【正文】 this system is in the twin structural steel towers of the 110story World Trade Center building in New York. Columndiagonal 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 interesting 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 40story building. Bundled tube. With the continuing need for larger and taller buildings, the framed tube or the columndiagonal truss tube may be used in a bundled form to create larger tube envelopes while maintaining high efficiency. The 110story 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 heights of the building, demonstrating the unlimited architectural possibilities of this latest structural concept. The Sears tower, at a height of 1450 ft(442m), is the world’s tallest building. Stressedskin tube system. The tube structural system was developed for improving the resistance to lateral forces (wind and earthquake) and the control of drift (lateral building movement ) in highrise building. The stressedskin tube takes the tube system a step further. The development of the stressedskin tube utilizes the fa231。 二十世紀(jì)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(jié)構(gòu)的發(fā)展又一次受到了阻礙 。 1931 年建造的帝國大廈把詞 潮流推向了頂峰。 房屋高度與高寬比的不斷增加也帶來了許多的問題。十九世紀(jì)的最后幾年，基本結(jié)構(gòu)形狀工字型鋼的厚度已經(jīng)達(dá)到 20 英寸（ 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(jié)，使得構(gòu)件具體符合要求的尺寸和強(qiáng)度。鑄鐵制的過梁支撐著窗洞口上方的砌體，同時也需要鑄鐵制的柱支撐著。在上個世紀(jì)中葉，沒有經(jīng)過任何特殊合金強(qiáng)化、硬化過的普通碳素鋼已經(jīng)被廣泛地使用了。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(shè)的工程師的喜愛。隨后， 1819 年角鋼問世， 1894 年第一個工字鋼被 建造出來作為巴黎火車站的頂梁。 發(fā)展歷史：早在 Bessemer 和 SiemensMarton(開放式爐 )工藝出現(xiàn)以前，鋼結(jié)構(gòu)就已經(jīng)有幾十年的歷史了。 鋼結(jié)構(gòu)與混凝土結(jié)構(gòu)的聯(lián)合體系也有所發(fā)展。這種結(jié)構(gòu)體系已被建造在匹茲堡洲的 One Mellon 銀行中心所運用。 薄殼筒體系統(tǒng)：這種筒體結(jié)構(gòu)系統(tǒng)的設(shè)計是為了增強(qiáng)超高層建筑抵抗側(cè)力的能力（風(fēng)荷載和地震荷載）以及建筑的抗側(cè)移能力。 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(gòu)件聯(lián)系在一起，形成一個共同工作的筒體結(jié)構(gòu)。鋼結(jié)構(gòu)中的 體系：鋼結(jié)構(gòu)的高層建筑的發(fā)展是幾種結(jié)構(gòu)體系創(chuàng)新的結(jié)果。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(jì)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。這 些創(chuàng)新的結(jié)構(gòu)已經(jīng)被廣泛地應(yīng)用于辦公大樓和公寓建筑中。這種高度的結(jié)構(gòu)體系首次被芝加哥的 John Hancock 中心大廈采用。薄殼筒體是筒體系統(tǒng)的又一大飛躍。 鋼筋混凝土中的各體系：雖然鋼結(jié)構(gòu)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(jié)構(gòu)體系的有力競爭對手。 Skidmore ,Owings 和 Merrill共同設(shè)計的混合體系就是一個好例子。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(jié)構(gòu)所用。此工字鋼長 英尺）（ 米）。 其中一個很好的例子就是 Eads 大橋（也被稱為路易斯洲大橋）（ 18671874）。 在 1889 年巴黎召開的世界博覽會上，金屬結(jié)構(gòu)表現(xiàn)出了在超高層建筑運用上的內(nèi)在潛力。實心砌體 的天井與界墻提供抵抗風(fēng)載的側(cè)向支撐。 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）。為了控制道路的阻塞，要對建筑的縮進(jìn)設(shè)計進(jìn)行限定。 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。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。ade of the building as a structural element which acts with the framed tube, thus providing an efficient way of resisting lateral loads in highrise buildings, and resulting in costeffective columnfree interior space with a high ratio of to gross floor area. Because of the contribution of the stressedskin fa231。 decade by decade this figure rose until in the 1960s it exceeded 700 pounds (320 kilograms) per foot. Coincident with the introduction of structural steel came the introduction of the Otis electric elevator in 1889. 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 286ft () Flatiron Building of 1902 was surpassed in 1904 by the 375ft (115m) Times Building ( renamed the Allied Chemical Building) , the 468ft (143m) City Investing Company Building in Wall Street, the 612ft (187m) Singer Building (1908), the 700ft (214m) Metropolitan Tower (1909) and, in 1913, the 780ft (232m) Woolworth Building. The rapid increase in height and the heighttowidth 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 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 columns strategically designed into the skeleton frame, together with a high degree of rigidity sought at the junction of the beams and columns. With today’s modern interior lighting systems, however, diagonal bracing