高層建筑結(jié)構(gòu)的發(fā)展-外文翻譯

1、<p>　　本科畢業(yè)設(shè)計外文翻譯</p><p>　　題目高層建筑結(jié)構(gòu)的發(fā)展</p><p>　　專 業(yè) 班 級 土木 </p><p>　　姓 名 </p><p>　　學(xué) 號 <

2、/p><p>　　指導(dǎo)教師及職稱 </p><p>　　Development of Structural Forms For Tall Buildings</p><p>　　The first steps towards the modern multistory building appear to have been tak

3、en in the Bronge Age, with the appearance of the emergence of proper cities. Even today there appears to be an instrinc relationship between the tall building, and the city. Multistory buildings were considered a charac

4、teristic of ancient Rome, and four and five-story wooden tenement buildings were common. Those built after the great fire of Nero used the new burnt brick and concrete materials in the form of arch and </p><p&

5、gt;　　Throughout the following centuries, the two basic materials used in building construction were timber and masonry, although the former lacked the strength required for buildings of more than about 16m in height, and

6、 always presented a fire hazard. The latter had the advantages of high compressive strength and fire resistance, but suffered from its high weight, which tended to overload the lower supports. The limits of this form of

7、construction became apparent in 1891 in the 16-story Monadnock Bu</p><p>　　The socio-econormic problems which followed the industrialization of the 19th century, allied to the insatiable demand for space in

8、the US cities, gave a big impetus to tall building construction. However, the growth could not have been sustained without two major technical innovations during the middle of that century, namely, the development of new

9、 higher strength and structurally more efficient materials, wrought iron and subsequently steel, and the introduction of the elevator to facilitate </p><p>　　The new material allowed the development of light

10、weight framed or skeletal structures, permitting greater heights and more and larger openings in the building. The forerunner of the steel frame which appeared in Chicago around 1890 may well have been a seven-story iron

11、-framed Manchester cotton mill, built in 1801,in which the contemporary I-beam shape appears to have been used for the first time. The Crystal Palace, built for the London International Exhibition of 1851, used a complet

12、ely autonom</p><p>　　Although the first elevator appeared in 1851, in a New York hotel, its potential in high-rise building was apparently not realized until its incorporation in the Equitable Life Insurance

13、 Company Building in New York in 1870. For the first time, this made the upper stories as attractive a renting proposition as the lower ones, and in so doing made the taller-than-average structure financially viable.<

14、/p><p>　　Improved steel design methods and construction techniques allowed steel-framed structure to grow steadily upwards, although progress slowed down during the period of the First World War. In 1909, the 5

15、0-story Metropolitan Tower Building. This golden age of American skyscraper construction culminated in 1931 in its crowning glory, the Empire State Building. Its 102 stories rose to a height of 381m which has now increas

16、ed to 449m with the addition of a TV aerial. The building used 57000t (US) of s</p><p>　　Although reinforced concrete construction began to be adopted seriously around the turn of the century, it dose not ap

17、pear to have been used properly for multistory buildings until after the end of the First World War. The inherent advantages of the composite material were not at that time fully appreciated, and the early systems were d

18、eveloped purely as imitations of steel structures. An early landmark was the 16-story Ingalls Building in Cincinnatti, Ohio, (1903), which was not superseded unti</p><p>　　The economic depression of the 1930

19、s put an end to the great skyscraper era, and it was not until some years after the end of the Second World War that the construction of high-rise building recommend, bringing with it new structural and architectural sol

20、ution. However, modern developments have produced new structural layouts, improved material qualities, and better design and construction techniques rather than significant increases in height.</p><p>　　Desi

21、gn philosophies altered during the period of recession and war. The earlier tall buildings were characterized by having heavy structural elements and being very stiff due to the high in-plane rigidities of the interior p

22、artitions and façade cladding with low areas of fenestrastion. However, modern office blocks tend to be characterized by light demountable partitions to aloe planning flexibility of occupancy, exterior glass curtain

23、 walls, and lighter sections as a result of high-strength con</p><p>　　The building frame was traditionally designed to resist the gravitational loads which are always present and form the reason for its ver

24、y existence. These loads derive from the self-weight of the vertical and horizontal structural components, including the cladding, and the superimposed floor loadings. There will give rise to necessary minimum cross-sect

25、ional areas, based on allowable stress levels, for the vertical column and wall elements, in the design.</p><p>　　In the past three decades, therefore, designers have sought to evolve structural systems whic

