专业外文翻译

1、常州工学院土建学院 2011 届毕业设计专业外文翻译 专专业业土木工程 姓姓名名刘燕 班班级级07 土 Y1 学学号号07121318 指导教师指导教师苏康陆嘉平 2011 年1月14日 常州工学院土建学院 目目录录 1 外文原文.1 1.1 Reinforced Concrete.1 1.2 Earthwork.2 1.3 Safety of Structures.4 2 中文翻译. 7 2.1 钢筋混凝土. 7 2.2 土方工程. 8 2.3 结构的安全度. 9 常州工学院土建学院 1 1 1 外文翻译外文翻译 1.1 Reinforced Concrete Plain concrete

2、is formed from a hardened mixture of cement ,water ,fine aggregate, coarse aggregate (crushed stone or gravel),air, and often other admixtures. The plastic mix is placed and consolidated in the formwork, then cured to facilitate the acceleration of the chemical hydration reaction lf the cement/water

3、 mix, resulting in hardened concrete. The finished product has high compressive strength, and low resistance to tension, such that its tensile strength is approximately one tenth lf its compressive strength. Consequently, tensile and shear reinforcement in the tensile regions of sections has to be p

4、rovided to compensate for the weak tension regions in the reinforced concrete element. It is this deviation in the composition of a reinforces concrete section from the homogeneity of standard wood or steel sections that requires a modified approach to the basic principles of structural design. The

5、two components of the heterogeneous reinforced concrete section are to be so arranged and proportioned that optimal use is made of the materials involved. This is possible because concrete can easily be given any desired shape by placing and compacting the wet mixture of the constituent ingredients

6、are properly proportioned, the finished product becomes strong, durable, and, in combination with the reinforcing bars, adaptable for use as main members of any structural system. The techniques necessary for placing concrete depend on the type of member to be cast: that is, whether it is a column,

7、a bean, a wall, a slab, a foundation. a mass columns, or an extension of previously placed and hardened concrete. For beams, columns, and walls, the forms should be well oiled after cleaning them, and the reinforcement should be cleared of rust and other harmful materials. In foundations, the earth

8、should be compacted and thoroughly moistened to about 6 in. in depth to avoid absorption of the moisture present in the wet concrete. Concrete should always be placed in horizontal layers which are compacted by means of high frequency power-driven vibrators of either the immersion or external type,

9、as the case requires, unless it is placed by pumping. It must be kept in mind, however, that over vibration can be harmful since it could cause segregation of the aggregate and bleeding of the concrete. Hydration of the cement takes place in the presence of moisture at temperatures 常州工学院土建学院 2 above

10、 50F. It is necessary to maintain such a condition in order that the chemical hydration reaction can take place. If drying is too rapid, surfacecrackingtakesplace.Thiswouldresultinreductionof concrete strength due to cracking as well as the failure to attain full chemical hydration. It is clear that

11、 a large number of parameters have to be dealt with in proportioning a reinforced concrete element, such as geometrical width, depth, area of reinforcement, steel strain, concrete strain, steel stress, and so on. Consequently, trial and adjustment is necessary in the choice of concrete sections, wit

12、h assumptions based on conditions at site, availability of the constituent materials, particular demands of the owners, architectural and headroom requirements, the applicable codes, and environmental reinforced concrete is often a site-constructed composite, in contrast to the standard mill-fabrica

13、ted beam and column sections in steel structures. A trial section has to be chosen for each critical location in a structural system. The trial section has to be analyzed to determine if its nominal resisting strength is adequate to carry the applied factored load. Since more than one trial is often

14、 necessary to arrive at the required section, the first design input step generates into a series of trial-and- adjustment analyses. The trial-and adjustment procedures for the choice of a concrete section lead to the convergence of analysis and design. Hence every design is an analysis once a trial

15、 section is chosen. The availability of handbooks, charts, and personal computers and programs supports this approach as a more efficient, compact, and speedy instructional method compared with the traditional approach of treating the analysis of reinforced concrete separately from pure design. 1.2

16、Earthwork Because earthmoving methods and costs change more quickly than those in any other branch of civil engineering, this is a field where there are real opportunities for the enthusiast. In 1935 most of the methods now in use for carrying and excavating earth with rubber-tyred equipment did not

17、 exist. Most earth was moved by narrow rail track, now relatively rare, and the main methods of excavation, with face shovel, backacter, or dragline or grab, though they are still widely used are only a few of the many current methods. To keep his knowledge of earthmoving equipment up to date an eng

18、ineer must therefore spend tine studying modern machines. Generally the only reliable up-to-date information on excavators, loaders and transport is obtainable from the makers. 常州工学院土建学院 3 Earthworks or earthmoving means cutting into ground where its surface is too high ( cuts ), and dumping the ear

