外文翻译---- 高层建筑设计标准.docx

译文： 高层建筑设计标准 高层建筑是都市化的结果就如自从美国19世纪后期第一栋摩天大楼被建造出来以后。工业化社会吸引了更多的人来到城市，因此需要更多的空间被用来工作和居住。高层建筑，需要两个基本的技术要素。首先，必须找到一个建造高层建筑的经济的方法；二，必须提供一个可靠的经济的运输方法，使人们垂直通过建筑。尽管奥蒂斯电梯在十九世纪后期为垂直运输系统提供了合乎逻辑的解决方法，但结构仍然是一个非常重要的威慑力量对于修建非常高的建筑物来说。具有开拓精神的芝加哥建筑学派运用梁柱框架结构，但仍需要很高的”保费高度”对于高于20层的建筑物的来说。因此，在20世纪20年代建成的建筑大多低于这个高度。一个伟大的进步在1930发生，当时帝国大厦的建造或多或少的运用到了传统的施工方法。这是没有任何经济突破的事例。从这一时候开始的整个30年代几乎所有的高层建筑都被抑制进行了。二战后的社会经济需要，促使美国开辟建造更高的办公楼和公寓楼。但是，这些建筑不能再用和早期建筑一样的方式和比例来设计了，仅仅是因为这个整洁无柱的空间概念，建筑内部气候的控制和交通流线的概念都发生了巨大的变化。建筑的所有的这些变化态度带来了时代的新建筑。新的需求和挑战被用来创造城市的环境。在过去的几年里，研究建筑材料如钢筋混凝土和钢结构方面已取得了很大的进步和开拓的视野，能更有效地利用这些材料。但结构工程师和建筑师也遇到了挑战，即找到高效和经济的新的结构系统来解决不同范围和高度的建筑物要超过100层的方法。因此，在选择高层建筑结构体系时，要选择比它以前更复杂的结构。使结构系统的方法在总建筑设计中得到应用。在选择高层建筑结构体系的过程中大部分取决于标准而不是结构。不了解所有这些重要的标准，会使结构工程师在他的工作中感到沮丧。设计一个建筑的过程中涉及到多个学科，由于结构是总规划中的一个组成部分，一个创新概念的成功通过将会使工程师有一个很困难的时期去接受它如果他们不了解这些标准的话，以下是一个简短的讨论关于这些设计标准。1. 环境规划的思考。在任何环境中增加了一个高层建筑肯定会对其交通系统造成一定的影响，以及整个街区的人流量。因此，高层建筑工程必须解决行人、汽车和其他交通流线，并解决总平面上的空间需求。而开放式广场可能是一个可行的解决方案对于在一定的气候和规划条件下，但当天气条件为冬季或夏季的时候它则可能不是一个合理的解决方案。在这种情况下，交替打开的广场必须被视为一个好的整体解决方案，并且结构系统必须要能够支撑它。2. 塔楼的总体比例。建筑和周围的环境和其他现有建筑及广场的关系可支配塔楼自身的比例。当然，一个明显的扁平塔楼将会有一个更高的高宽比，这通常意味着更多的横向摆动。增加高宽比通常意味着将增加为高度引起而需减少横向摆动所造成的额外所需材料的费用，以及增加抗倾覆能力。因此，这对于高层建筑将是一个重要的要求，即必须找到效率较高的替代结构方案，尽管这种系统相对较标准的建筑形式可能会提高制造与施工成本。3. 允许的楼面面积的比率。建筑在城市地区的建造一般被规划控制着。不幸的是规划在大多数情况下是出于对政治和经济的考虑。规划通常会允许在人口密集的城市中心可以建立的任何特定的网络的最大数量的平方英尺，这成为一个重要的考虑，特别是在高土地成本地区，可以建立在一个给定的一块土地得到更多的经济回报潜力。因此，在自由企业制度下，有充分理由相信投资者想建立填充允许容积率，这将意味着更高的建筑比其他被认为是符合环境的，在这里就挑战建筑师和工程师使用不同的结构系统，提供可行的替代品，提出更合理、更令人满意的解决方案供选择。4. 内部空间标准。仅仅几年前，列间距20英尺，已被接受作为无法克服一个结构限制，已被广泛接受。较新的结构系统给建筑师和开发商创造更大的无柱空间的办公室，以及住宅楼宇的选择。在办公楼为例，现在35英尺的空间间距是通常被认为最小的，当然大多数开发商是不会介意的，如果他们能够得到一个60英尺的空间跨度的话。明确核心柱和外墙之间的跨度。正是出于这种设计考虑，导致发展一个不需要列在任何核心和外墙之间的空间结构系统。作为酒店和公寓楼这倒是常见的情况，即从走廊外墙的最大距离通常不超过30英尺，因为每个房间通常是需要有一个外部接触。这种规划要求公寓和旅馆建筑宽度不能超过70至90英尺的。虽然大量的公寓楼已建成，但这些建筑的宽度仍远远低于将用于高效的办公楼的建筑，这种类型的要求，当然，马上就可能会有更高的高宽比的住宅楼，和由此产生的结构体系选型的办公楼。5. 气候因素。气候因素有时在选择结构系统时会发挥强有力的作用。在极冷的冬天气候总的趋势是提供较大的，透明的窗口，或许是因为人们更需要一个窗口去寻找和尽可能地享受自然。另一方面，在炎热的热带气候地区，减少玻璃的使用和用更坚实砖石或混凝土做表面是更经济的方法。这正好是占用较小的需要来看看外面。结构系统的内部使用大型外承重墙，因此，该结构往往在这样的气候条件下受到欢迎。6. 结构材料的考虑。对于一个系统的选择，严格取决于当地的相对经济的各种结构材料。正是由于这个原因，同时，在一个地区混凝土结构系统可能是经济，而在国家的另一地区钢结构系统有可能成为更经济的。当然有些时候，两者相结合的材料在同一建筑的造成中可能是最佳的设计。7. 基础的思考。高层建筑需要一个稳定的基础。如果岩石是直接有效地接近水平面，那么结构体系的选择或材料的选择将不会受到影响。然而，在许多地区，例如，浮基是唯一的支撑建筑的方式，结构的总重量将变得非常重要，因为它控制了总开挖深度。在这种情况下，轻重量的建设将是明显的结构选择。这可能导致对于一个钢结构框架，或轻质混凝土施工，或一个复合系统的选择取决于当地的物质经济。8. 建造时间。虽然一个项目的建造时间似乎是一个明显的因素在选择建筑的类型时，但它常常被忽视的，在对结构系统的估计时对建设总工期没有任何考虑。这可能影响不大，临时融资在建设中不是一个关键项目。但是，在大多数的项目投资中，这都不能被忽视。如果建设一个1500000平方英尺的建筑需要6个月以上的时间，在另一个竞争性的体系结构，这可能意味着相当于损失1500000美元的总建筑成本。因此，在选择结构系统，这一标准应被考虑，只有当开发商有特殊要求时才能被排除。原文：design criteria for tall building the construction of tall buildings is the result of urbanization as seen in america since the late nineteenth century when the fist skyscrapers were built. the industrialized society attracts more people to the cities, requiring more space for offices as well as for habitation. tall buildings, however, require two basic technical ingredients. first, economic method of building a tall building must be found and second, a reliable and economic method of transporting people vertically through the building must be available. even though the otis elevator in the late 19th century provided the logical answer to vertical transportation, the structure still remained a very significant deterrent to building very tall buildings. the pioneering chicago school of architecture refined the use of beam-column frames, but still required high “premium for height” for buildings taller than say 20 stories. as a result, buildings built up to 1920s were mostly