26、h will reduce as far as possible the cost and weight of materials, while simultaneously fulfilling the primary building function. A suitable arrangement of the vertical column and wall elements, allied to the horizontal

27、floor system, is required which will provide an economic method of resisting lateral forces and minimizing the additional height premium.</p><p>　　Although the provision of load paths for gravitational force

28、s is limited, there is considerable scope for organizing the structural system to resist lateral forces as efficiently as possible. This may be achieved by the judicious disposition of the vertical elements and their int

29、erconnection by horizontal structural components in order to resist moment by axial forces rather than bending moments in these vertical elements.</p><p>　　In general, different structural systems have evolv

30、ed for residential and office buildings have been constructed in which the two categories have been mixed, in a deliberate attempt to revitalize moribund city center areas.</p><p>　　The basic functional requ

31、irement of a residential building is the provision of discrete dwelling units for groups of individuals. These have common requirements of living, sleeping, cooking and toilet areas, which must be separated by partitions

32、 which offer fire and acoustic insulation between dwelling.</p><p>　　Framed structures may be usefully employed for residential buildings, since the presence of permanent partitions allows the column layout

33、to the correspond to the architectural plan. However, these depend on the rigidity of the joints for their resistance to lateral forces, and tend to become uneconomic at heights above 20-25 stories, depending on the over

34、all dimensions, when wind forces begin to control the design, and it becomes increasingly difficult to meet stiffness requirements. Since thei</p><p>　　In order to provide adequate fire and acoustic insulati

35、on between dwellings, infill panels of brickwork or blockwork are introduced into the frames. Although techniques exist for assessing the influence of these infill panels on the strength and stiffness of the frame, they

36、are generally assumed to be non-load-bearing, in view of the designer’s fear that they may be either removed or perforated for a change of function at some future date, as well as the difficulty of achieving a tight fit

37、betwe</p><p>　　Functional requirements for this form of building have given rise to the slab block of cross-wall construction, in which horizontal movement of occupants is achieved by long corridors running

38、along the length of the building, with apartments positioned on either side, or to point blocks in which apartments are grouped around the area of vertical transportation, lifts and stairwells. In each case, the basic st

39、ructure consists of orthogonal systems of shear walls, connected by floor slabs and perh</p><p>　　In a design, the shear walls must be sufficiently stiff to meet the imposed deflection criterion, and in addi

40、tion, should be so arranged that tensile stresses caused by wind forces are less than the compressive stresses produced by the weight of the building. A careful arrangement of walls can improve structural efficiency whic

41、h consists of a series of cross-walls and two flank walls running across the width of the building. As a reasonable approximation, each wall will carry the vertical loads </p><p>　　Shear wall structures are

42、well suited for resisting seismic loadings, and have performed well in recent disasters. They tend to become economical as soon as lateral forces affect the design and proportioning of flat plate or framed systems. Howev

43、er, they do possess the disadvantage of an inherent lack of flexibility for future modifications, while discontinuities are frequently required at the critical ground level area to provide a different architectural funct

44、ion on the ground floor, and speci</p><p>　　A relative recent innovation which is particularly suitable for residential blocks is the staggered wall-beam system. The structure consists of a series of paralle

45、l bents, each comprising columns with perforated story-height walls between them, in alternate bays. Each wall panel acts in conjunction with, and supports, the slab above and below to form a composite I-beam. By this de

46、vice, large clear areas are created on each floor, yet the floor slabs span only half the distance between adjacent w</p><p>　　The essential functional requirement of an office building is the provision of a

47、reas unobstructed as possible by walls or columns to allow each occupant to design the partitioning and space enclosure most suitable for his particular business organization. The partition layout will generally alter wh

48、en tenants change, and this necessitates flexibility in the distribution of the various services to any particular floor. As a result, services tend to be carried vertically within one or more service</p><p>

49、;　　By judicious planning of the column layout to maximize the open floor areas, shear wall-frame interactive structures may also be employed for office blocks, although the presence of the columns may make it difficult t

50、o achieve the desired planning flexibility.</p><p>　　Possibly the simplest method of creating open floor areas is to use a central concrete shear core, which carries all essential services and which is desig

51、ned to resist all lateral forces. The floor system spans between the central core and the exterior façade columns, and a large unobstructed floor area is created between the two vertical components. The exterior col

52、umns can be designed to be effectively pin-connected at each floor level, so that they transmit vertical forces only, in conjunctio</p><p>　　In some situations, a different architectural arrangement is desir

