外文文獻翻譯 中英文對照 道路畢業(yè)設計 交通系統(tǒng)

1、 交通系統(tǒng)交通運輸一直是土木工程最重要的一個方面。古羅馬工程師的巨大成就之一就是公路系統(tǒng)，它使羅馬與帝國的各個省之間的快速交通成為可能。在工程方面的第一所培訓學校就是橋梁和公路學校，它于 1747 年創(chuàng)建于法國。而在英國，一位道路建筑家，托馬斯泰爾福特于 1820 年擔任了土木工程學會的第一任主席?，F(xiàn)代公路仍然根據(jù) 18 世紀及 19 世紀初法國人皮埃爾特埃薩凱，英國人泰爾福特，以及蘇格蘭人約翰 L馬克當所制定的原則進行建造。這些人設計出了最初的現(xiàn)代道路，這種道路具有堅實的墊層，基礎就建在墊層的上面。他們設計的道路還具有排水良好而且不滲水的磨耗層，即直接承受車輛交通磨耗的表層。特埃薩凱和泰爾福

2、特均采用較厚的石頭基礎，在其上面鋪筑由較小碎石組成的基層和由更小的石頭組成的磨耗層。他們的道路還微微隆起成曲線，形成路拱和反拱以便使雨水流走。馬克當認識到當土壤被夯實或壓緊之后，只要保證干燥，其本身就可承受道路的重量，因而他能夠通過在壓實的墊層上鋪碎石基層來省掉建造石頭基礎所需要的昂貴費用。當時車輛的鐵質(zhì)車輪把表層石頭碾壓成連續(xù)的，較為平整的，更加不透水的表面。早 19 世紀，貨車和客車都采用鐵或鋼制車輪，這種道路是適用的。當汽車在 20 世紀初出現(xiàn)之后，其橡膠輪胎毀壞了這種平整的路面。因此，就采用焦油或瀝青摻拌碎石，使路面表層更堅固的黏合一起?，F(xiàn)在，遍布全世界的數(shù)百萬公里的道路采用這種路面。

3、在 20 世紀，道路建設基本上僅在兩方面進行了改進。第一種改進是采用混凝土作為磨耗層。另一種改進則是交通工程，即設計高速的大交通量的、造價經(jīng)濟并且對于車輛和旅客都安全的公路。交通工程已建成了現(xiàn)代高速公路，這種公路具有限定的入口和最安全的管理。老式道路常用的拐角形交叉已不使用，而采用互通式立體交叉或其他更為復雜的設計。現(xiàn)代高速公路通常設有專門的車道，在那里當車輛要駛出公路時可減速駛?cè)霑r可加速。應該盡量減少急彎或陡坡，以使能在不減速的情況下連續(xù)行駛。由于單調(diào)已被實踐證明是對安全有害的，故交通工程甚至要包括道路兩旁景觀的設計工作。- 1 - 當開始建設一條新的公路時，被稱為推土機的大型運土機械要沿著

4、指定路線平整土地。平土和填土的運土量都要預先計算出來。不論在哪里，都要盡可能使移除土壤的挖方量等于就近所需的填方量。遠距離運土是很昂貴的，而經(jīng)濟效益是工程師工作的一個關鍵方面。在運完土方并根據(jù)道路設計的橫斷面定形之后，其他機械就為墊層做準備。其中最主要的一種機械很可能是振動壓路機，它被用來壓實地面，直至地面能承受將要壓在其上的基層及磨耗層傳來的重量。但是在許多情況下，必須用其他材料與土拌和而使土壤穩(wěn)定。這種材料可以是瀝青，也可以是混凝土漿或者其他物質(zhì)。接著是基層，它或者是碎石，或者是用一種稀薄的混凝土鋪成，然后才鋪磨耗層。磨耗層可以是一層瀝青，也可以是一排排鋼筋混凝土板。混凝土路面必須分段鋪設

