現(xiàn)代建筑和結(jié)構(gòu)材料

1、2 Modern Buildings and Structural Materials現(xiàn)代建筑和結(jié)構(gòu)材料Many great buildings built in earlier ages are still in existence and in use. (許多早期建造的偉大建筑現(xiàn)在仍然存在和使用著) Among them are the Pantheon(1) and the Colosseum(2) in Rome, Hagia Sophia(3) in Istanbul; the Gothic churches of France and England, and the Renai

2、ssance(4) cathedrals(5), with their great domes(6), like the Duomo(7) in Florence and St. Peters(8) in Rome. (它們是羅馬的潘提翁神廟和大斗獸場，伊斯坦布爾的圣索菲亞教堂；英國和法國的哥特式教堂、文藝復興時期的天主教堂，是大圓屋頂，就象佛洛倫薩的多莫教堂和羅馬的圣伯德大教堂) They are massive structures(9) with thick stone walls that counteract the thrust of their great weight. (他們

3、是用厚石墻建成的大塊結(jié)構(gòu)，厚石墻抵消了他們巨大的重量所產(chǎn)生的推力) Thrust is the pressure exerted by each part of a structure on its other parts. (推力是結(jié)構(gòu)的一部分產(chǎn)生的作用于另一部分的壓力)(1)Pantheon潘提翁神廟（公元前120124年），位于意大利羅馬；(2)Colosseum羅馬大斗獸場（7280年）；(3)Hagia Sophia圣索菲亞教堂（533537年），位于土耳其伊斯坦布爾；(4)Renaissance文藝復興；(5)cathedral天主教堂；(6)Dome圓屋頂，穹頂; (7)Duom

4、o（意大利語）cathedral天主教堂；(8)St. Peters羅馬圣彼得大教堂（15061626年），當時是在拉斐爾和米開朗琪羅等偉大藝術(shù)家們的親自指導下建立起來的，是文藝復興建筑中最完美的代表作。(9)massive(大塊的，塊狀的，巨大的)；massive structure大體積結(jié)構(gòu)/大塊結(jié)構(gòu)These great buildings were not the product of knowledge of mathematics and physics. (這些偉大的建筑不是數(shù)學和物理知識的產(chǎn)物) They were constructed instead on the basi

5、s of experience and observation, often as the result of trial and error(10). (它們不是根據(jù)經(jīng)驗和觀察建造的，常常是反復試驗的結(jié)果) One of the reasons they have survived is because of the great strength that was built into them-strength greater than necessary in most cases. (它們?nèi)匀槐４嫱旰玫脑蛑皇墙ǔ伤鼈兊膹姸冗h大于大多數(shù)情況下所必需的強度) But the engin

6、eers of earlier times also had their failure. (但是早期的工程師也有失敗的情況) In Rome, for example, most of the people lived in insulae(11), great tenement(12) blocks that were often ten stories high. (例如在羅馬，大多數(shù)人居住在群屋或出租的十層高的經(jīng)濟公寓內(nèi)) Many of them were poorly constructed and sometimes collapsed with considerable los

7、s of life(13). (這些房屋建筑結(jié)構(gòu)很差，有時倒塌使其使用期大大縮短)(10)trial and error 反復試驗，試錯法，嘗試法；(11)insula公寓，群屋，建筑群；(12)tenement經(jīng)濟公寓，出租的房子；(13)loss of life使用期縮短，壽命縮短；Today, however, the engineer has the advantage not only empirical information, but also of scientific data that permit him to make careful calculations in a

8、dvance. (現(xiàn)在工程師的優(yōu)勢在于不僅可以利用經(jīng)驗的數(shù)據(jù)，也可以利用科學的數(shù)據(jù)，這些科學的數(shù)據(jù)使得他們可以事先進行詳細的計算) When a modern engineer plans a structure, he takes into account the total weight of all its component materials. (當一個現(xiàn)代的工程師設(shè)計一個結(jié)構(gòu)時，他要考慮所有組成部分材料的總重量) This is known as the dead load(恒載), which is the weight of the structure itself. (稱為靜

9、載，即結(jié)構(gòu)自身的重量) He must also consider the live load（活載）, the weight of all the people, cars, furniture, machines, and so on that the structure will support when it is in use. (他也必須考慮活載，即結(jié)構(gòu)在使用時將要承受的所有的人、汽車、設(shè)備、機械等的重量) In structures such as bridges that will handle fast automobile traffic, he must consider

10、 the impact(沖擊), the force at which the live load will be exerted on the structure. (像橋這樣涉及到快速汽車交通的結(jié)構(gòu)，必須考慮沖擊，也即活載作用在結(jié)構(gòu)上的力)He must also determine the safety factor（安全系數(shù)）, that is, an additional capability to make the structure stronger than the combination of the three other factors. (它必須確定橋的安全系數(shù)，也就是

