外文翻译-建筑中的结构设计及建筑材料

Structure in Design of ArchitectureAnd Structural Material We have and the architects must deal with the spatial aspect of activity, physical, and symbolic needs in such a way that overall performance integrity is assured. Hence, he or she well wants to think of evolving a building environment as a total system of interacting and space forming subsystems. Is represents a complex challenge, and to meet it the architect will need a hierarchic design process that provides at least three levels of feedback thinking: schematic, preliminary, and final.Such a hierarchy is necessary if he or she is to avoid being confused , at conceptual stages of design thinking ,by the myriad detail issues that can distract attention from more basic considerations .In fact , we can say that an architects ability to distinguish the more basic form the more detailed issues is essential to his success as a designer .The object of the schematic feed back level is to generate and evaluate overall site-plan, activity-interaction, and building-configuration options .To do so the architect must be able to focus on the interaction of the basic attributes of the site context, the spatial organization, and the symbolism as determinants of physical form. This means that ,in schematic terms ,the architect may first conceive and model a building design as an organizational abstraction of essential performance-space in teractions.Then he or she may explore the overall space-form implications of the abstraction. As an actual building configuration option begins to emerge, it will be modified to include consideration for basic site conditions.At the schematic stage, it would also be helpful if the designer could visualize his or her options for achieving overall structural integrity and consider the constructive feasibility and economic of his or her scheme .But this will require that the architect and/or a consultant be able to conceptualize total-system structural options in terms of elemental detail .Such overall thinking can be easily fed back to improve the space-form scheme.At the preliminary level, the architects emphasis will shift to the elaboration of his or her more promising schematic design options .Here the architects structural needs will shift to approximate design of specific subsystem options. At this stage the total structural scheme is developed to a middle level of specificity by focusing on identification and design of major subsystems to the extent that their key geometric, component, and interactive properties are established .Basic subsystem interaction and design conflicts can thus be identified and resolved in the context of total-system objectives. Consultants can play a significant part in this effort; these preliminary-level decisions may also result in feedback that calls for refinement or even major change in schematic concepts.When the designer and the client are satisfied with the feasibility of a design proposal at the preliminary level, it means that the basic problems of overall design are solved and details are not likely to produce major change .The focus shifts again ,and the design process moves into the final level .At this stage the emphasis will be on the detailed development of all subsystem specifics . Here the role of specialists from various fields, including structural engineering, is much larger, since all detail of the preliminary design must be worked out. Decisions made at this level may produce feedback into Level II that will result in changes. However, if Levels I and II are handled with insight, the relationship between the overall decisions, made at the schematic and preliminary levels, and the specifics of the final level should be such that gross redesign is not in question, Rather, the entire process should be one of moving in an evolutionary fashion from creation and refinement (or modification) of the more general properties of a total-system design concept, to the fleshing out of requisite elements and details.To summarize: At Level I, the architect must first establish, in conceptual terms, the overall space-form feasibility of basic schematic options. At this stage, collaboration with specialists can be helpful, but only if in the form of overall thinking. At Level II, the architect must be able to identify the major subsystem requirements implied by the scheme and substantial their interactive feasibility by approximating key component properties .That is, the properties of major subsystems need be worked out only in sufficient depth to very the inherent compatibility of their basic form-related and behavioral interaction . This will mean a somewhat more specific form of collaboration with specialists then that in level I .At level III ,the architect and the specific form of collaboration with specialists then that providing for all of the elemental design specifics required to produce biddable construction documents .Of course this success comes from the development of the Structural Material.The principal construction materials of earlier times were wood and masonry brick, stone, or tile, and similar materials. The courses or layers were bound together with mortar or bitumen, a tar like substance, or some other binding agent. The Greeks and Romans sometimes used iron rods or claps to strengthen their building. The columns of the Parthenon in Athens, for example, have holes drilled in them for iron bars that have now rusted away. The Romans also used a natural cement called puzzling, made from volcanic ash, that became as hard as stone under water.Both steel and cement, the two most important construction materials of