5、，每段之間留有膨脹縫，使其能在不同氣候條件下膨脹和收縮。鋪鋼筋混凝土磨耗層的一種方法是在澆筑一部份混凝土之后，再鋪鋼筋，鋼筋通常為格柵狀或網(wǎng)柵狀。為了保證良好的粘結，必須在澆筑完底部的后 20 分鐘之內(nèi)澆完頂層。另一種方法是先澆筑全部所需厚度的混凝土，然后再將鋼筋網(wǎng)按預定的標高壓到混凝土當中。一組總稱為混凝土鋪路機組的機器通常能以每分鐘四分之三米的速度完成所有的工序。一種新的，稱為滑膜鋪路機的單機，除了不能鋪設鋼筋網(wǎng)外，可以完成混凝土鋪路機組所能完成的所有工作。已經(jīng)研究出了一種新技術，就是先把鋼筋網(wǎng)安放就位，然后使機械通過并在鋼筋周圍澆筑混凝土。滑膜鋪路機能以每分鐘大約兩米的速度進行工作。飛機

6、場跑道的施工也按類似的步驟進行，只不過跑道用的水泥板比公路用的要寬的多。飛機場必須設計的不僅能夠承受大型噴氣飛機的巨大荷載，而且還要能夠承受發(fā)動機噴出的強烈的熱流。飛機的沖擊系數(shù)也不比汽車的大。公路與飛機場跑道的區(qū)別在于尺寸和強度，而不是設計和施工的方法。如果說大型混凝土高速公路是本世紀的交通奇跡的話，那么鐵路就是 19 世紀的交通奇跡。在 1829 發(fā)明蒸汽機車以前，人們也知道運用鐵路運輸。不過，當時鐵路線路的長度只限于馬或者其他動物能夠拖著重物進行短距離運輸?shù)姆秶鷥?nèi)。這種鐵路大部分是和采礦作業(yè)一起興建起來的。在蒸汽機車成- 2 - 為使用機器之后，建造鐵路的熱潮迅速興起，使鐵路網(wǎng)絡擴展到世

7、界各地。到 1920 年，鐵路建設的鼎盛時期已經(jīng)基本結束。隨著汽車的使用日益廣泛，重點就轉(zhuǎn)移到公路建設上。除了有限的改進，諸如電氣化等鐵路已不再被人們重視。不過，現(xiàn)在人們對鐵路又有了新的認識。例如，日本人最近開通了從東京到大阪的新干線，其高速列車在正常運行時，平均速度為每小時 166公里，并且達到了最高速度為每小時 210 公里。甚至在許多鐵路都處于不景氣狀況的美國，特別是在其東部地區(qū)，對提供良好服務的興趣也正在增長。不僅在美國，而且在其他國家的人們對建立城市快速交通系統(tǒng)也呈現(xiàn)的較大的興趣。附件 2：外文原文（復印件）Transportation Systems- 3 - Transporta

8、tion has always been one of the most important aspects of civilengineering .one of the great accomplishments of the Roman engineers was thehighway system that made rapid communication possible between Rome and theprovinces of the empire. The first school that offered training specifically inengineer

9、ing was the School of Bridges and Highways, established in France in 1747.And in England, Thomas Telford, a roadbuilder, became the first president of theInstitution of Civil Engineers in 1820.Modern highways are still built according to the principles laid down in the eighteenthand early nineteenth

10、 cenruries by a Frenchman, Pierre Tresaguet, the EnglishmanTelford, and a Scot, John L. McAdam. These men designed the first modern roads thathad a firm footing, the surface on which the foundstion rested. Their roads alsoincluded good drainage and a wearing surface-the top levelthat directly receiv

11、es thewear of traffic-that could not be penetratated by water. Both Tresaguet and Telfordused a heavy foundation of stones, on top of which a base course of lighter crushedstones and a wearing surface of still smaller stones were built up. Their roads werealso slightly curved in a crown or camber so

12、 that the water would run off. McAdamrealized that the soil utself could bear the weight of the road when it was compactedor pressed down, aslong as it remained dry. He wasable therefore to eliminate theheavy cost of the stone foundation by laying a base course of crushed stone on top ofa compacted