below stories. a heroic step was taken in 1930 when the empire state building was built with more or less conventional method of construction. this was no example of any economic breakthrough. from the time of depression in the30s hardly any high rise construction was undertaken. after world war ii the socioeconomic needs in the u.s. opened the way for more taller office and apartment buildings. but , these buildings could no longer be designed in the same manner and proportion as the earlier buildings, simply because the concept of uncluttered column-free space, the concept of climate control and communication in the buildings have drastically changed. all these changes in attitudes brought the era of a new architecture. the new demand and challenge was to create total urban environments.within the last few years, research on building materials such as reinforced concrete and structural steel have made great strides and opened horizons for more efficient use of these materials. the structural engineers and architects also have met the challenge to find efficient and economical new structural systems for various ranges and heights of buildings going all the way to well over 100stories. consequently, the process of selecting a structural system for a tall building has become more complicated than it ever was. structural system approach used for the total design of a building.the process of choosing the structural system for a tall building depends on many criteria which are not always structural. without the understanding of all of these significant criteria, the structural engineer would feel frustrated in his efforts. the process of designing a building is multi-discipline, and since structure is an integral part of the total scheme, the successful adoption of an innovation in concept will have a much harder time of for acceptance if the engineer does not have an understanding of these criteria, the following is a brief discussion of these design criteria.1. environmental planning consideration. in any environment the addition of a tall building will certainly influence the operation of the traffic system, as well as the flow of people in the entire neighborhood. therefore, a tall building project must be resolved in terms of pedestrian, auto and other traffic, and also resolve the overall need for space at the ground level. while an open plaza may be a viable solution under certain climatic and planning conditions, it may not be a reasonable solution where weather conditions are extreme either for winter or for summer. in such cases alternate to open plazas must be considered as a pan of the total solution, and the structural system must respond to it.2. the overall proportions of the tower. the relationship of the building to the surrounding environment and other existing buildings and plazas may dictate the proportions of the tower itself. it is, of course, obvious that a flat narrow tower will have a higher height-to-width ratio, which normally would mean more lateral sway. the increase in height-to-width ratio will generally mean increase in premium for height caused by additional material required to reduce lateral sway, as well as to increase resistance to overturning. therefore, where slender buildings is an important requirement it is essential to find alternate structural solutions of higher efficiency even though such a system may increase fabrication and construction costs relative to more standard forms of construction.3. permissible floor area ratio. the construction of buildings in the city area is generally controlled by