土木工程毕业论文中英文翻译1

1、外文翻译班级：xxx学号：xxx姓名：xxx、外文原文：Structural Systems to resist lateral loadsCommonly Used structural SystemsWith loads measured in tens of thousands kips, there is little room in the design of high-rise buildingsfor excessively complex thoughts. Indeed, the better high-rise buildings carry the universal t

2、raits ofsimplicity of thought and clarity of expression.It does not follow that there is no room for grand thoughts. Indeed, it is with such grand thoughts thatthe new family of high-rise buildings has evolved. Perhaps more important, the new concepts of but a fewyears ago have become commonplace in

3、 todays technology.Omitting some concepts that are related strictly to the materials of construction, the most commonlyused structural systems used in high-rise buildings can be categorized as follows:1.Moment-resisting frames.2.Braced frames, including eccentrically braced frames.3.Shear walls, inc

4、luding steel plate shear walls.4.Tube-in-tube structures.5.Core-interactive structures.6.Cellular or bundled-tube systems.Particularly with the recent trend toward more complex forms, but in response also to the need forincreased stiffness to resist the forces from wind and earthquake, most high-ris

5、e buildings have structuralsystems built up of combinations of frames, braced bents, shear walls, and related systems. Further, for thetaller buildings, the majorities are composed of interactive elements in three-dimensional arrays.The method of combining these elements is the very essence of the d

6、esign process for high-risebuildings. These combinations need evolve in response to environmental, functional, and costconsiderations so as to provide efficient structures that provoke the architectural development to newheights. This is not to say that imaginative structural design can create great

7、 architecture. To the contrary,many examples of fine architecture have been created with only moderate support from the structuralengineer, while only fine structure, not great architecture, can be developed without the genius and theleadership of a talented architect. In any event, the best of both

8、 is needed to formulate a truly extraordinarydesign of a high-rise building.While comprehensive discussions of these seven systems are generally available in the literature,further discussion is warranted here .The essence of the design process is distributed throughout thediscussion.Moment-Resistin

9、g FramesPerhaps the most commonly used system in low-to medium-rise buildings, the moment-resistingframe, is characterized by linear horizontal and vertical members connected essentially rigidly at their joints.Such frames are used as a stand-alone system or in combination with other systems so as t

10、o provide theneeded resistance to horizontal loads. In the taller of high-rise buildings, the system is likely to be foundinappropriate for a stand-alone system, this because of the difficulty in mobilizing sufficient stiffness underlateral forces.Analysis can be accomplished by STRESS, STRUDL, or a

11、 host of other appropriate computerprograms; analysis by the so-called portal method of the cantilever method has no place in todaystechnology.Because of the intrinsic flexibility of the column/girder intersection, and because preliminary designsshould aim to highlight weaknesses of systems, it is n

12、ot unusual to use center-to-center dimensions for theframe in the preliminary analysis. Of course, in the latter phases of design, a realistic appraisal in-jointdeformation is essential.Braced Frame sThe braced frame, intrinsically stiffer than the moment-esisting frame, finds also greater applicati

13、onto higher-rise buildings. The system is characterized by linear horizontal, vertical, and diagonal members,connected simply or rigidly at their joints. It is used commonly in conjunction with other systems for tallerbuildings and as a stand-alone system in low-to medium-rise buildings.While the us

14、e of structural steel in braced frames is common, concrete frames are more likely to be ofthe larger-scale variety.Of special interest in areas of high seismicity is the use of the eccentric braced frame.Again, analysis can be by STRESS, STRUDL, or any one of a series of two -or three dimensionalana

15、lysis computer programs. And again, center-to-center dimensions are used commonly in thepreliminary analysis.Shear wallsThe shear wall is yet another step forward along a progression of ever-stiffer structural systems. Thesystem is characterized by relatively thin, generally (but not always) concret

16、e elements that provide bothstructural strength and separation between building functions.In high-rise buildings, shear wall systems tend to have a relatively high aspect ratio, that is, theirheight tends to be large compared to their width. Lacking tension in the foundation system, any structuralel

17、ement is limited in its ability to resist overturning moment by the width of the system and by the gravityload supported by the element. Limited to a narrow overturning, One obvious use of the system, whichdoes have the needed width, is in the exterior walls of building, where the requirement for wi