19、th in other places where the surface is too low ( fills). Toreduce earthwork costs, the volume of the fills should be equal to the volume of the cuts and wherever possible the cuts should be placednear to fills of equal volume so as to reduce transport and double handlingof the fill. This work of ea

20、rthwork design falls on the engineer who lays out the road since it is the layout of the earthwork more than anything else which decides its cheapness. From the available maps ahd levels, the engineering must try to reach as many decisions as possible in the drawing office by drawing cross sections

21、of the earthwork. On the site when further information becomes available he can make changes in jis sections and layout,but the drawing lffice work will not have been lost. It will have helped him to reach the best solution in the shortest time. The cheapest way of moving earth is to take it directl

22、y out of the cut and drop it as fill with the same machine. This is not always possible, but when it canbe done it is ideal, being both quick and cheap. Draglines, bulldozers and face shovels an do this. The largest radius is obtained with the dragline,and the largest tonnage of earth is moved by th

23、e bulldozer, though only over short distances.The disadvantages of the dragline are that it must dig below itself, it cannot dig with force into compacted material, it cannot dig on steep slopws, and its dumping and digging are not accurate. Face shovels are between bulldozers and draglines, having

24、a larger radius of action than bulldozers but less than draglines. They are anle to dig into a vertical cliff face in a way which would be dangerous tor a bulldozer operator and impossible for a dragline. Each piece of equipment should be level of their tracks and for deep digs in compact material a

25、 backacter is most useful, but its dumping radius is considerably less than that of the same escavator fitted with a face shovel. Rubber-tyred bowl scrapers are indispensable for fairly level digging where the distance of transport is too much tor a dragline or face shovel. They can dig the material

26、 deeply ( but only below themselves ) to a fairly flat surface, carry it hundreds of meters if need be, then drop it and level it roughly during the dumping. For hard digging it is often found economical to keep a pusher tractor ( wheeled or tracked ) on the digging site, to push each scraper as it

27、returns to dig. As soon as the scraper is full,the pusher tractor returns to the beginning of the dig to heop to help the nest scraper. Bowl scrapers are often extremely powerful machines;many makers build scrapers of 8 cubic meters struck capacity, which carry 10 m heaped. The largest self-propelle

28、d 常州工学院土建学院 4 scrapers are of 19 m struck capacity ( 25 m heaped )and they are driven by a tractor engine of 430 horse-powers. Dumpers are probably the commonest rubber-tyred transport since they can also conveniently be used for carrying concrete or other building materials. Dumpers have the earth

29、container over the front axle on large rubber-tyred wheels, and the container tips forwards on most types, though in articulated dumpers the direction of tip can be widely varied. The smallest dumpers have a capacity of about 0.5 m , and the largest standard types are of about 4.5 m . Special types

30、include the self-loading dumper of up to 4 m and the articulated type of about 0.5 m . The distinction between dumpers and dump trucks must be remembered .dumpers tip forwards and the driver sits behind the load. Dump trucks are heavy, strengthened tipping lorries, the driver travels in front lf the

31、 load and the load is dumped behind him, so they are sometimes called rear-dump trucks. 1.3 Safety of Structures The principal scope of specifications is to provide general principles and computational methods in order to verify safety of structures. The “ safety factor ”, which according to modern

32、trends is independent of the nature and combination of the materials used, can usually be defined as the ratio between the conditions. This ratio is also proportional to the inverse of the probability ( risk ) of failure of the structure. Failure has to be considered not only as overall collapse of

33、the structure but also as unserviceability or, according to a more precise. Common definition. As the reaching of a “ limit state ” which causes the construction not to accomplish the task it was designed for. There are two categories of limit state : (1)Ultimate limit sate, which corresponds to the

34、 highest value of the load-bearing capacity. Examples include local buckling or global instability of the structure; failure of some sections and subsequent transformation of the structure into a mechanism; failure by fatigue; elastic or plastic deformation or creep that cause a substantial change o

35、f the geometry of the structure; and sensitivity of the structure to alternating loads, to fire and to explosions. (2)Service limit states, which are functions of the use and durability of the structure. Examples include excessive deformations and displacements without instability; early or excessiv

36、e cracks; large vibrations; and corrosion. Computational methods used to verify structures with respect to the different safety conditions can be separated into: (1)Deterministic methods, in which the main parameters are considered as 常州工学院土建学院 5 nonrandom parameters. (2)Probabilistic methods, in wh

37、ich the main parameters are considered as random parameters. Alternatively, with respect to the different use of factors of safety, computational methods can be separated into: (1)Allowable stress method, in which the stresses computed under maximum loads are compared with the strength of the materi

