水利水电专业英语论文英文对照及翻译.docx

水利水电专业英语论文英文对照及翻译.docx

《水利水电专业英语论文英文对照及翻译.docx》由会员分享，可在线阅读，更多相关《水利水电专业英语论文英文对照及翻译.docx（19页珍藏版）》请在冰豆网上搜索。

水利水电专业英语论文英文对照及翻译

Earthandrockdam

Summary

Earthandrockdam,withanothernameas"localmaterialdam",ismainlybuiltwithearthandrockmaterialsnearthesite.Itcanbeclassifiedbasedonthematerialsitused,earthdammainlywithearth,sand,grit,andgravel,androckdammainlywithrockballast,gravel,andexplodedrocks.

Featuresofearthandrockdam

Strongpoints

Withconvenientsupplyofmaterials,manybuildingmaterialssuchassteel,cement,andtimberscanbesaved.Withgranularstructuremoresuitabletofoundationdeformation,itdemandslessonthefoundation.Veryflexiblefromsimpleartificialfillingtohighlymechanizedconstruction,theprocedurebecomesimple,theconstructionbecomeefficient,andthequalityguaranteebecomeeasy.Simplystructured,the costislow,theoperationisconvenient,works isreliable,andmaintenanceandheightaddingisconvient.

Weakpoints

Overflownotallowed,spillwayhastobebuilt.Diversion lessconvenient,costincreases.Sectionlarger,earthtobefillediseasytobeaffectedbyclimate.Thiskindofdifficultmeanspossibleextentionoftimelimitandcostincrease

Earthandrockdamtypes

Basedonconstructingways,earthandrockdamscanbeclassifiedintorolledonesofearth&rock,thrownrock-filledones, rock-filledoneswith directionaldetonation,oneswithearththrownintothewater,andonesfilledbyhydraulicforces. Amongthem,rolledonesaremostpopular.

Basedontheearthproportionandthelocationofanti-seepage parts,therearehomogeneous（even-granular）dams, zonedearthdams,anddamswithartificialanti-seepagematerials.Strongpointsofhomogeneousdams:

onefoldmaterials,simpleprocessweakpoints:

flatgradient,largesection,weather-limited,strongwaterpressureinholes.Zoneddamsareclassifiedintooneswithcoreanti-seepageandoneswithfrontanti-seepage.Lessamountofearth,lessaffectofseason.interferingwiththefillingofthedambody.Lessinterferencewiththeconstructionofthedambody.weakeranti-earthquakeandunevensinking.Theanti-seepagepartsofdamswithartificialanti-seepagematerialsuseasphaltconcrete,reinforcedconcreteorotherartificalmaterials.Sometimes,theanti-seepagepartsareinthedamfrontfacingtheupstream,sometimes,theyareatthecoreofthedam.

Workingconditions

Trapeziformsection

Earth-rockdamisawaterretainingstructurebuiltwithloosegranulesofearthandrocks filledandrollercompacted.Withweakerstrengthbetweenthesegranules,bothupsteamanddownsteamslopeshavetobekeptata certaindegreetoavoidlandslide.Sothedamsectionisusually trapeziform. Itcanbedestablizedintwoways,simpleslopeslidingandsametimeslidingofslopeandfoundationcausedbysheardamage. It'sadifferencefromotherstructures

Seepageeffects

Withalargesection,thedamisgenerallykeptfromentireslidingunlesscausedbyweakinterlayers.Effectedbywaterlevelsattheupsteamanddownsteam,seepageiseasytohappenwithstreamspassingthe fayingsurfacesbetweenthedamandfoundation,andbetweendamearthandconcretebuildings.Theseepingstreams formafreewatersurfaceinsidethedam.Underthesurface,alltheearthbodyissaturated. Dippedinthewater,theearthbecomelighterineffect.Anditsangleofinternalfrictionisnarrowed,and cohesiveforceweakened.Withthehydrodynamicpressurefromtheseepingsteams,moreslidingofdamslopesispossible.Whenseepingsteams movein soil, thedambodyandfoundationwillbedeformedfromtoosteephydraulicgradient.  Sometimesthedamevencrashes.

