新概念2 第64课 课件.ppt

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1、NewConceptEnglish（Book2）(新概念英语)（第二册）新概念二Lesson64TheChannelTunnel海峡隧道TheChannelTunnel----Theworld'slongestunderseatunnelWhatisUnderseatunnel?Anunderseatunnelisatunnelwhichispartlyorwhollyconstructedunderabodyofwater.Advantages:Tunnelingwillgeneratesoilthathasbeenexcavated[ˈekskəˌ

2、veɪtid]andthiscanbeusedtocreatenewland,aswasdonewiththesoiloftheChannelTunnel.Travellingthroughatunnelissignificantlyquickerandwon'tbeinfluenceduringadverseweather>>TheChannelTunnelalsoreferredtoastheChunnelisa50.5-kilometreundersearailtunnellinkingFolkestoneintheUnitedKingdomwi

3、thCalaisinnorthernFrancebeneaththeEnglishChannelattheStraitofDover.ProfileofTheChannelTunnel:>>Atitslowestpoint,itis75metersdeep.At37.9kilometers,theChannelTunnelpossessesthelongestunderseaportionofanytunnelintheworld,althoughtheSeikanTunnelinJapanisbothlongeroverallat53.85kilom

4、eters,anddeeperat240metersbelowsealevel.TheSeikanTunnelTheChannelTunnelIdeasforacross-Channelfixedlinkappearedasearlyas1802beganconstructionin1988andopenedin1994eventuallyclosedin2002forincidentTheBritishChannelTunnelGroupconsistedoftwobanksandfiveconstructioncompanies,whilethei

5、rFrenchcounterparts.TheFrenchChannelTunnelGroupconsistedofthreebanksandfiveconstructioncompanies.Thedesignandconstructionwasdonebythetenconstructioncompanies.Engineering：Geologicalprofilealongthetunnelasconstructed:>>ThegeologygenerallyconsistsofnortheasterlydippingCretaceousstr

6、ata.>>Forthemajorityofitslengththetunnelboresthroughachalkmarlstratum.>>Successfultunnellingunderthechannelrequiredtheselectionofthebestrockstrata.Typicaltunnelcrosssection:withaservicetunnelbetweentwinrailtunnels.Shownlinkingtherailtunnelsisapistonreliefduct,necessarytoma

7、nagepressurechangesduetothemovementoftrainsConstruction：PrecastsegmentalliningsinthemainTBMdriveswereused,butdifferentsolutionswereusedontheEnglishandFrenchsides.>>OntheFrenchside,neopreneandgroutsealedboltedliningsmadeofcastironorhigh-strengthreinforcedconcretewereused.>>Onth

8、eEnglishside,themainrequirementwasforspeedandbo