53、ed at ground level, which precludes the columns being taken right down to ground level. In that case, heavy cantilevers are required to collect the column loads from the levels above and transmit then to the central core

54、.</p><p>　　An alternative approach is to introduce a roof truss in either prestressed concrete or steel construction, at the top of the core. The floor slabs may then be supported between the core and a syst

55、em of steel hangers suspended from the roof truss. The system has the architectural advantage of lightness of façade, and can simplify construction on a congested city site. The core may be slipformed, and the floor

56、 slabs cast on site and simply hoisted into position. However, there is the inherent stru</p><p>　　A further increase in lateral stiffness can be achieved if the central core or shear wall system is tied to

57、the exterior columns by deep (usually story height) flexural members or trusses at the top and possibly at other intermediate levels. The effect of these connections is to create an overall framed system, which mobilizes

58、 the axial stiffness of the exterior columns to resist wind forces. The objective is to cause the structure to act more as a vertical cantilever beam, and so resist the win</p><p>　　The first reinforced conc

59、rete building to utilize this concept was the 51-story Place Victoria Building in Montreal (1964) , in which an X-shaped core is linked at four levels by story-high graders to the massive corner columns.</p><p

60、>　　As building become taller, the use of a core on its own to resist lateral forces will lead to unusually large cores, occupying too large a ratio of a given floor area, and leading to uneconomic solutions. The effic

61、iency can be increased substantially if the outer façade is replaced by a rigidly-jointed framework, which can be used to resist lateral as well as vertical forces. The outer shell then acts effectively as a closed

62、box-like structure, whose faces are formed of rigidly-jointed frame pan</p><p>　　A combination of the framed-tube concept with the shear wall-frame interaction concept yields the structural from termed the t

63、ube-in tube system, in which an exterior closely spaced column system is constrained by the floor slabs to act in collaboration with a very stiff shear core enclosing the central service area. The first design applicatio

64、n of this form of shear wall-frame interactive behaviour appears to have been in the 38-story Brunswick Building in Chicago, completed in 1962. In this ca</p><p>　　While the system is very useful in the crea

65、tion of flexible spaces in office buildings, it is less suitable for very tall apartment buildings. An alternative solution using the framed-tube concept was devised first for the 43-story De Witt Chestnut Apartment Buil

66、ding in Chicago in 1965. In this case, the exterior columns were closely spaced at 1.68m centres and, when rigidly connected to 600mm deep spandrel beams, gave rise to a relatively stiff exterior perforated tube which wa

67、s designed to res</p><p>　　The closely-spaced columns in a framed tube may pose problems in gaining across to the building at ground level, and some structural rearrangement may be necessary in that region.

68、Several columns may be run into one at regular intervals, as in the World Trade Center, or a deep girder may be provided at first-floor level to transfer column forces to more widely spaced first-floor columns.</p>

69、<p>　　The pure framed tube has the disadvantage that under bending action, a considerable degree of shear lag occurs in the faces normal to the wind, as a result of the flexibility of the spandrel beams. This has

70、the effect of increasing the stresses in the corner columns, and of reducing those in the inner columns of the normal panels, and results in a loss of efficiency in the desired pure tubular action of the structure. Warpi

71、ng of the floor slabs, and consequently deformations of interior partitio</p><p>　　One technique which has been employed to help overcome this problem is to add substantial diagonal bracing members in the pl

72、anes of the exterior frames. The exterior columns may then be more widely spaced, and the diagonals, aligned at some 45°to the vertical, serve to tie together the exterior columns and spandrel beams to form faç

73、ade trusses. Consequently, a very rigid cantilever tube is produced. The diagonals, however, pose their own special problems in the design of the curtain wall system.</p><p>　　For very tall buildings, the sh

74、ear lag effect may be greatly reduced by adding additional interior web panels across the entire width of the building in each direction to form a modular tube or bundled-tube system. The additional stiffening of the str

75、ucture produced by the interior webs increase the local stress levels at the exterior frame junction and thereby reduces substantially the nonuniformity of column forces caused by shear lag. The structure may be regarded

76、 as a set of modular tubes wh</p><p>　　The best known example of this form of construction is the 109-story, 442m high, Sears Tower in Chicago, the world’s tallest building. Completed in 1974, the basic cros

77、s-sectional shape consists of nine 22.86m square modular tubes, for an overall floor area 68.58m square, which continues up to the 50th floor. Step backs, produced by a termination of one or more of the modular tubes, th

