土木工程專業(yè)英語LESSON7

§Lesson7Bridge

課程學(xué)習(xí)指南：1.wordslearningPedestrian(行人)ped(pod，詞根)-足pedal(足的，腳的、腳踏

)Subsoil(底土)=sub（前綴：下、次）+soilOverlap(重疊，搭接)=over(前綴：=super)+lap(接)Intersect(交叉)=inter(前綴：相互之間的)+sect(段、部分=part)Bridgeisastructurethatspansobstacles,suchasriversandvalleys,toprovidearoadwayfortraffic.Byfarthemajorityofbridgesaredesignedtocarryautomobileorrailroadtraffic,butsomeareintendedforpedestriansonly.

pedestrian

nounapersonwalkingalongaroadorinabuilt-uparea步行者，行人adjectivelackinginspirationorexcitement;dull缺乏想像力的，平淡無奇的，乏味的為提供交通道路，橋梁是跨越如河流、山谷這樣障礙的一種結(jié)構(gòu)形式，到目前為止，大部分橋梁都是公路橋或鐵路橋，僅有少部分是人行橋。

Anumberofaqueductbridges,mostlyerectedinEuropeinthe19thcentury,carrycanalsandtheirbargetraffic;andatleastonebridge,atNewYorkCity’sKennedyAirport,servestocarrytaxyingaircraftoverahighway.

aqueductbridge

高架水渠verb(taxis,taxied,taxiingortaxying)(intransitive)(ofanaircraft)moveslowlyalongthegroundbeforetakeofforafterlanding:theplanetaxisuptoawaitingcar.takeataxiasameansoftransport:Iwouldtaxihomeandsleeptilleight.大量的高架渠橋于19世紀(jì)在歐洲建成，以保證運(yùn)河和船舶交通的運(yùn)行。最小的一座橋在紐約市的肯尼迪機(jī)場，它主要是把滑行飛機(jī)拖到跑道上服務(wù)的。Thefirstbridgesbuiltbymanprobablyresembledthosestillbeingconstructedbyprimitivepeoplesinisolatedregions.primitive

adj.原始的,早期的簡單的;粗糙的原始人,原始事物人類建成的首批橋類似于原始人在孤立地帶建成的橋。Thetoolsandbuildingskillsofearlyman,likethoseofprimitivepeoplestoday,weresoelementarythathewasundoubtedlyforcedtouseeasilytransportablematerialsthatcouldbeputinplacewithaminimumofformingandshaping.

早期人類的工具和建筑技術(shù)如同原始人類一樣都是最初級的，只有應(yīng)用經(jīng)過簡單加工成型的材料。

Inforestregions,wherestouttimbersorlogscouldbeobtained,bridgesverylikelyweremadeofonemoreparallellogs,possiblycoveredwithcrossbranchesormattingforbetterfooting.stout結(jié)實(shí)的；厚實(shí)的

在森林里，隨處可得結(jié)實(shí)的木材，那時侯的橋極可能是由并排的幾根圓木建成，可能在其上覆一些木枝或草墊以方便行走。

IntropicalregionsofIndia,Africa,andSouthAmerica,fibrousvineswereusedtobuildsuspensionbridges.Thevinesweretiedtotreesorrocksoneachsideofthestreamorvalleytobecrossed.Oneormorevineswereusedtotreadon.Othervines,strungseveralfeethigher,wereusedforhandholds.streamvalley

河谷處于熱帶地區(qū)的印度、非洲、和南美洲，纖維藤用來建成懸索橋，這些藤系在小河或山谷兩邊的樹上或巖石上，一根或更多的藤用于在上面行走，其它的在幾英尺高的地方，用作扶手用。Althoughvineridgesareusuallyunstable,somebuiltbytheIncaswerestrongandstableenoughtobeusedbytheinvadingSpanishsoldiersandhorses.invade侵入;侵略(別國);侵犯(主權(quán)等)擁入;擠滿Thetownwasinvadedbyacrowdoftourists.

雖然藤索橋通常不穩(wěn)定，但印加人建成的藤索橋足夠的堅固和穩(wěn)定性，被用于西班牙士兵和他們馬匹的通行。Inrockyregions,stonewasusedforbridges.Pilesofstonewereplacedatshortintervalsacrosstheriver,providingthebridgepiers,andthenapathfrontbanktobankwasmadebylayingflatstoneslabsacrossadjacentpiers.Afewstonebridgesofthistype,calledclapperbridges,canstillbeseeninDartmoor,England;however,theydateonlyfromtheMiddleAgesorevenlater.

