土木工程專業(yè)英語(yǔ)Chapter 8Bridge Engineering

1、Chapter 8 Bridge Engineering Bridges are great symbols of mankinds conquest of space. It is a structure that spans obstacles, such as rivers, lakes, or gorges, to provide a roadway for traffic. By far the majority of bridges are designed to carry automobile or railroad traffic, but some are intended

2、 for pedestrians only. Bridges also support pipes, troughs, or other conduits that transport materials, such as an oil pipeline or a water aqueduct.Section A Bridges（橋梁工程 ）（橋梁 ） 橋梁是人類征服空間的偉大象征，它跨越了許多障礙，比如河流、湖泊、峽谷，為交通提供了道路。到目前為止，大多數(shù)橋梁的功能是承擔(dān)汽車和鐵路交通，但也有一些為行人所用，另外，橋梁也支持管道、槽或其他運(yùn)輸材料的渠道，比如輸油管或者水渡槽等。 Humans

3、 have been constructing bridges since ancient times. For a few thousand years the classical form in bridge design has been the vault or arch. This structure, because of its inherent contour, utilized masonry as its material. The use of concrete as a building material, however, was not considered unt

4、il late in the nineteen century. The first application of reinforced concrete to bridge structures waspioneered by Hennebique. 人類從遠(yuǎn)古時(shí)期就已經(jīng)開(kāi)始修建橋梁了。近千年來(lái)拱橋一直是橋梁的傳統(tǒng)形式，由于其固有的外形，這類結(jié)構(gòu)可以利用磚石作為它的材料。直到19世紀(jì)后期，混凝土才被用作建筑材料。第一次把鋼筋混凝土應(yīng)用于橋梁結(jié)構(gòu)的是Hemmebique。 同一時(shí)期Jackson and Doehring提出了預(yù)應(yīng)力混凝土的概念，但是由于混凝土收縮和徐變?cè)斐傻母哳A(yù)應(yīng)力損失使得它

5、的應(yīng)用并不成功。 In the same period prestressed concrete concepts were being formulated by Jackson and Doehring. There application was not successful because of the high losses in prestress caused by shrinkage and creep of the concrete. It was not until 1926-1928 when Freyssinet was able to control these lo

6、sses with high-strength steel that prestressing was considered feasible. 直到1926-1928年Freyssinet采用高強(qiáng)度鋼筋有效的控制了預(yù)應(yīng)力損失，預(yù)應(yīng)力結(jié)構(gòu)才被認(rèn)為是可行的。 Prestressed concrete was widely use for bridges after about 1950. Steel became more useful for bridges with the development of stronger and more corrosion-resistant alloys

7、. Aluminum alloys, which were used in bridges as early as 1933, greatly reduce the dead weight of the bridge, but they are not widely used because they are relatively expensive. 預(yù)應(yīng)力混凝土被廣泛用于橋梁結(jié)構(gòu)是在1950年以后了。隨著更大強(qiáng)度以及更加抗銹蝕合金的發(fā)展，鋼材在橋梁上的應(yīng)用也更加廣泛了。鋁合金早在1933年就應(yīng)用于橋梁結(jié)構(gòu)了，它極大的降低了橋梁的自重，但是由于造價(jià)昂貴并沒(méi)有被廣泛使用。 The princi

8、pal portions of a bridge may be said to be the “superstructure” and “substructure” (sbstrkt n.下部結(jié)構(gòu)) . This division is used here simply for convenience, sine in many bridges there is no clear dividing line between the two. Bridges may also be classed as “deck” (dek n.橋面，甲板，覆蓋物；vt.裝飾，修飾，打扮) or “throu

9、gh” types. In the deck type (上承式) of bridge, the roadway is above the supporting structure, that is, the load carrying elements of the superstructure are below the roadway. 橋梁的主要結(jié)構(gòu)被稱為上部結(jié)構(gòu)和下部結(jié)構(gòu)，這種劃分方法用在這里只是為了方便起見(jiàn)，然而，在許多橋梁中這兩者的界限是很不明顯的。橋梁也可以分為上承式和下承式。上承式橋梁的車道位于支撐結(jié)構(gòu)之上，也就是說(shuō)，承擔(dān)荷載的上部結(jié)構(gòu)是位于道路以下的。 而下承式橋梁的道路是