zoning. zoning, in most cases, unfortunately, is the product of political and economic consideration. zoning would normally allow a maximum number of square feet that can be built at any given site in dense urban centers this becomes a critical consideration, particularly because in terms of high land cost the more area that can be built on a given piece of land, the more the potential for economic return. under the free enterprise system, therefore, there is every reason to believe that investors would like to build the fill allowable floor area ratio, which will then mean a taller building than otherwise considered consistent with the environment, here again, the challenge to the architects and engineers is to provide viable alternatives using different structural systems from which a more rational and a more satisfying solution can be chosen.4. inner space criteria. only a few years back, column spacing of 20ft. was accepted as a structural limitation that could not be overcome. newer structural systems have given the architect and developers the choice to create larger column free spaces in the office, as well as residential buildings. in the office buildings for instance, 35ft.clear spacing is now normally considered the minimum and most developers would not mind if they can get a 60ft. clear span between the core and the exterior walls. it is this kind of design consideration that has led to the development of a number of structural systems which do not require any column in the space between the core and the exterior walls. for apartments and hotel buildings the reverse is normally the case, that is, the maximum distance from the corridor to the outer wall does not normally exceed 30ft., because every room is generally required to have an exterior exposure. this kind of planning requirement means that apartment and hotel buildings cannot be wider than between 70 to 90ft. although wider apartment buildings have been built, the width of such buildings are still far less than what would be used for efficient office buildings, this type of requirement, of course, immediately means the possibility of a higher height-to-width ratio for residential buildings, and consequent selection of structural systems different than for office building.5. climatic considerations. climatic considerations sometimes play a strong part in choosing the structural system. for extremely cold winter climate the general tendency is to provide larger, clear windows, perhaps because there is a greater need for the occupant to look out and enjoy the nature as much as possible. on the other hand, in hot tropical climate it is more economical to have less glass and more solid masonry or concrete surface. this coincides with lesser need for the occupants to look outside. structural systems which inherently use large exterior bearing walls are, therefore, quite often welcome in such climatic conditions.6. structural material considerations. the selection of a system depends strictly on the local relative economies between the various structural materials. it is because of this reason that while, in one area a concrete structural system may be economical, in another area of the country a structural steel system may become more economical. sometimes, of course, a combination of both materials in the same building may result in the optimum design.7. foundation considerations. tall buildings require a stable foundation. where rock is directly available near the ground level, the choice of structural system or material is not affected. however, in many areas where, for instance, floa