18、ndows is keptsmall.Structural steel shear walls, generally stiffened against buckling by a concrete overlay, have foundapplication where shear loads are high. The system, intrinsically more economical than steel bracing, isparticularly effective in carrying shear loads down through the taller floors

19、 in the areas immediately abovegrade. The system has the further advantage of having high ductility a feature of particular importance inareas of high seismicity.The analysis of shear wall systems is made complex because of the inevitable presence of largeopenings through these walls. Preliminary an

20、alysis can be by truss-analogy, by the finite element method,or by making use of a proprietary computer program designed to consider the interaction, or coupling, ofshear walls.Framed or Braced TubesThe concept of the framed or braced or braced tube erupted into the technology with the IBM Buildingi

21、n Pittsburgh, but was followed immediately with the twin 110-story towers of the World Trade Center, NewYork and a number of other buildings .The system is characterized by three -dimensional frames, bracedframes, or shear walls, forming a closed surface more or less cylindrical in nature, but of ne

22、arly any planconfiguration. Because those columns that resist lateral forces are placed as far as possible from thecancroids of the system, the overall moment of inertia is increased and stiffness is very high.The analysis of tubular structures is done using three-dimensional concepts, or by twodime

23、nsionalanalogy, where possible, whichever method is used, it must be capable of accounting for the effects ofshear lag.The presence of shear lag, detected first in aircraft structures, is a serious limitation in the stiffness offramed tubes. The concept has limited recent applications of framed tube

24、s to the shear of 60 stories.Designers have developed various techniques for reducing the effects of shear lag, most noticeably the useof belt trusses. This system finds application in buildings perhaps 40stories and higher. However, exceptfor possible aesthetic considerations, belt trusses interfer

25、e with nearly every building function associatedwith the outside wall; the trusses are placed often at mechanical floors, mush to the disapproval of thedesigners of the mechanical systems. Nevertheless, as a cost-effective structural system, the belt trussworks well and will likely find continued ap

26、proval from designers. Numerous studies have sought tooptimize the location of these trusses, with the optimum location very dependent on the number of trussesprovided. Experience would indicate, however, that the location of these trusses is provided by theoptimization of mechanical systems and by

27、aesthetic considerations, as the economics of the structuralsystem is not highly sensitive to belt truss location.Tube-in-Tube StructuresThe tubular framing system mobilizes every column in the exterior wall in resisting over-turning andshearing forces. The termtube-in-tubeis largely self-explanator

28、y in that a second ring of columns, thering surrounding the central service core of the building, is used as an inner framed or braced tube. Thepurpose of the second tube is to increase resistance to over turning and to increase lateral stiffness. Thetubes need not be of the same character; that is,

29、 one tube could be framed, while the other could bebraced.In considering this system, is important to understand clearly the difference between the shear andthe flexural components of deflection, the terms being taken from beam analogy. In a framed tube, theshear component of deflection is associate

30、d with the bending deformation of columns and girders (i.e, thewebs of the framed tube) while the flexural component is associated with the axial shortening andlengthening of columns (i.e, the flanges of the framed tube). In a braced tube, the shear component ofdeflection is associated with the axia

31、l deformation of diagonals while the flexural component of deflection isassociated with the axial shortening and lengthening of columns.Following beam analogy, if plane surfaces remain plane (i.e, the floor slabs),then axial stresses in thecolumns of the outer tube, being farther form the neutral ax

32、is, will be substantially larger than the axialstresses in the inner tube. However, in the tube-in-tube design, when optimized, the axial stresses in theinner ring of columns may be as high, or even higher, than the axial stresses in the outer ring. This seeminganomaly is associated with differences

33、 in the shearing component of stiffness between the two systems.This is easiest to under-stand where the inner tube is conceived as a braced (i.e, shear-stiff) tube while theouter tube is conceivedas aframed (i.e, shear-flexible) tube.Core Interactive StructuresCore interactive structures are a spec

34、ial case of a tube-in-tube wherein the two tubes are coupledtogether with some form of three-dimensional space frame. Indeed, the system is used often wherein theshear stiffness of the outer tube is zero. The United States Steel Building, Pittsburgh, illustrates the systemvery well. Here, the inner

35、tube is a braced frame, the outer tube has no shear stiffness, and the two systemsare coupled if they were considered as systems passing in a straight line from the“hat s”tructure. Notethat the exterior columns would be improperly modeled if they were considered as systems passing in astraight line