38、al reduced by given safety factors. (2)Limit states method, in which the structure may be proportioned on the basis of its maximum strength. This strength, as determined by rational analysis, shall not be less than that required to support a factored load equal to the sum of the factored live load a

39、nd dead load ( ultimate state ). The stresses corresponding to working ( service ) conditions with unfactored live and dead loads are compared with prescribed values ( service limit state ) . From the four possible combinations of the first two and second two methods, we can obtain some useful compu

40、tational methods. Generally, two combinations prevail: (1)deterministic methods, which make use of allowable stresses. (2)Probabilistic methods, which make use of limit states. The main advantage of probabilistic approaches is that, at least in theory, it is possible to scientifically take into acco

41、unt all random factors of safety, which are then combined to define the safety factor. probabilistic approaches depend upon : (1) Random distribution of strength of materials with respect to the conditions of fabrication and erection ( scatter of the values of mechanical properties through out the s

42、tructure ); (2) Uncertainty of the geometry of the cross-section sand of the structure ( faults and imperfections due to fabrication and erection of the structure ); (3) Uncertainty of the predicted live loads and dead loads acting on the structure; (4)Uncertainty related to the approximation of the

43、 computational method used ( deviation of the actual stresses from computed stresses ). Furthermore, probabilistic theories mean that the allowable risk can be based on several factors, such as : (1) Importance of the construction and gravity of the damage by its failure; (2)Number of human lives wh

44、ich can be threatened by this failure; (3)Possibility and/or likelihood of repairing the structure; (4) Predicted life of the structure. 常州工学院土建学院 6 All these factors are related to economic and social considerations such as： (1) Initial cost of the construction; (2) Amortization funds for the durat

45、ion of the construction; (3) Cost of physical and material damage due to the failure of the construction; (4) Adverse impact on society; (5) Moral and psychological views. The definition of all these parameters, for a given safety factor, allows construction at the optimum cost. However, the difficu

46、lty of carrying out a complete probabilistic analysis has to be taken into account. For such an analysis the laws of the distribution of the live load and its induced stresses, of the scatter of mechanical properties of materials, and of the geometry of the cross-sections and the structure have to b

47、e known. Furthermore, it is difficult to interpret the interaction between the law of distribution of strength and that of stresses because both depend upon the nature of the material, on the cross-sections and upon the load acting on the structure. These practical difficulties can be overcome in tw

48、o ways. The first is to apply different safety factors to the material and to the loads, without necessarily adopting the probabilistic criterion. The second is an approximate probabilistic method which introduces some simplifying assumptions ( semi-probabilistic methods ) . 常州工学院土建学院 7 2 2 中文翻译中文翻译

49、 2.1 钢筋混凝土 素混凝土是由水泥、水、细骨料、粗骨料（碎石或；卵石） 、空气，通常还有 其他外加剂等经过凝固硬化而成。将可塑的混凝土拌合物注入到模板内，并将其捣 实，然后进行养护，以加速水泥与水的水化反应，最后获得硬化的混凝土。其最终 制成品具有较高的抗压强度和较低的抗拉强度。其抗拉强度约为抗压强度的十分之 一。因此，截面的受拉区必须配置抗拉钢筋和抗剪钢筋以增加钢筋混凝土构件中较 弱的受拉区的强度。 由于钢筋混凝土截面在均质性上与标准的木材或钢的截面存在着差异，因此， 需要对结构设计的基本原理进行修改。将钢筋混凝土这种非均质截面的两种组成部 分按一定比例适当布置，可以最好的利用这两种材料

50、。这一要求是可以达到的。因 混凝土由配料搅拌成湿拌合物，经过振捣并凝固硬化，可以做成任何一种需要的形 状。如果拌制混凝土的各种材料配合比恰当，则混凝土制成品的强度较高，经久耐 用，配置钢筋后，可以作为任何结构体系的主要构件。 浇筑混凝土所需要的技术取决于即将浇筑的构件类型，诸如：柱、梁、墙、板、 基础，大体积混凝土水坝或者继续延长已浇筑完毕并且已经凝固的混凝土等。对于 梁、柱、墙等构件，当模板清理干净后应该在其上涂油，钢筋表面的锈及其他有害 物质也应该被清除干净。浇筑基础前，应将坑底土夯实并用水浸湿 6 英寸，以免土 壤从新浇的混凝土中吸收水分。一般情况下，除使用混凝土泵浇筑外，混凝土都应 在

