的各體系：雖然鋼結構的高層建筑起步比較早，但是鋼筋混凝土的高層建筑的發(fā)展非?？欤瑹o論在辦公大樓還是公寓住宅方面都成為剛結構體系的有力競爭對手。</p><p>　　框架筒：像上面所提到的，框架筒構思首次被43層的迪威斯公寓大樓所采用。在這座大樓中，外柱的柱距為5.5英尺（1.68米）。而內柱則需要支撐8英寸厚的無梁板。</p><p>　　筒中筒結構：另一種針對于辦公大樓的鋼筋混凝土體系

73、把傳統(tǒng)的剪力墻結構與外框架筒相結合。該體系由柱距很小的外框架與圍繞中心設備區(qū)的剛性剪力墻筒組成。這種筒中筒結構（如插圖2）使得當前世界上最高的輕質混凝土大樓（在休斯頓建造的獨殼購物中心大廈）的整體造價只與35層的傳統(tǒng)剪力墻結構相當。</p><p>　　鋼結構與混凝土結構的聯(lián)合體系也有所發(fā)展。Skidmore ,Owings 和Merrill共同設計的混合體系就是一個好例子。在此體系中，外部的混凝土框架筒包圍著內

74、部的鋼框架，從而結合了鋼筋混凝土體系與鋼結構體系各自的優(yōu)點。在新奧爾良建造的52層的獨殼廣場大廈就是運用了這種體系。</p><p>　　鋼結構是指在建筑物結構中鋼材起著主導作用的結構，是一個很寬泛的概念。大部分的鋼結構都包括建筑設計，工程技術、工藝。通常還包括以主梁、次梁、桿件，板等形式存在的鋼的熱軋加工工藝。上個世紀七十年代，除了對其他材料的需求在增長，鋼結構仍然保持著對于來自美國、英國、日本、西德、法國等國

75、家的鋼材廠鋼材的大量需求。</p><p>　　發(fā)展歷史：早在Bessemer和Siemens-Marton(開放式爐)工藝出現(xiàn)以前，鋼結構就已經(jīng)有幾十年的歷史了。而直到此工藝問世之后才使得鋼材可以大批生產(chǎn)出來供結構所用。對鋼結構諸多問題的研究開始于鐵結構的使用，當時很著名的研究對象是1977年在英國建造的橫跨斯沃河的Coalbrook dale 大橋。這座大橋以及后來的鐵橋設計再加上蒸汽鍋爐、鐵船身的設計都刺激

76、了建筑安裝設計以及連接工藝的發(fā)展。鐵結構對材料的需求量較小是優(yōu)勝于磚石結構的主要方面。長久以來一直用木材制作的三角桁架也換成鐵制的了。承受由直接荷載產(chǎn)生的重力作用的受壓構件常用鑄鐵制造，而承受由懸掛荷載產(chǎn)生的推力作用的受拉構件常用熟鐵制造。</p><p>　　把鐵加熱到塑性狀態(tài)，使之從卷狀轉化為扁平狀與圓狀之間的某一狀態(tài)的工藝，早在1800年就得以發(fā)展了。隨后，1819年角鋼問世，1894年第一個工字鋼被建造出

77、來作為巴黎火車站的頂梁。此工字鋼長17.7英尺）（5.4米）。</p><p>　　1851年英國的Joseph Paxtond為倫敦博覽會建造了水晶宮。據(jù)說當時他已有這樣的骨架結構構思：用比較細的鐵梁作為玻璃幕墻的骨架。此建筑的風荷載抵抗力是由對角拉桿所提供的。在金屬結構的發(fā)展歷史中，有兩個標志性事件：首先是從木橋發(fā)展而來的格構梁由木制轉化為鐵制；其次是鍛鐵制的受拉構件與鑄鐵制的受壓構件受熱后通過鉚釘連接工藝的

78、發(fā)展。</p><p>　　十九世紀五六十年代，Bessemer 與 Siemens-Martin工藝的發(fā)展使鋼材的生產(chǎn)能滿足結構的需求。鋼的受拉強度與受壓強度都好于鐵。這種新型的金屬常被有想象力的工程師所利用，尤其倍受那些參與過英國、歐洲以及美國的道橋建設的工程師的喜愛。</p><p>　　其中一個很好的例子就是Eads大橋（也被稱為路易斯洲大橋）（1867-1874）。在這座大橋中，

79、每隔500英尺（152.5米）設有由鋼管加強肋形成的拱。英國的Firth of Forth懸索橋設有管件支撐，直徑大約為12英尺（3.66米），長度為350英尺（107）米。這些大橋以及其他結構在引導鋼結構的發(fā)展，規(guī)范的實施，許用應力的設計方面起到了很重要的作用。1907年Quebec懸索大橋的偶然破壞揭露了二十世紀初期由于缺乏足夠的理論知識，甚至是缺乏足夠的理論研究的基礎知識，而導致在應力分析方面出現(xiàn)了很多的不足。但是，這樣的損壞卻很