36、from the“hat t”o the foundations; these columns are perhaps 15% stiffer as they follow theelastic curve of the braced core. Note also that the axial forces associated with the lateral forces in the innercolumns change from tension to compression over the height of the tube, with the inflection point

37、 at about5/8 of the height of the tube. The outer columns, of course, carry the same axial force under lateral load forthe full height of the columns because the columns because the shear stiffness of the system is close tozero.The space structures of outrigger girders or trusses, that connect the i

38、nner tube to the outer tube, arelocated often at several levels in the building. The AT&T headquarters is an example of an astonishingarray of interactive elements:1.The structural system is 94 ft (28.6m) wide, 196ft(59.7m) long, and 601ft (183.3m) high.2.Two inner tubes are provided, each 31ft(9.4m

39、) by 40 ft (12.2m), centered 90 ft (27.4m) apart in the longdirection of the building.3.The inner tubes are braced in the short direction, but with zero shear stiffness in the long direction.4.A single outer tube is supplied, which encircles the building perimeter.5.The outer tube is a moment-resist

40、ing frame, but with zero shear stiffness for the center50ft(15.2m) of each of the long sides.6.A space-truss hat structure is provided at the top of the building.7.A similar space truss is located near the bottom of the building8.The entire assembly is laterally supported at the base on twin steel-p

41、late tubes, because the shearstiffness of the outer tube goes to zero at the base of the building.Cellular structuresA classic example of a cellular structure is the Sears Tower, Chicago, a bundled tube structure of nineseparate tubes. While the Sears Tower contains nine nearly identical tubes, the

42、basic structural system hasspecial application for buildings of irregular shape, as the several tubes need not be similar in plan shape,It is not uncommon that some of the individual tubes one of the strengths and one of the weaknesses of thesystem.This special weakness of this system, particularly

43、in framed tubes, has to do with the concept ofdifferential column shortening. The shortening of a column under load is given by the expression=2fL/EFor buildings of 12 ft (3.66m) floor-to-floor distances and an average compressive stress of 15 ksi(138MPa), the shortening of a column under load is 15

44、 (12)(12)/29,000 or 0.074in (1.9mm) per story. At 50stories, the column will have shortened to 3.7 in. (94mm) less than its unstressed length. Where one cell ofa bundled tube system is, say, 50stories high and an adjacent cell is, say, 100stories high, those columnsnear the boundary between .the two

45、 systems need to have this differential deflection reconciled.Major structural work has been found to be needed at such locations. In at least one building, the RialtoProject, Melbourne, the structural engineer found it necessary to vertically pre-stressthe lower height columns so as to reconcile th

46、e differential deflections of columns in close proximity withthe post-tensioning of the shorter column simulating the weight to be added on to adjacent, highercolumns.二、原文翻译：抗侧向荷载的结构体系常用的结构体系 若已测出荷载量达数千万磅重， 那么在高层建筑设计中就没有多少可以进行极其复杂的 构思余地了。确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。这并不是说没有进行宏观构思的余地。实际上，正是因为有了这种宏观的构思，

47、新 奇的高层建筑体系才得以发展， 可能更重要的是： 几年以前才出现的一些新概念在今天 的技术中已经变得平常了。如果忽略一些与建筑材料密切相关的概念不谈， 高层建筑里最为常用的结构体系便 可分为如下几类：1 抗弯矩框架。2 支撑框架，包括偏心支撑框架。3 剪力墙，包括钢板剪力墙。4 筒中框架。5 筒中筒结构。6 核心交互结构。7 框格体系或束筒体系。特别是由于最近趋向于更复杂的建筑形式， 同时也需要增加刚度以抵抗几力和地震 力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的 体系。而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。将这些构件结合起来的方法正是高层

48、建筑设计方法的本质。 其结合方式需要在 考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。 这并不是说富于想象力的结构设计就能够创造出伟大建筑。正相反， 有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了， 然而， 如果没有天赋甚厚的建筑师的创造力的指导， 那么，得以发展的就只能是好的结构， 并非是伟大的建筑。 无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值 得进一步讨论。 设计方法的本质贯穿于整个讨论。 设计方法的本质贯穿于整个讨论 中。抗弯矩框架抗弯矩框架也许是低， 中高度的建筑