78、en occur at floor 50, 66 and 90, creating a variety of floor configurations.</p><p>　　An alternative possibility, yielding the same general form of structural behaviour, is to use shear walls to form the int

79、erior webs of the framed tube and create an alternative form of multi-cellular construction. This approach has been adopted for the 74-story, 262m high Water Tower Place Building, Chicago (1976), the world’s tallest conc

80、rete building. The 64-story tower which rises from a 12-story base is a slender tube of cross–sectional dimensions 67×29m which is bisected by an internal tran</p><p><b>　　譯文：</b></p>

81、<p><b>　　高層建筑結(jié)構(gòu)的發(fā)展</b></p><p>　　建筑的出現(xiàn)應(yīng)該追溯到青銅器時代，伴隨著真正的城市的出現(xiàn)，房子也出現(xiàn)了兩層的。甚至是今天高層建筑與城市發(fā)展似乎有著本質(zhì)的聯(lián)系。多層建筑被認為是古羅馬的一大特征。在古羅馬，四到五層的木制建筑是很普遍的。那些在尼羅特大火災(zāi)后建成的建筑，采用新型的燒制磚塊和混凝土材料作成拱門和大量拱形圓頂結(jié)構(gòu)，取代了早期的柱和橫梁結(jié)構(gòu)。

82、</p><p>　　縱觀后來的幾個世紀，木材和石材成為應(yīng)用于建筑結(jié)構(gòu)的兩大基本材料。雖然在高于16米的建筑中木材缺乏所需的強度，而且還有著火的危險。而石材具有很高的抗壓強度和耐火能力，但是其自重大，易使下部的支撐負荷過重。這種結(jié)構(gòu)形式的限制在1891年芝加哥的16層建筑中顯得十分明顯，它要求下部的墻有2米多厚，因此它成為城市里最后一座采用承重石墻的建筑。</p><p>　　伴隨著19世

83、紀工業(yè)化發(fā)展，社會經(jīng)濟問題與美國城市對空間要求的無法滿足，對高層建筑產(chǎn)生了巨大沖擊。然而若在那個世紀中葉沒有兩大主要技術(shù)革新，即新型高強且在結(jié)構(gòu)上更有效的材料—精煉的鐵及后來的鋼材的發(fā)展，還有電梯的引入，使得垂直交通變得便利，高層建筑的增長也不可能得到支持。</p><p>　　新材料的出現(xiàn)使得輕質(zhì)框架結(jié)構(gòu)或骨架結(jié)構(gòu)得到發(fā)展，還使得建筑有了更高的高度以及更多更大的洞口。大約在1890年出現(xiàn)于芝加哥的鋼框架結(jié)構(gòu)的先

84、行者被認為是1801年建成的七層鐵框架結(jié)構(gòu)的曼徹斯特棉紡廠，再其建筑過程中當代的工字梁第一次出現(xiàn)了。水晶宮—為1851年倫敦國際匯展而建，采用了完全獨立的鐵框架，其中柱是由鑄鐵制成繁榮，而梁是由鑄鐵或精煉的鐵制的。這一設(shè)計的顯著特征之一就是大規(guī)模的運用大量技術(shù)成果，使得建筑和施工相當方便。</p><p>　　雖然第一部電梯出現(xiàn)于1851年紐約的一座酒店里，但是它在高層建筑中的潛力直到1870年用于紐約的家庭生命

85、保險大樓的建筑中才得以明顯證實。就這樣第一次使得上部樓層和下部樓層一樣成為備受歡迎的出租場所，也正因為這樣使得高層建筑在財政上要比普通建筑可行。鋼結(jié)構(gòu)設(shè)計方法和施工技術(shù)的改進，使得鋼框架結(jié)構(gòu)得以穩(wěn)步發(fā)展。當然這一發(fā)展在第一次世界大戰(zhàn)期間曾有所減慢。1909年50層的大都市塔樓在紐約建成，緊接著1913年60層高241米的伍爾沃斯大樓也竣工。美國摩天大樓的黃金時期隨著1931年帝國大廈圓滿竣工而達到頂峰。因為增建了電視天線使得102層的帝