11、說橋要有一個額外的能力，使結(jié)構(gòu)能承受的力大于其他三個因素結(jié)合的力)The modern engineer must also understand the different stresses to which the materials in a structure are subjects. (現(xiàn)代工程師必須明白材料在結(jié)構(gòu)中所承受的不同應力) These include the opposite forces of compression(壓力、壓縮) and tension(拉力、張力). (這些應力包括壓力和拉力兩個相反方向的力) In compression the material

12、 is pressed or pushed together; in tension the material pulled apart or stretched, like a rubber band. (在壓力作用下，材料被壓或推在一起；在拉力作用下，材料象橡皮筋一樣被拉開或伸長) In addition to tension and compression, another force is at work, namely shear(剪力、剪切), which we defined as the tendency of a material to fracture along the

13、lines of stress. (除了拉力和壓力外，工作中的另一種力叫剪力我們定義為材料沿著應力線斷裂的趨勢) The shear might occur in a vertical plane, but it also might run along the horizontal axis of the beam, the neutral plane(中性面), where there is neither tension nor compression. (剪切可能發(fā)生在豎直面內(nèi)，也可能沿著梁的水平軸發(fā)生，既沒有拉力也沒有壓力的截面叫中性面)Altogether, three force

14、s can act on a structure (三個力可以作用在一個結(jié)構(gòu)上): vertical-those that act up or down; horizontal-those that act sideways; and those that act upon it with a rotating or turning motion. (豎直方向的力向上或向下，水平方向上的力作用于一側(cè)，那些作用于其上的力產(chǎn)生旋轉(zhuǎn)或轉(zhuǎn)動運動) Forces that act at an angle are a combination of horizontal and vertical force

15、s. (以一定角度作用的力是水平力和豎直力的合力) Since the structures designed by civil engineers are intended to be stationary or stable, these forces must be kept in balance. (土木工程師設(shè)計的結(jié)構(gòu)要想保持靜止或穩(wěn)定，這些力必須保持平衡) The vertical forces, for example, must be equal to each other. If a beam supports a load above, the beam itself mu

16、st have sufficient strength to counterbalance that weight. (例如豎直力必須彼此相等，如果一個梁承受其上的荷載，梁本身必須有足夠的強度來平衡它的重量) The horizontal forces must also equal each other so that there is not too much thrust either to the right or to the left. (水平力也必須相等，以至于沒有太多向左或向右的推力) And forces that might pull the structure aroun

17、d must be countered with forces that pull in the opposite direction. (拉結(jié)構(gòu)的力必須抵消相反方向的拉力)One of the most spectacular engineering failures of modern times, the collapse of the Tacoma Narrows Bridge in 1940, was the result of not considering the last of these factors carefully enough. (當代最引人注意的工程失敗的實例是1

18、940年（美國）塔科馬港跨達達尼爾海峽大橋的坍塌，他是沒有仔細充分地考慮這些因素的結(jié)果) When strong gusts of wind, up to sixty-five kilometers an hour, struck the bridge during a storm, they set up waves along the roadway of the bridge and also a lateral motion that cause the roadway to fall. (在一場暴風雨中，當強陣風以65km/h的速度撞擊橋時，暴風掀起的波浪沿橋面運動，引起了橋面的側(cè)向

19、運動，造成了橋面坍塌) Fortunately, engineers learn from mistakes, so it now common practice to test scale models of bridges in wind tunnels(14) for aerodynamic resistance. (幸運的是工程師們從這次失敗中吸取了教訓，現(xiàn)在根據(jù)空氣動力學阻力特性在風洞內(nèi)進行橋梁模型試驗是很普通的事)(14)wind tunnel (test) 風洞(試驗)The principal construction materials of earlier times we

20、re wood and masonry brick(圬工磚), stone, or tile(瓦), and similar materials. (早期的主要建筑材料是木材和圬工磚、石、瓦或類似材料) The courses or layers were bound together with mortar(砂漿) or bitumen(15), a tar-like substance or some other binding agent. (層與層間用砂漿、瀝青、焦油類的物質(zhì)或其他粘結(jié)劑將他們結(jié)合在一起) The Greeks and Romans sometimes used iro

21、n rods or clamps(16) to strengthen their buildings. (希臘和羅馬人有時用鐵棒或夾鉗來加固他們的建筑) The columns of the Parthenon(17) in Athens, for example, have holes drilled in them for iron bars that have now rusted away. (比如在雅典的帕提儂神廟的柱子內(nèi)就有鉆孔，孔內(nèi)有已經(jīng)腐朽的鐵棒) The Romans also used a natural cement(水泥) called pozzolana(火山灰，白榴

22、火山灰), made from volcanic ash(火山灰), that become as hard as stone under water. (羅馬人使用一種來自的天然水泥，叫火山灰，這種水泥在水中會變得像石頭一樣堅硬)(15) bitumen瀝青；asphalt, pitch(16) clamp夾子，夾鉗，卡緊(17)Parthenon帕提儂神廟指古希臘雅典城邦的保護神雅典娜·帕提儂的神廟，是古希臘全盛時期建筑與雕刻的主要代表作。Both steel and cement, the two most important construction materials of