49、中常用的体系， 它具有线性水平构件和垂 直构件在接头处基本刚接之特点。 这种框架用作独立的体系， 或者和其他体系结合 起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该 本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。我们可以利用STRESS，STRUDL或者其他大量合适的计算机程序进行结构分 析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地， 由于柱梁节点固 有柔性，并且由于初步设计应该力求突出体系的弱点， 所以在初析中使用框架的中 心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有 必要。支撑框架支撑框架实际上刚度比抗弯

50、矩框架强， 在高层建筑中也得到更广泛的应用。 这 种体系以其结点处铰接或则接的线性水平构件、 垂直构件和斜撑构件而具特色， 它 通常与其他体系共同用于较高的建筑， 并且作为一种独立的体系用在低、 中高度的 建筑中。尤其引人关注的是，在强震区使用偏心支撑框架。此外，可以利用STRESS，STRUDL，或一系列二维或三维计算机分析程序中的任何一种进行结构分析。另外，初步分析中常用中心距尺寸。剪力墙剪力墙在加强结构体系刚性的发展过程中又前进了一步。 该体系的特点是具有 相当薄的，通常是（而不总是）混凝土的构件，这种构件既可提供结构强度，又可 提供建筑物功能上的分隔。在高层建筑中，剪力墙体系趋向于具有

51、相对大的高宽经，即与宽度相比，其高 度偏大。 由于基础体系缺少应力， 任何一种结构构件抗倾覆弯矩的能力都受到体系 的宽度和构件承受的重力荷载的限制。 由于剪力墙宽度狭狭窄受限， 所以需要以某 种方式加以扩大， 以便提从所需的抗倾覆能力。 在窗户需要量小的建筑物外墙中明 显地使用了这种确有所需要宽度的体系。钢结构剪力墙通常由混凝土覆盖层来加强以抵抗失稳， 这在剪切荷载大的地方 已得到应用。 这种体系实际上比钢支撑经济， 对于使剪切荷载由位于地面正上方区 域内比较高的楼层向下移特别有效。这种体系还具有高延性之优点，这种特性在强 震区特别重要。由于这些墙内必然出同一些大孔，使得剪力墙体系分析变得错综

52、复杂。 可以通 过桁架模似法、 有限元法， 或者通过利用为考虑剪力墙的交互作用或扭转功能设计 的专门计处机程序进行初步分析框架或支撑式筒体结构：框架或支撑式筒体最先应用于IBM公司在Pittsburgh的一幢办公楼，随后立即被应用 于纽约双子座的110层世界贸易中心摩天大楼和其他的建筑中。 这种系统有以下几个显著的 特征：三维结构、支撑式结构、或由剪力墙形成的一个性质上差不多是圆柱体的闭合曲面， 但又有任意的平面构成。由于这些抵抗侧向荷载的柱子差不多都被设置在整个系统的中心， 所以整体的惯性得到提高，刚度也是很大的。在可能的情况下，通过三维概念的应用、二维的类比，我们可以进行筒体结构的分析。

53、不管应用那种方法，都必须考虑剪力滞后的影响。这种最先在航天器结构中研究的剪力滞后出现后，对筒体结构的刚度是一个很大的限 制。这种观念已经影响了筒体结构在60层以上建筑中的应用。设计者已经开发出了很多的 技术，用以减小剪力滞后的影响，这其中最有名的是桁架的应用。框架或支撑式筒体在40层或稍高的建筑中找到了自己的用武之地。 除了一些美观的考虑外， 桁架几乎很少涉及与外 墙联系的每个建筑功能， 而悬索一般设置在机械的地板上， 这就令机械体系设计师们很不赞 成。但是， 作为一个性价比较好的结构体系， 桁架能充分发挥它的性能，所以它会得到设计 师们持续的支持。 由于其最佳位置正取决于所提供的桁架的数量，

54、 因此很多研究已经试图完 善这些构件的位置。 实验表明： 由于这种结构体系的经济性并不十分受桁架位置的影响， 所 以这些桁架的位置主要取决于机械系统的完善，审美的要求， 筒中筒结构：筒体结构系统能使外墙中的柱具有灵活性，用以抵抗颠覆和剪切力。“筒中筒”这个名字顾名思义就是在建筑物的核心承重部分又被包围了第二层的一系列柱子， 它们被当作是框 架和支撑筒来使用。配置第二层柱的目的是增强抗颠覆能力和增大侧移刚度。 这些筒体不是 同样的功能，也就是说，有些筒体是结构的，而有些筒体是用来支撑的。在考虑这种筒体时，清楚的认识和区别变形的剪切和弯曲分量是很重要的，这源于对 梁的对比分析。在结构筒中，剪切构件