80、少出現(xiàn)在金屬骨架的辦公大樓中。因為盡管在缺乏縝密的分析的情況下，這些建筑也表現(xiàn)出了很高的實用性。在上個世紀中葉，沒有經(jīng)過任何特殊合金強化、硬化過的普通碳素鋼已經(jīng)被廣泛地使用了。</p><p>　　在1889年巴黎召開的世界博覽會上，金屬結構表現(xiàn)出了在超高層建筑運用上的內在潛力。在這次會上，法國著名的橋梁設計師埃非爾展示了他的杰作-300米高的露天開挖的鐵塔。無論是它的高度（比著名的金字塔的兩倍還高），架設的速度

81、-人數(shù)不多的工作人員僅用幾個月的時間就完成了整個工程任務，還是很低的工程造價都使它脫穎而出。</p><p>　　首批摩天大廈：在剛結構發(fā)展的同時，美國的另一個是也蓬勃的發(fā)展起來了。1884-1885年，芝加哥的工程師Maj.William Le Baron Jennny設計了家庭保險公司大廈。這座大廈也是金屬結構的，有十層高。大廈的梁是鋼制的，而柱是鑄鐵所制。鑄鐵制的過梁支撐著窗洞口上方的砌體，同時也需要鑄鐵制

82、的柱支撐著。實心砌體的天井與界墻提供抵抗風載的側向支撐。不到十年的功夫，芝加哥和紐約已經(jīng)有超過30座辦公大樓是利用這種結構。鋼材在這些結構中起了非常大的作用。這種結構利用鉚釘把梁與柱連接在一起。有時為了抵抗風荷載還是在豎向構件和橫向構件的連接點出貼覆上節(jié)點板來加固結構。此外，輕型的玻璃幕墻結構代替了老式的重質砌體結構。</p><p>　　盡管幾十年來之中建筑形式主要是在美國發(fā)展的，但是它卻影響著全世界鋼材工業(yè)的

83、發(fā)展。十九世紀的最后幾年，基本結構形狀工字型鋼的厚度已經(jīng)達到20英寸（0.508米），非對稱的Z字型鋼和T型鋼可以與有一定寬度和厚度的板相聯(lián)結，使得構件具體符合要求的尺寸和強度。1885年最重的型鋼通過熱軋生產(chǎn)出來，每英寸不到100磅（45千克）。到二十世紀六十年代這個數(shù)字已經(jīng)達到每英寸700磅（320千克）。</p><p>　　緊隨著鋼結構的發(fā)展，1988年第一部電梯問世了。安全載客電梯誕生，以及安全經(jīng)濟的鋼

84、結構設計方法的發(fā)展促使建筑高度迅猛增加。1902年在紐約建造的高286英寸（87.2米）的Flatiron大廈不斷地被后來的建筑所超越。這些建筑分別是高375英尺（115米）的時代大廈（1904），（后來改名為聯(lián)合化工制品大廈）。1908年在華爾街建造的高468英尺（143米）的城市投資公司大廈，高612 英尺（187米）的星爾大廈，以及700英尺（214米）的都市塔和780英尺高（232米）的Woll worth大廈。</p&g

85、t;<p>　　房屋高度與高寬比的不斷增加也帶來了許多的問題。為了控制道路的阻塞，要對建筑的縮進設計進行限定。側向支撐的設置也是其中一項技術問題，例如，埃非爾鐵塔所采用的對角支撐體系對于要靠太陽光來照明的辦公大廈就不實用了。而只有考慮到具體的單獨梁與單獨柱的抗彎能力以及梁柱相交處的剛度的框架設計才是可靠的。隨著現(xiàn)代內部采光體系的不斷發(fā)展，抵抗風荷載的對角支撐又重新被利用起來了。芝加哥的John Hancock 中心就是一個

86、很顯著的例子。外部的對角支撐成為此結構立面的一個很顯眼的部分。</p><p>　　第一次世界大戰(zhàn)暫時中斷了所謂摩天大廈（當時這個詞并沒有確定）的蓬勃發(fā)展，但是二十世紀二十年代又恢復了這一趨勢。1931年建造的帝國大廈把詞潮流推向了頂峰。102層高1250英尺（381米）的帝國大廈在后來的40年一直保持著世界最高的地位。它的建造速度充分證明了這種新的結構形式已經(jīng)被當時的技術所掌握。次項工程所需要的梁是由Bayon

87、ne海灣對岸的軍械庫所提供的。是由用精密儀器控制的駁船和卡車負責運輸?shù)?。由九架起重機將這些梁提升到指定的位置。由工業(yè)軌道裝置把鋼材和其他材料移到每一層上去。先是螺栓連接緊接著鉚釘連接，最后是裝修，整個工程的最終完成只用了一年零45天。</p><p>　　二十世紀三十年代席卷全世界的大蕭條以及第而次世界大戰(zhàn)使鋼結構的發(fā)展又一次受到了阻礙。但是與此同時，焊接代替了鉚釘連接則是一個很重要的發(fā)展。</p>

88、<p>　　十九世紀末，利用焊接把各個鋼零件相連接已取得了很好的成績，并在第一次世界大戰(zhàn)中被運用于救生船的修理。但直到第二次世界大戰(zhàn)后才用于建筑結構中。同時在連接領域中又一進步就是高強螺栓代替了鉚釘。</p><p>　　二戰(zhàn)結束后，歐洲，美國，日本等國都擴大了對在不定應力（包括超過屈服點的情況）作用下各種結構鋼的性質的研究，并進行了更為精確、系統(tǒng)的分析。此后，許多國家采用了一些更為自由靈活的設計規(guī)范