土木工程专业英语 段兵延.docVIP

Lesson 4 Tall BuildingAlthough there have been many advancements in building construction technology in general, spectacular achievements have been made in the design and construction of ultrahigh-rise buildings．虽然在建筑施工技术中，总的来说已经有了许多进步，但是在超高层建筑的设计和施工中也取得了惊人的成就。The early development of high-rise buildings began with structural steel framing．高层建筑的早期发展始于结构的钢框架。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．从那以后，钢筋混凝土和薄壳筒体体系就被竞相经济地用在了许多民用和商用结构中。The high-rise buildings ranging from 50 to 110 stories that are being built all over the United States are the result of innovations and development of new structural systems．美国各地正在修建的50～110层的高层建筑是新的结构体系改革和发展的结果。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．更大的高度需要增加柱和梁的尺寸来使建筑物的刚性更大，以便于它们在风荷载作用下不会倾斜到允许的范围之外。Excessive lateral sway may cause serious recurring damage to partitions, ceilings, and other architectural details．过分的水平倾斜将导致隔板、天花板和其他建筑物细部的严重的复发性破坏。In addition, excessive sway may cause discomfort to the occupants of the building because of their perception of such motion．此外，过分的倾斜还可能导致建筑物内部居住者的不适，因为他们感觉到了这种运动。Structural systems of reinforced concrete, as well as steel, take full advantage of the inherent potential stiffness of the total building and therefore do not require additional stiffening to limit the sway．钢筋混凝土和钢结构系统充分利用了整个建筑的固有的潜在的刚度，因此不需要额外的加强板来限制倾斜。In a steel structure, for example, the economy can be defined in terms of the total average quantity of steel per square foot of floor area of the building.比如，在钢结构中，可以根据建筑物的每平方英尺楼板面积所需要钢材的总平均数量来限定经济。Curve A in Fig.1 represents the average unit weight of a conventional frame with increasing numbers of stories．图1中的曲线A描绘的是传统框架随着增加的楼层数的平均单位重量。Curve B represents the average steel weight if the frame is protected from all la