86、國大廈由原來的381米升高到現(xiàn)在的449米。這棟建筑耗用了五萬七千噸美國建筑鋼材，將近五萬三千五百立方的混凝土，而且從設(shè)計到竣工僅用了17個月的時間。</p><p>　　雖然大約在本世紀初開始認真地采用鋼筋混凝土，但是第一次世界大戰(zhàn)末以前，它在多層建筑中似乎一直沒有被正確使用。組合材料的固有優(yōu)勢再那個時候沒有得到完全的重視；而且組合結(jié)構(gòu)早期的設(shè)計方法也只是純粹地模仿鋼結(jié)構(gòu)。最早的鋼砼建筑便是1903年建成于俄亥

87、俄州的辛辛那提的16層高的英戈爾斯大樓，直到1915年它才被稱為世界上最高的鋼砼建筑的19層高的達拉斯醫(yī)學(xué)技術(shù)大樓所替代。此后，鋼砼結(jié)構(gòu)的發(fā)展緩慢下來，時有是無，而且在帝國大廈建成的同時，西雅圖交易大廈僅僅只建到23 層高。</p><p>　　二十世紀三十年代的經(jīng)濟蕭條給摩天大樓的偉大時期劃上了一個句點，直到第二次世界大戰(zhàn)末后的一些年里，高層建筑的建造才又恢復(fù)，而且引入了新的結(jié)構(gòu)和建筑方案，然而現(xiàn)代發(fā)展產(chǎn)生的是

88、新的結(jié)構(gòu)布局、改良的材料質(zhì)量以及更好的設(shè)計技術(shù)和施工技術(shù)，而不是高度上的巨大增長。</p><p>　　設(shè)計原理在經(jīng)濟蕭條和戰(zhàn)爭中改變了。早期的高層建筑特征是具有重的結(jié)構(gòu)構(gòu)件且因為內(nèi)部隔墻平面剛度很大而非常堅硬，還有在建筑正立面上開有小面積的窗，然而當代的辦公樓卻以輕質(zhì)可拆卸隔墻、外部玻璃幕墻、更輕的各結(jié)構(gòu)部分、承重墻代替非承重填充墻為特征。采用輕質(zhì)可拆卸隔墻可以靈活的布置空間，各部分變輕是因為采用了高強混凝土和

89、鋼材，而承重墻可以同時用來分隔空間和圍繞空間。結(jié)果，大多數(shù)早期建筑物的隱蔽部分消失了，而現(xiàn)在的基礎(chǔ)結(jié)構(gòu)必須達到所許的強度和剛度，能夠承受垂直壓力和側(cè)壓力。因此在最近的三十年里高層建筑結(jié)構(gòu)框架體系發(fā)生了主要變化。</p><p>　　由于物體的重力隨物體存在而存在，傳統(tǒng)的建筑框架都被設(shè)計成為來抵抗重力荷載。這些荷載來源于水平的、垂直的各結(jié)構(gòu)部分的自重，包括了裝飾層、樓板層的荷載。這樣在設(shè)計柱和墻體結(jié)構(gòu)中就產(chǎn)生了根據(jù)

90、允許應(yīng)力范圍而設(shè)計的必需的最小的橫截面面積。</p><p>　　因此在過去的三十年里設(shè)計者門一直在嘗試發(fā)展盡可能減少成本和材料重量而同時又能滿足主要的建筑功能的結(jié)構(gòu)體系，這就需要對與水平樓板系統(tǒng)相連的柱和墻體結(jié)構(gòu)進行合理布置，從而提供一個能抵抗側(cè)向力和最小化附加高度的額外費用的經(jīng)濟方案。</p><p>　　雖然所提供的重力荷載路徑是有限的，但是仍有相當大的范圍來組織結(jié)構(gòu)體系使其盡可能有

91、效的抵抗側(cè)向力。為了抵抗垂直構(gòu)件中的軸力力矩而不是彎矩，可以通過對垂直構(gòu)件以及其與水平結(jié)構(gòu)連接部分做審慎明確的處理來實現(xiàn)。</p><p>　　總的來說，不同的結(jié)構(gòu)體系已經(jīng)形成為住宅和辦公樓兩大體系，反映在它們不同的功能需求上。然而，一些著名的建筑在修建中，故意將這兩類建筑混合在一起，試圖使垂死的市中心地區(qū)獲得新生。</p><p>　　住宅建筑的基本功能要求是為群體成員提供分割的居住單元