10、橫穿上部結(jié)構(gòu)的。上承式結(jié)構(gòu)是居于主導(dǎo)地位的。 In the through type(下承式) of bridge, the roadway passes between the elements of the superstructure. Deck structures predominate(pridmineit vi.占支配地位；vt.在中占優(yōu)勢(shì)) ，they have a clean appearance, provide the motorist with a better view of the surrounding area, and are easier to widen

11、if future traffic requires it.因?yàn)樗庑魏?jiǎn)潔，能夠?yàn)槠囻{駛員提供更好的視線范圍，而且如果將來(lái)由于交通要求需要拓寬道路也比較容易實(shí)現(xiàn)。 每一個(gè)中長(zhǎng)跨橋梁的設(shè)計(jì)師都試圖設(shè)計(jì)出一個(gè)結(jié)構(gòu)可以最大程度滿足那些特殊位置下的條件.以下幾段的內(nèi)容對(duì)橋梁一般的類型進(jìn)行簡(jiǎn)要的介紹： The designer of each medium and long-span bridge(大跨徑橋) tries to devise a structure that is best suited to the conditions encountered at that particular

12、location. The result is an almost bewildering biwildri adj. (情況)讓人困惑的, 令人費(fèi)解的 ) variety of structures that differ either in basic design principle or in design details. General categories of bridges are briefly described in the following paragraphs:其結(jié)果往往是不同的設(shè)計(jì)師會(huì)設(shè)計(jì)出不同的結(jié)構(gòu)類型，無(wú)論是就基本的設(shè)計(jì)原則還是設(shè)計(jì)細(xì)節(jié)而言。Girder b

13、ridges(梁橋) A girder:d n.梁,鋼桁的支架，縱梁，主梁) bridge is perhaps the most common and most basic bridge. A log or a piece of other material across a creek is an example of a girder bridge in its simplest form. That piece of material called a girder or beam rests directly on the ground on each side or is supp

14、orted on heavy foundations known as piers (pi n.（橋）墩, 支柱) . Girder bridges come in two basic varieties: plate and box girders. Simple or continuous beam-type bridges can be made of timber(timb n.木材，木料，樹(shù)木, 橫梁) , steel, concrete, prestressed concrete or other materials. 梁橋 梁橋或許是最常見(jiàn)和最基本的橋梁。橫跨小河的一塊木頭或者一

15、根其他材料都是最簡(jiǎn)單形式的梁橋。這段材料就被稱為梁它直接擱置梁橋在水域的兩側(cè)，或者支撐在很重的基礎(chǔ)之上也就是眾所周知的柱。包括兩個(gè)基本類型：板梁和箱梁。簡(jiǎn)支梁橋或者連續(xù)梁橋可以由木材、鋼材、混凝土、預(yù)應(yīng)力混凝土或其他材料所構(gòu)成。 預(yù)制裝配式預(yù)應(yīng)力梁橋是常見(jiàn)的一類橋型，可以修建成為立交橋或者跨河橋。這類橋50年代后廣泛應(yīng)用。 The precast, prestressed beam type is a popular bridge type. These bridges can be found both as overpasses and as bridges. This type of b

16、ridge became popular in the 1950s. Prestress indicates that the reinforcing is stressed before loading, thereby placing the entire concrete beam section in compression or at a low value tension stress. Since concrete is strong in compression and relatively weak in tension, this procedure creates a m

17、ore effective concrete section.預(yù)應(yīng)力就是指在荷載施加之前給予混凝土的預(yù)壓力，從而使整個(gè)混凝土梁截面處于受壓狀態(tài)或者低拉應(yīng)力狀態(tài)。因?yàn)榛炷量箟簭?qiáng)度較高而抗拉很弱，這種操作產(chǎn)生了更加有效的混凝土截面。 Arch bridges(拱橋) A strong point in favor of(贊成，支持)arch bridges in their pleasing appearance and aesthetic elegance. Arch(:t n.拱, 拱門(mén)，拱形物；vt. & vi. (使)彎成拱形) bridges can be made of bricks

