1、 第五部分 英文论文翻译 Talling building and Steel construction Although there have been many advancements in building construction technology in general. Spectacular archievements have been made in the design and construction of ultrahigh-rise buildings. The early development of high-rise buildings began with
2、 structural steel framing.Reinforced concrete and stressed-skin 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 over the United Stat
3、es are the result of innovations and development of new structual systems. Greater height entails increased column and beam sizes to make buildings more rigid so that under wind load they will not sway beyond an acceptable limit.Excessive lateral sway may cause serious recurring damage to partitions
4、,ceilings.and other architectural details. In addition,excessive sway may cause discomfort to the occupants 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 of the total building and
5、 therefore require additional stiffening to limit the sway. In a steel structure,forexample,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 incre
6、asing 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 traditional column-and-beam frame.Structural engineers have developed structural
7、 systems with a view to eliminating this premium. Systems in steel. Tall buildings in steel developed as a result of several types of structural innovations. The innovations have been applied to the construction of both office and apartment buildings. Frame with rigid belt trusses. In order to tie t
8、he exterior columns of a frame structure to the interior vertical trusses,a system of rigid belt trusses at 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. Framed tube. The maximum efficiency of the total s
9、tructure 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 box in projecting out of the ground. This particular structural system was
10、probably used for the first time in the 43-story reinforced concrete DeWitt Chestnut Apartment Building in Chicago. The most significant use of this system is in the twin structural steel towers of the 110-story World Trade Center building in New York Column-diagonal truss tube. The exterior columns
11、 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,
12、 using as much steel as is normally needed for a traditional 40-story building. 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 envelopes while maintaining high efficiency. T
13、he 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 heights of the building, demonstrating the unlimited architectural possibilities of this latest structural concept. The
14、Sears tower, at a height of 1450 ft(442m), is the worlds tallest building. Stressed-skin 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 high-rise building. The stresse
15、d-skin tube takes the tube system a step further. The development of the stressed-skin tube 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 resulting in cost-effective
16、column-free interior space with a high ratio of net to gross floor area. Because of the 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,minimizin
17、g the use 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 structural system has been used on the 54-story One Mellon Bank Center in Pittb
18、urgh. Systems in concrete.While tall buildings constructed of steel had an early start, development of tall buildings of reinforced concrete progressed at a fast enough rate to provide a competitive chanllenge to structural steel systems for both office and apartment buildings. Framed tube. As discu
19、ssed above, the first framed tube concept for tall buildings 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) flat-plate concrete slabs.
20、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 of an outer framed tube of very closely spaced columns and an interior rigid shear wall tube enclosing the central service area.
21、 The system (Fig .2), known as the tube-in-tube system , made it possible to design the worlds present tallest (714ft or 218m)lightweight concrete building ( the 52-story One Shell Plaza Building in Houston) for the unit price of a traditional shear wall structure of only 35 stories. Systems combini
22、ng both concrete and steel have also been developed, an examle of which is 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 and struc
23、tural steel systems. The 52-story One Shell Square Building in New Orleans is based on this system. Steel construction refers to a broad range of building construction in which steel plays the leading role. Most steel construction consists of large-scale buildings or engineering works, with the stee
24、l generally in the form of beams, girders, bars, plates, and other members shaped through the hot-rolled process. 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 pr
25、oducers in the 1970s. Early 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 sufficient for structure use. Many of problems of steel
26、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 in 1777. This and subsequent iron bridge work, in addition to the construction of steam boilers and iron ship hulls , spurred the dev
27、elopment of techniques for fabricating, designing, and jioning. The advantages of iron over masonry lay in the much smaller amounts of material required. The truss form, based on the resistance of the triangle to deformation, long used in timber, was translated effectively into iron, with cast iron
28、being used for compression members-i.e, those bearing the weight of direct loading-and wrought iron being used for tension members-i.e, those bearing the pull of suspended loading. The technique for passing iron, heated to the plastic state, between rolls to form flat and rounded bars, was developed
29、 as early as 1800；by 1819 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. Two years later Joseph Paxton of England built the Crystal Palace for the London Exposition of 1851. He is said to have conceived th
30、e idea of cage construction-using relatively slender iron beams as a skeleton for the glass walls of a large, open structure. Resistance to wind 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 developed in timber bridges and other structures and translated into metal by Paxton ； and second, the joining of wrought-iron tension members and cast-iron
