【正文】 htweight concrete building ( the 52story One Shell Plaza Building in Houston) for the unit price of a traditional shear wall structure of only 35 stories. Systems bining both concrete and steel have also been developed, an examle of which is the posite system developed by skidmore, Owings amp。the simplicity of their design proved highly practical even in the absence of sophisticated analysis techniques. Throughout the first third of the century, ordinary carbon steel, without any special alloy strengthening or hardening, was universally used. The possibilities inherent in metal construction for highrise building was demonstrated to the world by the Paris Exposition of which AlexandreGustave Eiffel, a leading French bridge engineer, erected an openwork metal tower 300m (984 ft) high. Not only was the heightmore than double that of the Great Pyramidremarkable, but the speed of erection and low cost were even more so, a small crew pleted the work in a few months. The first skyscrapers. Meantime, in the United States another important development was taking place. In 188485 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 Bessemer 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 against wind loading. Within a decade the same type of construction had been used in more than 30 office buildings in Chicago and New York. Steel played a larger and larger role in these , with riveted connections for beams and columns, sometimes strengthened for wind bracing by overlaying gusset plates at the junction of vertical and horizontal members. Light masonry curtain walls, supported at each floor level, replaced the old heavy masonry curtain walls, supported at each floor level , replaced the old heavy masonry. 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 basic structural shapesI beams up to 20 in. ( ) in depth and Z and T shapes of lesser proportions were readily available, to bine with plates of several widths and thicknesses to make efficient members of any required size and strength. In 1885 the heaviest structural shape produced through hotrolling weighed less than 100 pounds (45 kilograms) per foot。 50 層到 100 層的建筑被定義為超高層建筑。在這座大樓中，外柱 的柱距為 英尺（ 米）。在新奧爾良建造的 52層的獨(dú)殼廣場(chǎng)大廈就是運(yùn)用了這種體系。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(jià)隨高度而變化的情況。這種特殊的結(jié)構(gòu)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。這些獨(dú)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(jié)構(gòu)觀念的建筑風(fēng)格自由化的潛能。托梁周圍的厚度也可適當(dāng)?shù)臏p小。長(zhǎng)久以來(lái)一直用木材制作的三角桁架也換成鐵制的了。在金屬結(jié)構(gòu)的發(fā)展歷史中，有兩個(gè)標(biāo)志性事件：首先是從木橋發(fā)展而來(lái)的格構(gòu)梁由木制轉(zhuǎn)化為鐵制；其次是鍛鐵制的受拉構(gòu)件與鑄鐵制的受壓構(gòu)件受熱后通過(guò)鉚釘連接工藝的發(fā)展。 1907年 Quebec懸索大橋的偶然破壞揭露了二十世紀(jì)初期由于缺乏足夠 的理論知識(shí)，甚至是缺乏足夠的理論研究的基礎(chǔ)知識(shí)，而導(dǎo)致在應(yīng)力分析方面出現(xiàn)了很多的不足。18841885年，芝加哥的工程師 Le Baron Jennny設(shè)計(jì)了家庭保險(xiǎn)公司大廈。有時(shí)為了抵抗風(fēng)荷載還是在豎向構(gòu)件和橫向構(gòu)件的連接點(diǎn)出貼覆上節(jié)點(diǎn)板來(lái)加固結(jié)構(gòu)。 1902 年在紐約建造的高 286英寸（ ）的 Flatiron大廈不斷地被后來(lái)的建筑所超越。芝加哥的 John Hancock 中心就是一個(gè)很顯著的例子。由九架起重機(jī)將這些梁提升到指定的位置。 二戰(zhàn)結(jié)束后，歐洲，美國(guó)，日本等國(guó)都擴(kuò)大了對(duì)在不定應(yīng)力（包括超過(guò)屈 服點(diǎn)的情況）作用下各種結(jié)構(gòu)鋼的性質(zhì)的研究，并進(jìn)行了更為精確、系統(tǒng)的分析。但直到第二次世界大戰(zhàn)后才用于建筑結(jié)構(gòu)中。次項(xiàng)工程所需要的梁是由 Bayonne海灣對(duì)岸的軍械庫(kù)所提供的。而只有考慮到具體的單獨(dú)梁與單獨(dú)柱的抗彎能力以及梁柱相交處的剛度的框架設(shè)計(jì)才是可靠的。 緊隨著鋼結(jié)構(gòu)的發(fā)展， 1988 年第一部電梯問(wèn)世了。鋼材在這些結(jié)構(gòu)中起了非常大的作用。無(wú)論是它的高度（比著名的金字塔的兩倍還高），架設(shè)的速度 人數(shù) 不多的工作人員僅用幾個(gè)月的時(shí)間就完成了整個(gè)工程任務(wù)，還是很低的工程造價(jià)都使它脫穎而出。英國(guó)的Firth of Forth懸索橋設(shè)有管件支撐，直徑大約為 12英尺（ ），長(zhǎng)度為 350英尺（ 107）米。說(shuō)當(dāng)時(shí)他已有這樣的骨架結(jié)構(gòu)構(gòu)思：用比較細(xì)的鐵梁作為玻璃幕墻的骨架。這座大橋以及后來(lái)的鐵橋設(shè)計(jì)再加上 蒸汽鍋爐、鐵船身的設(shè)計(jì)都刺激了建筑安裝設(shè)計(jì)以及連接工藝的發(fā)展。這樣以來(lái)使得結(jié)構(gòu)既輕巧又經(jīng)濟(jì)。筒體結(jié)構(gòu)和斜撐桁架筒體被設(shè)計(jì)成捆束狀以形成更大的筒體來(lái)保持建筑物的高效能。 框架筒結(jié)構(gòu)： 如果所有的構(gòu)件都用某種方式互相聯(lián)系在一起，整個(gè)建筑就像是從地面發(fā)射出的一個(gè)空心筒體或是一個(gè)剛性盒子一樣。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。 Skidmore ,Owings 和 Merrill 共同設(shè)計(jì)的混合體系就是一個(gè)好例子。 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?？?，無(wú)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(jìng)爭(zhēng)對(duì)手。 最初的高層建筑設(shè)計(jì)是從鋼結(jié)構(gòu)的設(shè)計(jì)開(kāi)始的。 first, the use of latticed girder, which are small trusses, a form first developed in timber bridges and other structures and translated into metal by Paxton 。Merril in which an exterior closely spaced framed tube in concrete envelops an interior steel framing, thereby bining the advantages of both reinforced concrete and structural steel systems. The 52story One Shell Square Building in New Orleans is based on this sy