18、 or stone blocks that are held together by the compressive force characteristic of the arch. because tensile strength is not necessarily required for arch construction. Reinforced concrete and steel arches are altogether much lighter structures. The structure consists basically of the arch, the deck

19、 and usually some supports from the arch to the deck.拱橋 拱橋的優(yōu)點(diǎn)就是造型美觀優(yōu)雅。拱橋可以用磚石等塊材修建，由于它們受到壓力的作用而結(jié)合得很緊密。因?yàn)閷?duì)于拱橋抗拉強(qiáng)度幾乎是不需要的。鋼筋混凝土拱橋和鋼拱橋都是非常輕的結(jié)構(gòu)類型。結(jié)構(gòu)的基本組成就是拱、橋面和一些位于拱與橋面之間的支撐構(gòu)件。Cantilever bridges(懸臂橋) To solve the problem of increasing the span distance, other alternatives to beam and arch bridges includ

20、ed suspension (sspenn n.懸掛，懸浮，吊，懸架) and cantilever (kntili:v n.懸臂(梁), 伸臂, 突梁) bridges. Among the largest cantilever bridges in the United States is the Commodore John Barry Bridge.懸臂橋 為了解決持續(xù)增加的跨徑問(wèn)題，除了梁橋和拱橋外，可以選擇的有懸臂橋和懸索橋。在美國(guó)跨度最大的懸臂橋是Commodore John Barry 橋。 A cantilever bridge is a bridge built using

21、 cantilevers, a cantilever is a structure or beam that is unsupported at one end but supported at the other, like diving boards. When anchored firmly, a cantilever is a very strong structure. It consists of three parts: the outer beams, the cantilevers, and the central beam. This configuration made

22、longer spans possible and wider clearance beneath 懸臂橋是采用了懸臂結(jié)構(gòu)的橋型，懸臂是一端支撐而另一端沒(méi)有支撐的結(jié)構(gòu)，就像跳水板。如果錨固牢固懸臂是強(qiáng)度很高的一種結(jié)構(gòu)。它由三部分組成：邊梁，懸臂，中梁。這種構(gòu)造可以獲得更長(zhǎng)的跨徑和更寬的凈空。 For small footbridges, the cantilevers may be simple beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built f

23、rom structural steel, or box- girders(箱形梁) built from prestressed concrete. 對(duì)于小型人行橋，懸臂是一種簡(jiǎn)單的梁型。然而，設(shè)計(jì)用于公路或鐵路交通的大型懸臂橋往往采用鋼桁架結(jié)構(gòu)或者是預(yù)應(yīng)力混凝土箱梁結(jié)構(gòu)。 The cantilever bridge was a popular type of bridge in the first half of the twentieth century, but at present, some commentators believe that the cable-stayed br

24、idge(斜拉橋) will replace it for comparable spanning distances. 在20世紀(jì)前半段時(shí)期，懸臂梁橋是一種非常普遍的橋梁形式。但目前，一些評(píng)論家認(rèn)為，斜拉橋?qū)⒂捎诟蟮目缭侥芰Χ〈鷳冶蹣颉?Suspension bridges(懸索橋) Suspension bridges are used for very long spans or for shorter spans where intermediate piers cannot be built. Of all the bridge types in use today, the s

25、uspension bridge allows for the longest spans. The principal structural elements of a suspension bridge are: flexible main cables(柔性主纜), towers, anchorages, hangers, deck and stiffening(stifn vt. & vi.變硬，加強(qiáng)，加勁) girder. Some primitive examples of suspension bridges use vines(vain n.藤本植物, 藤) and ropes

26、 for cables. 懸索橋應(yīng)用于那些無(wú)法修筑中間墩臺(tái)的大跨徑或稍短一些跨徑的橋梁結(jié)構(gòu)。在當(dāng)今使用的所有橋梁形式中，懸索橋具有最大的跨越能力。懸索橋主要的結(jié)構(gòu)組成包括：柔性主纜、塔架、錨錠、吊桿、橋面板和加勁梁。一些原始的懸索橋使用藤或繩索作為纜索。 The portion of the bridge structure below the level of the bearing and above the foundation is generally referred to as substructure. Substructure of bridge fall into two d