55、的偏角和柱、纵梁（例如：结构筒中的网等）的弯曲 有关，同时，弯曲构件的偏角取决于柱子的轴心压缩和延伸（例如：结构筒的边缘等） 。在 支撑筒中， 剪切构件的偏角和对角线的轴心变形有关， 而弯曲构件的偏角则与柱子的轴心压 缩和延伸有关。根据梁的对比分析，如果平面保持原形（例如：厚楼板） ，那么外层筒中柱的轴心压力 就会与中心筒柱的轴心压力相差甚远， 而且稳定的大于中心筒。 但是在筒中筒结构的设计中， 当发展到极限时， 内部轴心压力会很高的， 甚至远远大于外部的柱子。 这种反常的现象是由 于两种体系中的剪切构件的刚度不同。 这很容易去理解， 内筒可以看成是一个支撑 （或者说 是剪切刚性的）筒，而外筒

56、可以看成是一个结构（或者说是剪切弹性的）筒。核心交互式结构：核心交互式结构属于两个筒与某些形式的三维空间框架相配合的筒中筒特殊情况。事 实上，这种体系常用于那种外筒剪切刚度为零的结构。位于Pittsburgh的美国钢铁大楼证实 了这种体系是能很好的工作的。 在核心交互式结构中， 内筒是一个支撑结构， 外筒没有任何 剪切刚度， 而且两种结构体系能通过一个空间结构或“帽”式结构共同起作用。需要指出的 是，如果把外部的柱子看成是一种从“帽”到基础的直线体系，这将是不合适的；根据支撑 核心的弹性曲线，这些柱子只发挥了刚度的15%。同样需要指出的是，内柱中与侧向力有关的轴向力沿筒高度由拉力变为压力，同时

57、变化点位于筒高度的约 递相同的轴向力，这种轴向力低于作用在整个柱子高度的侧向荷载，因为这个体系的剪切刚 度接近于零。把内外筒相连接的空间结构、悬臂梁或桁架经常遵照一些规范来布置。美国电话电报 总局就是一个布置交互式构件的生动例子。1、 结构体系长59.7米，宽28.6米，高183.3米。2、布置了两个筒，每个筒的尺寸是9.4米X12.2米，在长方向上有27.4米的间隔。3、 在短方向上内筒被支撑起来，但是在长方向上没有剪切刚度。4、 环绕着建筑物布置了一个外筒。5、 外筒是一个瞬时抵抗结构，但是在每个长方向的中心15.2米都没有剪切刚度。6、 在建筑的顶部布置了一个空间桁架构成的“帽式”结构。

58、7、 在建筑的底部布置了一个相似的空间桁架结构。8、 由于外筒的剪切刚度在建筑的底部接近零，整个建筑基本上由两个钢板筒来支持。框格体系或束筒体系结构：位于美国芝加哥的西尔斯大厦是箱式结构的经典之作， 它由九个相互独立的筒组成的 一个集中筒。 由于西尔斯大厦包括九个几乎垂直的筒， 而且筒在平面上无须相似， 基本的结 构体系在不规则形状的建筑中得到特别的应用。 一些单个的筒高于建筑一点或很多是很常见 的。事实上，这种体系的重要特征就在于它既有坚固的一面，也有脆弱的一面。这种体系的脆弱，特别是在结构筒中，与柱子的压缩变形有很大的关系，柱子的压缩 变形有下式计算：=2fL/E对于那些层高为3.66米左右和平均压力为138MPa的建筑，在荷载作用下每层柱子的 压缩变形为15（12）/29000或1.9毫米。在第50层柱子会压缩94毫米， 小于它未受压的长 度。这些柱子在50层的时候和100层的时候的变形是不一样的，位于这两种体系之间接近 于边缘的那些柱需要使这种不均匀的变形得以调解。主要的结构工作都集中在布置中。 在Melbourne的Rialto项目中， 结构工程师发现至少 有一幢建筑， 很有必要垂直预压低高度的柱子， 以便使柱不均匀的变形差得以调解， 调解的 方法近似于后拉伸法，即较短的柱转移重量到较高的邻柱上。5/8处。当然，外柱也传