51、水平方向分层浇筑，并使用插入式或表面式高频电动振捣器捣实。必须记住，过 分的振捣将导致骨料离析和混凝土泌浆等现象，因而是有害的。 水泥的水化作用发生在有水分存在，而且气温在 50F 以上的条件下。为了保 证水泥的水化作用得以进行， 必须具备上述条件。 如果干燥过快则会出现表面裂缝， 这将有损与混凝土的强度，同时也会影响到水泥水化作用的充分进行。 设计钢筋混凝土构件时显然需要处理大量的参数， 诸如宽度、 高度等几何尺寸， 配筋的面积，钢筋的应变和混凝土的应变，钢筋的应力等等。因此，在选择混凝土 截面时需要进行试算并作调整，根据施工现场条件、混凝土原材料的供应情况、业 主提出的特殊要求、对建筑和净

52、空高度的要求、所用的设计规范以及建筑物周围环 境条件等最后确定截面。钢筋混凝土通常是现场浇注的合成材料，它与在工厂中制 造的标准的钢结构梁、 柱等不同， 因此对于上面所提到的一系列因素必须予以考虑。 对结构体系的各个部位均需选定试算截面并进行验算，以确定该截面的名义强 度是否足以承受所作用的计算荷载。由于经常需要进行多次试算，才能求出所需的 截面，因此设计时第一次采用的数值将导致一系列的试算与调整工作。 常州工学院土建学院 8 选择混凝土截面时， 采用试算与调整过程可以使复核与设计结合在一起。 因此， 当试算截面选定后，每次设计都是对截面进行复核。手册、图表和微型计算机以及 专用程序的使用，使

53、这种设计方法更为简捷有效，而传统的方法则是把钢筋混凝土 的复核与单纯的设计分别进行处理。 2.2 土方工程 由于和土木工程中任何其他工种的施工方法与费用相比较，土方挖运的施工方 法与费用的变化都要快得多，因此对于有事业心的人来说，土方工程是一个可以大 有作为的领域。在 1935 年，目前采用的利用轮胎式机械设备进行土方挖运的方法 大多数还没有出现。那是大部分土方是采用窄轨铁路运输，在这目前来说是很少采 用的。当时主要的开挖方式是使用正铲、反铲、拉铲或抓斗等挖土机，尽管这些机 械目前仍然在广泛应用，但是它们只不过是目前所采用的许多方法中的一小部分。 因此，一个工程师为了使自己在土方挖运设备方面的

54、知识跟得上时代的发展，他应 当花费一些时间去研究现代的机械。一般说来，有关挖土机、装载机和运输机械的 唯一可靠而又最新的资料可以从制造厂商处获得。 土方工程或土方挖运工程指的是把地表面过高处的土壤挖去（挖方） ，并把它 倾卸到地表面过低的其他地方（填方） 。为了降低土方工程费用，填方量应该等于 挖方量，而且挖方地点应该尽可能靠近土方量相等的填方地点，以减少运输量和填 方的二次搬运。土方设计这项工作落到了从事道路设计的工程师的身上，因为土方 工程的设计比其他任何工作更能决定工程造价是否低廉。根据现有的地图和标高， 道路工程师应在设计绘图室中的工作也并不是徒劳的。它将帮助他在最短的时间内 获得最好

55、的方案。 费用最低的运土方法是用同一台机械直接挖方取土并且卸土作为填方。这并不 是经常可以做到的，但是如果能够做到则是很理想的，因为这样做既快捷又省钱。 拉铲挖土机。推土机和正铲挖土机都能做到这点。拉铲挖土机的工作半径最大。推 土机所推运的图的数量最多，只是运输距离很短。拉铲挖土机的缺点是只能挖比它 本身低的土，不能施加压力挖入压实的土壤内，不能在陡坡上挖土，而且挖。卸都 不准确。 正铲挖土机介于推土机和拉铲挖土机的之间，其作用半径大于推土机，但小于 拉铲挖土机。正铲挖土机能挖取竖直陡峭的工作面，这种方式对推土机司机来说是 危险的，而对拉铲挖土机则是不可能的。每种机械设备应该进行最适合它的性能的 作业。正铲挖土机不能挖比其停机平面低很多的土，而深挖坚实的土壤时，反铲挖 土机最适用，但其卸料半径比起装有正铲的同一挖土机的卸料半径则要小很多。 在比较平坦的场地开挖，如果用拉铲或正铲挖土机运输距离太远时，则装有轮 胎式的斗式铲运机就是比不可少的。它能在比较平的地面上挖较深的土（但只能挖 常州工学院土建学院 9 机械本身下面的土） ，需要时可以将土运至几百米远，然后卸土并在卸土的过程中 把土大致铲平。在挖掘硬土时，人们发现在开挖场地经常用一辆助推拖拉机（轮式 或履带式） ，对返回挖土的铲运机进行助推这种施工方法是经济的。一旦铲运机装 满，助推拖