23、 modern times, were introduced in the nineteenth century. (鋼(制品)和水泥當代最著名的兩種建筑材料被采用是在19世紀) Steel, basically an alloy of iron and a small amount of carbon, had been made up to that time by a laborious process that restricted it to such special uses as sword blades. (鋼是鐵和少量碳組成的合金。在那個時期，鋼只能在實驗室中生產(chǎn)，專用于刀刃

24、) After the invention of the Bessemer process(18) in 1956, steel was available in large quantities at low prices. (直到1856年貝色麥法發(fā)明以后，鋼得以低價大量利用) The enormous advantage of steel is its tensile strength(19); that is, it does not lose its strength when it is under a calculated degree of tension, a force w

25、hich, as we have seen, tends to pull apart many materials. (鋼的最大優(yōu)點是它的抗拉強度，也就是說他在計算的拉伸度內(nèi)強度不會損失，這個拉力如我們看到的一樣企圖將許多材料拉開) New alloys have further increased the strength of steel and eliminated some of its problems, such as fatigue(疲勞), which is a tendency for it to weaken as a result of continual changes

26、 in stress. (新的合金增加了鋼的強度，消除了它的一些問題，比如疲勞問題，即在連續(xù)變化應力作用下材料性能惡化的趨勢)(18)Bessemer process貝色麥法，又稱酸性底吹轉(zhuǎn)爐煉鋼法，由英國冶金學家Henry Bessemer 在1856年首創(chuàng)。這是一種不需外熱的、可大量生產(chǎn)的煉鋼方法。(19)tensile strength抗拉強度； compression strength; compressive strength抗壓強度； shear strength; shearing strength抗剪強度；Modern cement, called Portland cemen

27、t(20), was invented in 1824. (現(xiàn)代水泥叫硅酸鹽水泥，發(fā)明于1824年) It was a mixture of limestone(石灰石) and clay(粘土), which is heated and then ground into a powder. (他是石灰石和粘土被加熱后磨成的粉末狀的混合物) It is mixed at or near the construction site with sand, aggregate(21) (small stones, cruhshed rock, or gravel), and water to mak

28、e concrete(22). (在施工現(xiàn)場或其附近,水泥同砂子、骨料（小石子、碎石或礫石）、水混合制成砼) Different proportions of the ingredients(混合物成分，配料) produce concrete with different strength and weight. (混凝土成品混合物成份比例不同，強度和重量也不同) Concrete is very versatile; it can be poured, pumped, or even sprayed into all kinds of shapes. (砼具有良好的可塑性，他能被灌注、泵送

29、甚至噴射成各種形狀) And whereas steel has great tensile strength, concrete has great strength under compression. (這樣一來，鋼有很高的抗拉強度，混凝土有很高的抗壓強度) Thus, the two substances complement each other. (因此這兩種材料彼此互補)(20)Portland cement硅酸鹽水泥；波特蘭水泥；普通水泥 Portland-slag cement；slag Portland cement礦渣硅酸鹽水泥 Portland fly-ash ceme

30、nt粉煤灰硅酸鹽水泥 (21) aggregate骨料；fine aggregate細骨料；coarse aggregate粗骨料 (22) reinforced concrete鋼筋砼； prestressed concrete預應力砼； asphalt concrete瀝青砼； crushed concrete碎石砼； bubble concrete泡沫砼； bulk concrete大體積砼； blown-out concrete充氣砼，多孔砼；high-early strength concrete 早強砼；design of concrete mix 砼配合比設(shè)計age of con

31、crete 砼齡期They also complement each other in another way: they have almost the same rate of contraction and expansion. (他們也用另一種方式互補，他們的伸縮比幾乎相同) They therefore can work together in situations where both compression and tension are factors. (因此當只考慮拉壓時他們能在一起工作) Steel rods are embedded in concrete to mak

32、e reinforced concrete in concrete beams or structures where tension will develop. (在砼梁或結(jié)構(gòu)的受拉區(qū)砼中埋入鋼筋制成鋼筋砼) Concrete and steel also form such a strong bond-the force that unites them-that the steel cannot slip within the concrete. (砼和鋼形成一個強有力的骨架，鋼在砼內(nèi)不能滑動，因為有力將他們結(jié)合在一起) Still another advantage is that s

33、teel does not rust in concrete. (另一個優(yōu)點是砼對鋼不腐蝕) Acid corrodes steel, whereas concrete has an alkaline chemical reaction, the opposite of acid. (因為酸腐蝕鋼，而砼具有酸的相反物堿的化學反應)Prestressed concrete is an improved form of reinforcement. (預應力砼是鋼筋砼的一種改進形式) Steel rods are bent into the shapes to give them the necessary degree of tensile strength. (在抗拉強度范圍內(nèi)施加一個力，使鋼筋彎曲成型) They are then used to prestress concrete, usually by pretensioning or posttensioning method(23). (它們預加應力于砼時，通常采用先張或后張法) Prestressed concrete has made it possible to develop buildings with unusual shapes,(預