modern times, were introduced in the nineteenth century. Steel, basically an alloy of iron and a small amount of carbon had been made up to that time by a laborious process that restricted it to such special uses as sword blades. After the invention of the Bessemer process in 1856, steel was available in large quantities at low prices. The enormous advantage of steel is its tensile force which, as we have seen, tends to pull apart many materials. New alloys have further, which is a tendency for it to weaken as a result of continual changes in stress.Modern cement, called Portland cement, was invented in 1824. It is a mixture of limestone and clay, which is heated and then ground into a power. It is mixed at or near the construction site with sand, aggregate small stones, crushed rock, or gravel, and water to make concrete. Different proportions of the ingredients produce concrete with different strength and weight. Concrete is very versatile; it can be poured, pumped, or even sprayed into all kinds of shapes. And whereas steel has great tensile strength, concrete has great strength under compression. Thus, the two substances complement each other.They also complement each other in another way: they have almost the same rate of contraction and expansion. They therefore can work together in situations where both compression and tension are factors. Steel rods are embedded in concrete to make reinforced concrete in concrete beams or structures where tensions will develop. Concrete and steel also form such a strong bond the force that unites them that the steel cannot slip within the concrete. Still another advantage is that steel does not rust in concrete. Acid corrodes steel, whereas concrete has an alkaline chemical reaction, the opposite of acid.The adoption of structural steel and reinforced concrete caused major changes in traditional construction practices. It was no longer necessary to use thick walls of stone or brick for multistory buildings, and it became much simpler to build fire-resistant floors. Both these changes served to reduce the cost of construction. It also became possible to erect buildings with greater heights and longer spans.Since the weight of modern structures is carried by the steel or concrete frame, the walls do not support the building. They have become curtain walls, which keep out the weather and let in light. In the earlier steel or concrete frame building, the curtain walls were generally made of masonry; they had the solid look of bearing walls. Today, however, curtain walls are often made of lightweight materials such as glass, aluminum, or plastic, in various combinations.Another advance in steel construction is the method of fastening together the beams. For many years the standard method was riveting. A rivet is a bolt with a head that looks like a blunt screw without threads. It is heated, placed in holes through the pieces of steel, and a second head is formed at the other end by hammering it to hold it in place. Riveting has now largely been replaced by welding, the joining together of pieces of steel by melting a steel material between them under high heat.Priestesss concrete is an improved form of reinforcement. Steel rods are bent into the shapes to give them the necessary degree of tensile strengths. They are then used to priestess concrete, usually by one of two different methods. The first is to leave channels in a concrete beam that correspond to the shapes of the steel rods. When the rods are run through the channels, they are then bonded to the concrete by filling the channels with grout, a thin mortar or binding agent. In the other (and more common) method, the priestesses steel rods are placed in the lower part of a form that corresponds to the shape of the finished structure, and the concrete is poured around them. Priestesss concrete uses less steel and less concrete. Because it is a highly desirable material.Progressed concrete has made it possible to develop buildings with unusual shapes, like some of the modern, sports arenas, with large spaces unbroken by any obstructing supports. The uses for this relatively new structural method are constantly being developed.中文译文：建筑中的结构设计及建筑材料建筑师必须从一种全局的角度出发去处理建筑设计中应该考虑到的实用活动，物质及象征性的需求。因此，他或他试图将有相互有关的空间形式分体系组成的总体系形成一个建筑环境。这是一种复杂的挑战，为适应这一挑战，建筑师需要有一个分阶段的设计过程，其至少要分三个“反馈”考虑阶段：方案阶段，初步设计阶段和施工图设计阶段。这样的分阶段涉及是必需的，它可使设计者避免受很多细节的困惑，而这些细节往往会干扰设计者的基本思路。实际上，我们可以说一个成功的建筑设计师应该具备一种从很多细节中分辨出更为基本的内容的能力。概念构思阶段的任务时提出和斟酌全局场地规划，活动相互作用及房屋形式方案。为实现这些，建筑师必须注意场地各部分的基本使用，空间组织，并应用象征手法确定其具体形式。这就要求建筑师首先按照基本功能和空间关系对一项建筑设计首先构思并模拟出一个抽象的建筑物，然后再对这一抽象的总体空间进行深入探究。在开始勾画具体的建筑形似时，应考虑基本的场所跳进加以修改。在方案阶段，如果设计者能够形象的预见所作方案的结构整体性，并要考虑施工阶段可行性及经济性，那将是非常有帮助的。这就要求建筑师或者过问工程是能够从主要分体系之间的关系而不是从构建细节去构思总体结构方案。这种能够易于反馈以改进空间形式方案。在初步设计阶段，建筑师的重点工作应是详细化可能成为最终方案的设计，这是建筑师对结构的要求业转移到做分体系具体方案的粗略设计上。在这一阶段应该完成对结构布置的中等程度的确定，重点论证和设计主要分体系已确定它们的主要几何尺寸，构件和相互关系。这样就可以依据全局设计方案，确定并解决各分体系的相互影响以及设计难题。顾问工程师在这一过程中作用重大，但各细部的考虑还留有选择余地。当然，这些初步设计阶段所作的决定仍可以反馈回取使方案概念进一步改善，或甚至可能有重大变化。当设计者和顾问工程师对初始阶段设计方案的可行性满意时，就意味着全部设计的基本问题已经解决，不会再因细节问题而发生大的变化。这是工作重点将再次转移，进入细部设计。在这一阶段将重点完善各分体系的细节设计。此时包括结构工程在内的各个领域的专家的作用将十分突出，应为所有施工的细节都必须设计出来。这一阶段的决定，可能会反馈到第二阶段并导致一些变化。如果第一阶段和第二阶段的设计做的深入，那么在最初两个阶段所得到的总体结论和最后阶段的细节的重新设计不再是问题。当然，整个实际过程应该是逐步发展的过程，从创造和细化（改进）总体设计概念直到做出精确的结构设计和细部构造。综上所述：在第一阶段，建筑师必须首先用概念的方式来确定基本方案的全部空间形式的可行性。在第一阶段，专业人员的合作是有意义的，但仅限于行程总的构思方面；在第二阶段，建筑师应该能够用图形来确定各分体系的需求，并且通过估计关键构件的性能来证明其相互作用的可行性。也就是说，主要分体系的性能只须做到一定深度，需要验证他们的基本形式和相互关系是协调一致的。这需要与工程师进行更加详细与明确的合作；在第三阶段，建筑师和专业人员必须继续合作完成所有构件的设计细节，并制定良好的施工文件。当然，这些设计的成功来源于建筑材料的发展与革新。早期的建筑材料主要是木材和砌块,如砖块、石材或瓦片及其它类似的材料。砖和砖之间是由砂浆或者焦油状的沥青或其它粘合物粘结在一起。希腊人和罗马人有时利用铁棒或夹钳来加固他们的建筑。例如,在雅典的帕台农神庙的柱子,就是由在水中也能变得如石材般坚硬的火山灰建成的。钢材和水泥现代最重要的两种建筑材料,在19世纪得到