外文翻译---建筑中的结构设计及建筑材料

外文翻译---建筑中的结构设计及建筑材料

Structure in Design of Architecture

And 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 architect’s 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 architect’s emphasis will shift to the elaboration of his or her more promising schematic design options .Here the architect’s 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.

Prieste ss’s 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. Priestess’s concrete uses less steel and less concrete. Because it is a highly desirable material.

Because foundation vertical to even to subside or horizontal direction displacement, make the structure produce the additional stress, go beyond resisting the ability of drawing of concrete structure, cause the structure to fracture. The even main reason that subside of the foundation is as follows, 1, Reconnoitres the precision and is not enough for , test the materials inaccuratly in geology. Designing, constructing without fully grasping the geological situation, this is the main reason that cause the ground not to subside evenly . Such as hills area or bridge, district of mountain ridge,, hole interval to be too far when reconnoitring, and ground rise and fall big the rock, reconnoitring the report can't fully reflect the real geological situation . 2, The geological difference of the ground is too large. Building it in the bridge of the valley of the ditch of mountain area, geology of the stream place and place on the hillside change larger, even there are weak grounds in the stream, because the soil of the ground does not causes and does not subside evenly with the compressing. 3, The structure loads the difference too big. Under the unanimous terms, when every foundation too heavy to load difference in geological situation, may cause evenly to subside, for example high to fill out soil case shape in the middle part of the culvert than to is it take heavy to load both sides, to subside soon heavy than both sides middle part, case is it might fracture to contain 4, The difference of basic type of structure is great. Unite it in the bridge the samly , mix and use and does not expand the foundation and a foundation with the foundation, or adopt a foundation when a foot-path or a long difference is great at the same time , or adopt the foundation of expanding when basis elevation is widely different at the same time , may cause the ground not to subside evenly too 5, Foundation built by stages. In the newly-built bridge near the foundation of original bridge, if the half a bridge about expressway built by stages, the newly-built bridge loads or the foundation causes the soil of the ground to consolidate again while dealing with, may cause and subside the foundation of original bridge greatly 6, The ground is frozen bloatedly. The ground soil of higher moisture content on terms that lower than zero degree expands because of being icy; Once temperature goes up , the frozen soil is melted, the setting of ground. So the ground is icy or melts causes and does not subside evenly . 7, Bridge foundation put on body, cave with stalactites and stalagmites, activity fault,etc. of coming down at the bad geology, may cause and does not subside evenly . 8, After the bridge is built up , the condition change of original ground . After most natural grounds and artificial grounds are soaked with water, especially usually fill out such soil of special ground as the soil , loess , expanding in the land ,etc., soil body intensity meet water drop, compress out of shape to strengthen. In the soft soil ground , season

causes the water table to drop to draw water or arid artificially, the ground soil layer consolidates and sinks again, reduce the buoyancy on the foundation at the same time , shouldering the obstruction of rubing to increase, the foundation is carried on one's shoulder or back and strengthened .Some bridge foundation is it put too shallow to bury, erode , is it dig to wash flood, the foundation might be moved. Ground load change of terms, bridge nearby is it is it abolish square , grit ,etc. in a large amount to put to pile with cave in , landslide ,etc. reason for instance, it is out of shape that the bridge location range soil layer may be compressed again. So, the condition of original ground change while using may cause and does not subside evenly Produce the structure thing of horizontal thrust to arched bridge ,etc., it is the main reason that horizontal displacement crack emerges to destroy the original geological condition when to that it is unreasonable to grasp incompletely , design and construct in the geological situation.

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.

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世纪得到了推广。钢材(从根本上说,是以铁为主要成分并含有少量碳元素的合金),直到出现能够限制其特殊用途(如制造刀刃)的费劳力的铸造方法,才被铸造出来。在1856年贝塞麦炼钢法出现之后,钢材就以较低的价格大量供应。钢材最大的优点就是它的抗拉强度非常高,这也就是说,当它在我们已知的能拉断许多材料的一定拉力作用下,钢材不会丧失它的强度。新的合金元素的加入,大大增加了钢材的强度,并消除的它的一些缺点。例如,钢材在应力不断变化时所表现出的疲劳强度有所见减小的倾向。

现代的水泥(也叫波特兰水泥),发明于1824年。它是一种由石灰石和粘土加热后碾成粉末的混合物。它是在施工现场与砂子、骨料(小石块、碎石、砾石)及水,拌制成混凝土。各成分含量的不同, 拌制出的混凝土强度和重量也不同。混凝土应用十分广泛,它可以浇筑、泵送甚至喷射成所有形状。而钢材有很高的抗拉强度和混凝土具有很高的抗压强度,因此,这两种材料相互弥补了各自的不足。