27、istinct categories: end supports(端部支撐)and intermediate supports(中間支撐). The end supports are normally described as the “abutments” (btmnt n.橋臺(tái)，橋墩，橋基) , whilst the general term for the intermediate supports of a multi-span bridge(多跨橋) is the “piers”. The abutments and piers are usually constructed fro

28、m in situ concrete, but precast sections can be employed to speed up the construction process.Section B Substructure of Bridge（橋梁的下部結(jié)構(gòu) ） 橋梁支座以下基礎(chǔ)以上的結(jié)構(gòu)通常稱其為下部結(jié)構(gòu)。下部結(jié)構(gòu)可以分為兩個(gè)不同的類別：端部支撐和中間支撐。端部支撐通常稱為橋臺(tái)，而對(duì)于多跨橋的中間支撐一般稱為橋墩。橋臺(tái)和橋墩通常是現(xiàn)場(chǎng)混凝土澆注而成，但是預(yù)制構(gòu)件的應(yīng)用可以加快施工進(jìn)度。Piers Special attention must often be given to th

29、e design of the bridge piers, since heavy loads may be imposed on them by currents, and floating ice and debris.橋墩設(shè)計(jì)橋墩時(shí)必須特別注意，因?yàn)闃蚨湛赡芤袚?dān)由水流、浮冰或其他漂浮物產(chǎn)生的重荷。 The general shape and features of a pier depend to a large extent on the type, size and dimensions(dimenn n.尺寸，度量，量綱)of the superstructure and als

30、o on the environment in which the pier is located. Piers can be solid, cellular(seljul adj.多孔的，格狀的) , trestle tresl n.支架，棧橋，高架橋 or hammerhead hmhed n.倒梯形，錘頭 types. 橋墩的形狀和形式在很大程度上取決于上部結(jié)構(gòu)的型式、尺寸和規(guī)格以及橋墩所處的周邊的環(huán)境。橋墩可以是實(shí)心式、空心式、排架式，倒梯形。 Solid and cellular piers for river bridges should be provided with semi

31、circular (semis:kjul adj.半圓的) cut waters to facilitate streamlined flow and to reduce scour. Other designs such as reinforce concrete framed type have also been used. Solid piers are of masonry or mass concrete. It is permissible to use stone masonry for the exposed portions and to fill the interior

32、 with lean concrete(素混凝土 ). This would save expenses on shuttering(tri n.模板（殼）) and would also enhance appearance. Cellular, trestle and hammerhead types use reinforced concrete. 跨河橋梁的實(shí)心橋墩或空心橋墩應(yīng)當(dāng)提供半削減水域，以適應(yīng)水流的流向和減輕沖刷。其它設(shè)計(jì)，如鋼筋混凝土框架形式也有應(yīng)用。實(shí)心橋墩一般由圬工材料或大體積混凝土構(gòu)成。對(duì)于暴露在外的部分容許使用石砌圬工結(jié)構(gòu)，內(nèi)部填注素混凝土。這樣可以減少利用模板并且外

33、表面也得以加強(qiáng)?？招氖?、排架式和倒梯形橋墩采用鋼筋混凝土。 Vertical and horizontal loads transmitted from the superstructure disperse rapidly from the top of a pier. Hence, the overall design of a pier is normally conducted on a meter strip basis, assuming a uniform distribution(均勻分布) of axial and bending effects. The degree of

34、 bending will depend upon the articulation of the deck and the length of the superstructure. 從上部結(jié)構(gòu)傳遞下來(lái)的垂直荷載和水平荷載在橋墩頂部迅速擴(kuò)散。因此，通常橋墩的整體設(shè)計(jì)是取單元寬度進(jìn)行的，并且假定軸向力和撓度的影響都是均勻分布的。在恒載作用下，混凝土橋墩中軸向壓應(yīng)力的大小通常在的范圍內(nèi)，并且在最不利活載條件的作用下，其值一般彎曲的程度取決于橋面板的聯(lián)結(jié)情況和上部結(jié)構(gòu)的長(zhǎng)度。也不會(huì)超過(guò)2N/mm2 。 Reinforced concrete framed type of piers has bee