13、footing. The iron wheels of the carriages of his day ground the stones ofthe top level into a continually smoother and more watertight surface.These roads were adequate during the nineteenth century when wagons and carriageshad tires made of iron or steel. When the automobile appeared at the beginng

14、 of thetwentieth century, however, its rubber tires broke up the smooth surfaces.Therefore,the top layer was bound together more firmly by mixing the crushed rockwith tar or asphalt. Millions of kilometers of roads throughout the world today havethis kind of surface.Basically, roadbuilding has impro

15、ved in only two ways in the twentieeh century. The- 4 - first improvement involves the use of concrete for the wearing surface. The other istraffic engineering, the design of highways for high-speed, heavy-volume traffic,highways thathat are economical to build and safe for vehicles and their passen

16、gers.Traffic engineering has produced the modern express highway that has only limitedaccess and maximum safety controls. The angular intersections common on olderroads have been eliminated in favor of interchanges or others with even morecomplicated designs. Modern express highways usually have spe

17、cial lanes wheretraffic can either slow down before exiting or speed up upon entering.Extreme curvesor steep slopes are minimiced so that the traffic can continue to move without slowing down. Since monotony has proved to be a safety hacard, tiaffic engineering evenincludes the landscaping of the bo

18、rders of the road.When construction on a new highway begins, huge earthmoving machines calledbulldocers level the ground along the designated route. The amount of earth to bemoved, both in leveling and filling , has been previously calculated. Whereverpossible, the amount in a cat where earth is bei

19、ng removed shoule be equlal to theamount needed for a nearby fill. Moving earth form a distant point is extremelyexpensive, and economy is a critical aspect of an engineers work.After the earth has been moved and shaped according to the design of the road, othermachines prepare the footing . The mos

20、t important of these is probably a vibratingroller, which compacts the earth until it can bear the weight of the base course angwearing surface that will rest on it. In many cases, however, the soil must bestabilized by mixing some other material with it. This may be bitumen or a grout ofconcrete or

21、 some other substance.The base course, which is made of either crushed stone or a layer of thinly-mixedconcrete, comes next, the wearing surface, which may be a layer of asphalt or a seriesof reinforced concrete slabs, is then laid. A concrete surface be laid in segmentsseparated by joints to allow

22、for expansion and contraction under difffering weatherconditions. One method of laying a reinforced concrete wearing surface is to putdown the steel rods, usually in the form of a grill or mesh, after a certain proportion ofthe concrete has been poured. The top level must be poured within twenty min

23、utes of- 5 - the pouring of the bottom level to assure proper bonding. Anther method is to pour theentire thickness of concrete and then force the steel mesh down into it to apredetermined level.A group of machines collectively callled a concrete train usually perform theseoperations at a rate of ab

24、out three-fourths of a meter per minute. A single newmachine called a slipform pawer can perform all the different jobs of a concrete trainexcep laying the reinforcing mesh. However, a technique has been worked out inwhich the mesh is held in place before the machine passes over it and pours concret

25、earoung it . The slipform paver can operate at a rate of about two meters per minute.The construction of airport runways follows similar procedures, except that the slabsin a runway are much wider then those in a highway. Airport runways must also bedesigned to carry the heavy load of the big modern

26、 jumbo jets, as well as to withstanfenormous blastes of heat from the engines of heat form the engines of the aircraft.Theimpact fatcor is also greater with airplanes than with automobiles. Highways differform airport runways, however, insize and strength rather than design andconstruction methods.I

27、f huge concrete freeways are the transportation phenomenon of hort this century, thenthe railroads were the transportation phenomenon of the nineteenth century .Transportation by rail was not unkonw before the invention of steam locomotive in1892, but rail lines had been limited to the short distances over which horses or otherdraft animals pulled the load. Most of the lines were bugreat ilt in conjunction withmining operations. After the steam locomotive became a practical machine, a surg