钢筋和混凝土也在以另一种方式互补,就是它们几乎有着相同的收缩率和膨胀率。因此它们可以在拉力与压力同时存在的条件下共同工作。混凝土中加入钢筋,可以制成钢筋混凝土梁或其它钢筋混凝土构件以抵抗出现的拉力。混凝土和钢筋之间形成一种使它们粘结在一起的粘结力,这个力使钢筋在混凝土中不会产生滑移。酸会腐蚀钢筋,而混凝土会产生与酸相反的碱性化学反应。

结构钢和混凝土的使用是传统的施工方式产生的主要变化。它使人们在建造多层建筑时,不再必须使用以石材或砖砌筑的厚墙了,并且也使建造一个防火地面变得简单多了。这些变化都有利于降低施工的费用,而且这使建造更高更大的结构变成可能。

现代建筑物的重量由钢或混凝土框架来承受,因此墙体不再做承重墙。它们已经变成能够抵挡风雨并进行采光的幕墙了。在早期的钢或混凝土框架建筑中,幕墙一般由砌块建成,这些砌块有着和承重墙一样坚实的外观。但是现在, 幕墙则一般由诸如玻璃、铝、塑料或各种混合材料等轻质材料建成的。

在钢材建造中的另一种优点是梁之间的连接方法。多年来,传统的连接方法是铆接。铆钉是一种有一头看起来像没有螺纹的圆头螺丝钉。在现场施工时,铆钉被加热,穿过刚片间的孔洞,在另一端靠锤击形成另一个头以使之固定就位。现在铆接大多已经被焊接取代,焊接是一种通过在高温下钢材使它们连接在一起的连接方式。

预应力混凝土是钢筋混凝土的一种改良方式。将钢筋弯成各种形状,使钢筋具有一定的拉应力。然后它们被用于预应力混凝土,这种施工方法有两种。一种方法是在混凝土中预留与钢筋形状相同的孔道,当钢筋穿过孔道后,通过向孔道灌注砂浆或粘结剂使钢筋和混凝土粘结在一起。另一种更常用的方法是将钢筋置于与成品构件外形相符的模板底部,然后在钢筋周围浇注混凝土。预应力混凝土用钢量和用混凝土量都比较少。由于它的这个显著的经济性, 预应力混凝土是一种非常理想的材料。由于基础竖向不均匀沉降或水平方向位移，使结构中产生附加应力，超出混凝土结构的抗拉能力，导致结构开裂。基础不均匀沉降的主要原因有： 1、地质勘察精度不够、试验资料不准。在没有充分掌握地质情况就设计、施工，这是造成地基不均匀沉降的主要原因。比如丘陵区或山岭区桥梁，勘察时钻孔间距太远，而地基岩面起伏又大，勘察报告不能充分反映实际地质情况。 2、地基地质差异太大。建造在山区沟谷的桥梁，河沟处的地质与山坡处变化较大，河沟中甚至存在软弱地基，地基土由于不同压缩性引起不均匀沉降。 3、结构荷载差异太大。在地质情况比较一致条件下，各部分基础荷载差异太大时，有可能引起不均匀沉降，例如高填土箱形涵洞中部比两边的荷载要大，中部的沉降就要比两边大，箱涵可能开裂。 4、结构基础类型差别大。同一联桥梁中，混合使用不同基础如扩大基础和桩基础，或同时采用桩基础但桩径或桩长差别大时，或同时采用扩大基础但基底标高差异大时，也可能引起地基不均匀沉降。 5、分期建造的基础。在原有桥梁基础附近新建桥梁时，如分期修建的高速公路左右半幅桥梁，新建桥梁荷载或基础处理时引起地基土重新固结，均可能对原有桥梁基础造成较大沉降。 6、地基冻胀。在低于零度的条件下含水率较高的地基土因冰冻膨胀；一旦温度回升，冻土融化，地基下沉。因此地基的冰冻或融化均可造成不均匀沉降。 7、桥梁基础置于滑坡体、溶洞或活动断层等不良地质时，可能造成不均匀沉降。 8、桥梁建成以后，

原有地基条件变化。大多数天然地基和人工地基浸水后，尤其是素填土、黄土、膨胀土等特殊地基土，土体强度遇水下降，压缩变形加大。在软土地基中，因人工抽水或干旱季节导致地下水位下降，地基土层重新固结下沉，同时对基础的上浮力减小，负摩阻力增加，基础受荷加大。有些桥梁基础埋置过浅，受洪水冲刷、淘挖，基础可能位移。地面荷载条件的变化，如桥梁附近因塌方、山体滑坡等原因堆置大量废方、砂石等，桥址范围土层可能受压缩再次变形。因此，使用期间原有地基条件变化均可能造成不均匀沉降。对于拱桥等产生水平推力的结构物，对地质情况掌握不够、设计不合理和施工时破坏了原有地质条件是产生水平位移裂缝的主要原因。

预应力混凝土使建造特殊形状的建筑物成为可能,如一些具有不受任何支撑物阻挡视线的大空间的现代体育竞技场。这种相对较新的结构方法的利用正在处于不断发展之中。