35、n used in recent years. The main advantage in their use is due to reduced effective span lengths for girders on either side of the centre line of the pier leading to economy in the cost of superstructure. 在最近幾年，鋼筋混凝土排架式橋墩已經(jīng)普遍應(yīng)用。它的主要優(yōu)勢(shì)就是可以降低在橋墩中心線兩側(cè)梁的跨徑，從而提高了上部結(jié)構(gòu)造價(jià)的經(jīng)濟(jì)性。 Individual concrete columns ar

36、e often used to support footbridges (futbrid n.人行橋) and bridge decks with high skew or greater height than the minimum headroom clearance(凈空高度) . Columns may be vertical, inclined or even curved in shape to produce greater aesthetic appeal. A column section is normally required to resist bi-axial (b

37、aiksil adj.雙軸的，雙向的)bending and significant axial loading. Concrete columns are therefore often circular or square, but hexagonal( heksnl adj.六角形的，六邊形的) and octagonal ktnl adj.八邊（角）形的；n.六邊（角）形 sections are also common. 單個(gè)混凝土墩柱常用來(lái)支撐人行橋和橋面板，這些橋面板斜度更大，高度也比最小凈空高度高很多。為了使結(jié)構(gòu)更加美觀，柱可以是垂直的、傾斜的甚至是彎曲的。柱截面通常要求可以抵

38、抗雙向彎曲和很大的軸向荷載。因此混凝土柱通常為圓形或方形，六角形和八角形截面也比較普遍。Abutments (橋臺(tái)） An abutment serves two principal functions. It is the substructure which supports one terminus（t:mins n.終點(diǎn)站, 終點(diǎn)，邊界, 界限, 極限） of the superstructure of a bridge and, at some time, laterally supports the embankment （imbkmnt n.路堤，岸堤，堤） which serv

39、es as an approach to the bridge. For a river bridge, the abutment also protects the embankment from scour of the stream. Bridge abutments can be made of masonry, plain concrete（素混凝土） or reinforced concrete. Hence, an abutment combines the functions of a pier and a retaining wall. 橋臺(tái)有兩個(gè)主要功能：它是下部結(jié)構(gòu)，支撐

40、橋梁上部結(jié)構(gòu)的一個(gè)端部，有時(shí)它也為緊接橋梁的路堤提供橫向支撐。對(duì)于跨河橋梁，橋臺(tái)還要保護(hù)路堤免受水流沖刷。橋臺(tái)可以由圬工材料、素混凝土或鋼筋混凝土構(gòu)成。因此，橋臺(tái)綜合了橋墩和擋土墻的功能。 One of the most common types of abutment is the gravity abutments with wing walls. It consists of a central pier supporting the bridge seat, and two wing walls to retain the fill. All three elements rest o

41、n a single footing. If the wing walls are at right angles to the pier, the structure is known as a U abutment. The wing walls of a U abutment are sometimes tied together to reduce their tendency to overturn. 角，就是眾所周知的U形橋臺(tái)，其側(cè)墻有時(shí)綁定在一起以防止結(jié)構(gòu)傾覆。最常見(jiàn)的橋臺(tái)形式是帶有兩個(gè)側(cè)墻的重力式橋臺(tái)。它由一個(gè)支撐橋梁支座的中心橋墩和兩側(cè)起擋土作用的側(cè)墻組成。所有這三個(gè)部分都位

42、于同一個(gè)基礎(chǔ)之上。如果側(cè)墻與橋墩呈直 The spill-through(穿通式的) or open abutment(敞開(kāi)式橋臺(tái)) is also widely used. It consists of two or more vertical columns carrying a beam that supports the bridge seat. The fill extends on its natural slope from the bottom of the beam through the openings between the columns. In its extrem