92、。這些居住單元還有生存、睡覺、做飯和廁所的普通功能要求。這就必須要用隔墻分割開來，而且隔墻還要具有在各層居住單元間有防火和隔聲的功能。</p><p>　　因為永久性隔墻的出現(xiàn)，允許柱的設(shè)計與建筑設(shè)計相符，框架結(jié)構(gòu)可能會有效地被住宅建筑采用。然而，這些結(jié)構(gòu)的穩(wěn)定將處決于連接處抵抗側(cè)向力的剛度，而且當結(jié)構(gòu)達到20~25層時會變得不夠經(jīng)濟，因為依據(jù)結(jié)構(gòu)的整體尺寸，風(fēng)力將在設(shè)計中起控制作用，要達到所需的剛度也就會越來越

93、困難。自從二十世紀四十年代末引入了剪力墻——要么獨立存在，要么以核心組裝的形式存在。它已經(jīng)廣泛的被采用，用來作為傳統(tǒng)框架結(jié)構(gòu)的附加剛度部分。</p><p>　　為了在住宅間提供足夠的防火、隔音功能，磚和砌塊砌筑的填充嵌板被引入到框架結(jié)構(gòu)中，雖然存在可用來評估這些填充板材對框架強度和剛度影響的技術(shù)，但是依據(jù)設(shè)計者的想法，擔心這些板材在將來末一天因功能改變要么被去掉要么就是被打孔，還有填充嵌板與周圍框架達到緊密地適

94、應(yīng)的困難性，所以這些嵌板都被認為是不承重的。因此后來的趨勢都是利用墻體來在結(jié)構(gòu)物中劃分空間，并省去了相對較重的不能用于承受荷載的填充墻。由此導(dǎo)致了剪力墻建筑物的出現(xiàn)，，在該類建筑中結(jié)構(gòu)墻用來劃分和圍隔空間，同時也承受豎向和水平荷載。這些墻一般都是預(yù)制的大塊嵌板或者是現(xiàn)場澆注的鋼筋混凝土結(jié)構(gòu)，但是混凝土砌塊結(jié)構(gòu)和磚結(jié)構(gòu)也被采用，與預(yù)制樓板結(jié)構(gòu)相似。因為功能設(shè)計中要求住宅間有許多隔墻，所以也就頻繁地發(fā)現(xiàn)防火隔音所需的最小厚度也將要充分滿足結(jié)

95、構(gòu)需求。</p><p>　　這種建筑形式的功能要求導(dǎo)致了厚板塊橫墻建筑和尖頭塊建筑的出現(xiàn)；前者中，居住者書評方向的活動就是靠在建筑物中間的沿縱向的走廊實現(xiàn)的，而走廊兩邊便是一套套公寓房間；后者中公寓房間是圍繞著垂直交通部分——電梯和樓梯而布局的。在每種建筑中，基本結(jié)構(gòu)都是由垂直的剪力墻體系組成，而這些剪力墻又通過樓板或是寬約門窗、走廊洞口的橫梁聯(lián)系起來，形成一個穩(wěn)定的結(jié)構(gòu)。結(jié)構(gòu)的核心部分是由集在一起的墻體組成。

96、這些墻體沿著它們的垂直邊緣連接起來，形成一些全開或半開的圍繞電梯井和樓梯間的盒子似的部分。結(jié)構(gòu)的這些核心在建筑物中起著加強點的作用，在承擔側(cè)向力方面起著主要作用。</p><p>　　在設(shè)計中，剪力墻必須有足夠剛度來符合強制的側(cè)移標準，且除此之外，還應(yīng)該布置合理使得由風(fēng)力引起的拉應(yīng)力小于建筑物自重引起的壓應(yīng)力。這種能提高結(jié)構(gòu)功效的墻體布局可以通過圖19.3簡單描述；它由一系列的橫墻和兩道穿越建筑寬度方向的側(cè)墻組成

97、。我們作一個有理由的近似處理認為：每道橫墻承受了圖中陰影部分面積的荷載，如果橫墻與縱墻一樣厚，這樣橫墻上的壓應(yīng)力將會是側(cè)墻上的兩倍，然而如果所有的墻在風(fēng)荷載作用下發(fā)生的側(cè)移都相等，作為鋼筋混凝土樓板平面內(nèi)剛度很大的結(jié)果就是，每道墻的彎矩和聯(lián)系應(yīng)力將分別與它的截面抗彎和剪切模量成比例。因此側(cè)墻上的最大拉應(yīng)力大約是橫墻撒謊能夠的4倍，側(cè)墻將由拉應(yīng)力控制。一種更有效的結(jié)構(gòu)可以通過將每道側(cè)墻分開為兩個單元，或是為了形成一種建筑效果而使它們有所錯