在巖石地區(qū)，石頭被用來建橋，橫跨河流以很小的間距布置石碓作為橋墩，然后用平坦的石頭跨過相鄰的橋墩就建成連接兩岸的通道，大部分的石橋就是這種類型，叫做鼓掌橋?，F(xiàn)在在Dartmoor、英格蘭仍然可見，不過它們都建于中世紀(jì)甚至更晚。ThefirstinnovationbeyondtheprimitivebridgeformsisbelievedtohaveoccurredinancientChinaandthenspreadtoIndia.Tobridgestreamwiderthanasingletreelength,theChineseandIndiansusedtwopilesofthreetrunks,buildingtowardthestreamcenterfromeachbank.pile樁，一堆，一疊

原始橋梁的第一步變革被認(rèn)為出現(xiàn)在中國古代，隨后傳入印度。河床一般比樹要寬，中國人和印度人從河的兩岸到河中央用兩堆樹干來建造。Ineacharmofthestructure,thelogswerepiledontopofoneanotherwithaslightupwardslant,witheachlayerprojectedseveralfeetbeyondtheoneimmediatelybelowit.Forstability,eachpileoftimberswasanchoredbyamassivepileofstoneoneachbank.Nearmidstream,thegapbetweentheendsofthearmswasclosedbytheadditionofasimplebeambetweenthetwoends.每個分支中，圓木一個接一個的布置并微微向上傾斜，使其每一層都比它下面的高幾英尺。為了增加穩(wěn)定性，每個木樁在兩岸都用一堆大而重的石頭錨固；接近河中央，在河中間的兩個分支的兩端則用簡支梁連接。Inthiskindofstructure,acrudecantileverbridge,theachievablespanlengthismadegreaterbytheadditionofacentralsectionbetweenthefreeendsofthearms.

crude天然的,未加工的，簡陋的,粗糙的,未加修飾，粗魯?shù)?粗俗的,粗野的在這種結(jié)構(gòu)中，天然支架橋在兩個分支的兩端加上額外構(gòu)件后可達(dá)到很寬的跨度。Asearlyas4000B.C.inMesopotamiaand3000B.C.inEgypt,overlappinghorizontallayersofstoneorsun-bakedbrickwereusedinsteadofoverlappingtimbers.早在公元前4000年的Ｍesopotamia和在公元前3000年的埃及，用石頭或日光烤干的磚代替木頭被用于橫向覆蓋層。thisconstruction,whichlookslikeamasonryarchthatissteppedratherthansmoothontheundersideiscalledacorbeledarch．這種結(jié)構(gòu)看起來像的磚拱，一層層鋪起，被叫做突拱。T0changethecorbeledarchintoatruearch,itwasonlynecessarytoreorienttheinnerstonessothattheyformedasmoothcurve.要使突拱變?yōu)檎嬲墓?，需要調(diào)整內(nèi)部石頭的構(gòu)造以形成光滑的曲面。Thetruearch，whichwasusedasearlyas3500B.C.,ismuchstrongerthanthecorbeledarch.

這種拱比突拱更堅固，且早在公元前500年就被使用。Thetruemasonryarchwasefficient,economical,anddurable.Itcouldspansmallriversbymultiplearchesrestingonpiers;moreover,itwasgenerallygraciousinappearance.這種石拱經(jīng)濟(jì)和經(jīng)久耐用，它可以由多個跨過橋墩的拱而跨過小的河流，而且外觀非常漂亮。Thesequalitieswerehardtomatchbyanypreviousformofconstruction.ThetruemasonryarchwaswidelyusedinbridgeconstructionbyboththeancientChineseandtheRomans;itremainedinwideuseuntilthe19thcentury.

而它的質(zhì)量比先前的任何結(jié)構(gòu)都要好。在中國和羅馬的古代，這種整體石拱被廣泛地用于橋梁結(jié)構(gòu)。它一直被廣泛地使用直到19世紀(jì)。

Basicallytherearejustfourtypesofstructuresthatcanbeusedtobridgeastreamorotherobstacle:rigidbeams,cantilevers,arches,andsusp