43、e form a spill-through abutment is no more than a row of piles driven through the fill and supporting a bridge seat. Another common variation is a simple pier with small wings near the top. The fill in this case spills around the abutment. 穿通式或敞開(kāi)式橋臺(tái)的應(yīng)用也比較普遍。它是由兩個(gè)或更多的支撐橋主梁的豎直柱所構(gòu)成。填注材料按照其自然坡度從梁底部通過(guò)柱之間

44、的空隙。它的極端形式穿通式橋臺(tái)只是一排從填注材料中延伸出的支撐橋梁支座的樁。另外一種常見(jiàn)的形式就是簡(jiǎn)單的一個(gè)在頂部帶有小型翼墻的橋墩，在這種情況下填注材料位于橋臺(tái)周邊。The design of an abutment consists in assuming preliminary dimensions depending on the type of the superstructure and foundation, and checking the stresses at the sill(sil n.底梁，底座，基礎(chǔ)，底面) level. The front face of the

45、breast wall should have a batter(bt n.傾斜，坡度，傾斜度)of not less than 1 in 25, preferably at 1 in 12. The rear batter is adjusted to get the width required to restrict the net pressures within the prescribed limits. 橋臺(tái)的設(shè)計(jì)包括：根據(jù)上部結(jié)構(gòu)和基礎(chǔ)的形式擬定初步尺寸，驗(yàn)算地基土壓應(yīng)力。胸墻前側(cè)應(yīng)該有不小于1/25的坡度，最背部的坡度要進(jìn)行適當(dāng)?shù)恼{(diào)整，以獲取所需的好是在1/12左右。寬度來(lái)限

46、制靜壓力在規(guī)定的范圍內(nèi)。 A bridge abutment may fail in several ways as below, and the final design should be checked to avoid these failures. The breast wall may fail by tensile cracks, crushing or shear. The wall may tilt(tilt n.傾斜，車篷；vt. & vi. (使)傾斜，斜置 ) forward due to excessive overturning moment(傾覆力矩) due t

47、o earth pressure. The wall may slide forward due to earth pressure if the vertical forces are inadequate. Though the wall may be structurally strong, failures may occur along a curved surface by rupture(rpt n.破裂，斷裂；vt. & vi. (使)破裂) of the soil due to inadequate shear resistance(抗剪力) . 如果垂直壓力不足，在土壓力的

48、作用下墻體會(huì)產(chǎn)生滑移。即使墻體強(qiáng)度比較高，也有可能因?yàn)橥馏w開(kāi)裂造成抗剪不足導(dǎo)致墻體彎曲變形而失效。橋臺(tái)可能在以下幾種情況下失效，而最終的設(shè)計(jì)必須保證前墻可能由于張拉裂縫、沖擊或是剪切能夠避免這些失效。而發(fā)生破壞。由于地震引起的過(guò)度的傾覆彎矩會(huì)造成墻體傾斜。 The main structure of the Three Gorges Project(三峽工程) consists of the water impounding dam(蓄水大壩) , flood releasing installations(泄洪設(shè)施) , power plants, and navigation facili

49、ties. The dam is a concrete gravity type with a max height of 175185m and total 1ength of 2,5002,800m. The spillway(spilwei n.溢洪道, 泄洪道) section is built in the middle of the river channel. There are two power plants at the toe of the dam. The navigation facilities are arranged on the left bank. 在大壩底

50、有兩個(gè)電站，導(dǎo)航設(shè)施安排在左岸。三峽工程的主體結(jié)構(gòu)的組成包括蓄水大壩，泄洪設(shè)施，發(fā)電站，和導(dǎo)航設(shè)施.大壩是一個(gè)混凝土重力壩，最大高度175 -180米和總長(zhǎng)2500 2800米，溢洪道部分建立在河道的中間Exercises . Fill in the blanks with the information given in the text.1. Gravity abutment consists of a central _ supporting the bridge seat, and two _ walls to retain the fill.2. Piers can be solid

51、, _, trestle or _ types.3. Substructure of bridge fall into two distinct categories: _ supports and _ supports.3. In some recent designs, concrete hinges have been introduced between the top of columns and the _ cap in order to avoid moments being transferred from deck to the _.pier wing cellular hammerhead end intermedia