Scoureffect

Itsanti-scourabilityisweakbecausethecohesiveforcebetweenearthgranulesissmall.Ontheonehand,therainwaterentersthedamandlowerthestabilityofthedam,andontheotherhand,therainscourthedamsurfacealongtheslope.Atthesametime,thewavesinsidethereservoiralsowashoutthedamsurface,puttingthesurfaceintheriskofbeingdamaged.Sometime, landslideevenhappensduetothis. Soeffectiveprotectingmeasureshavetobetakenfordamslopesbothupstreamanddownstream.

Sinkingeffect

Thedambodyandfoundationwillsinkundertheirselfweightandwaterloadbesidesthespacebetweenearthgranules.Ifitsinkstoomuch,theelevationlevelwillnotbesufficient,andthentheoperationofthedamwillbeaffected.And,toomuchunevensinkagewillcausefractureofthedamboday,andevenaseepagepassage,puttingthedamatrisk.

Othereffects

Infreezingregions,anice-coveredlayerwillbeformedoverthereservoirwhenthetemperatureisbelow0degree.Thenthebankslopeanddamslopewillbefrozentogetherwiththeice.Whentheiceexpands,slopeswillbepressed.Inthisway,theprotectingslopeswillbedamaged.Besides,theclayabovethewaterlevelwillhaveholesandcrackseffectedbyfreezingandthawing.Insummer,withwaterlost,theclaywillcracked,makingseepagemucheasier.Earthquakeshavetobetakenintoaccount.Theycanmakelandslidemorepossible.Ifthefoundationismadeofsiltysand,liquidifieddamageismorepossible.

Materialsforbuildingearthandrockdam

Obtainingrawmateriallocallyisabasicdesignprinciple.Generallyspeaking,familiarearthandrockmaterialscanbeused.exceptionsincludeswampysoil,bentonite,surfacesoil,andothersoilmaterialscontainingorganicmatternotcompletelydecomposed.therefore,damtypeisoftendeterminedbasedonavailabilityofearthandrockmaterialsnearbythesite.stockyardmustberichinstorageandnearindistance.Asfortheselection,technicalandeconomicfactorswillbeconsidered.Thedambody ismainlymadeupofdamshell,antiseepage,drainage,andprotectionslope.Theyworkunderdifferentconditions,sotheydemanddifferently.Materialsmustbedurableandsuitabletotheirpurpose.

Antiseepageandstructureofdamcrest

Seepage-proofingworkforadammustbebasedonstructuralandconstructingrequirements,reducingseepagegradient,down-streamsaturationline,andseepagetoanallowanceextent.Wecanuseterreneseepage-prooftingmaterialsand artificialmaterialsincludingasphaltconcreteandreinforcedconcrete.terrenematerialsaremoreused.Roadisbuiltoncrest.Iftrafficisnecessary,roadhastobebuiltbasedonrelevantstandard.Iftrafficisnotanticipated,single-layermasonryorgravelsissufficientforresistingrainscouring.anti-wavewallisbuiltupstream,andrailingsarebuiltdownstream.thewall,usually1to1.3metershigh,isbuiltwithstonemasonryorreinforcingconcrete. itsfoundationmustbefirmlyburiedinthedam,protrudingintoanti-seepage.Forthesakeofrain,theroadonthecrestisusuallybuiltwithslopesononesideoronbothsides.Whenthereisaanti-wavewall,theslopeistowardsdownstream,andtherewillbealengthwaysdrainagedownstreamthedamcrestforgatheringwater.Thewaterwillgodownstreamthroughdrainage.

Damslope

Influencingdamstabilityandconstructiondirectly,damslopeisdeterminedbydamtype,damheight,damscale,materialofdambodyandfoundation,loadto bear,andconditionsforconstructionandoperation.Generallyspeaking,damslopeisinitiallydesignedaccordingtoprojectscompleted.Thenapropersectionisdecidedaftercalculationintermsofstability.Toslopesmadeofsandandsoilinarolleddam,theirgradientisbetween1:

2and1:

4.For damfoundationwhichisweaker,thegradientshouldbeslow.

Forslopedesign,wehavetoconsidertheshearingstrengthwhichofearthwillbereducedduetobeingsoakedinup-streamwater.Soiftheupstreamanddownstreamslopesaremadeofsameearthmaterials,theformeronehastobeslow.forearthdamswithinclinedsoilwalls,theirupstreamslopesareslowerthanthoseofcoredams,andtheirdownstreamslopesaresteeperthanthoseofcoredams.forhomogeneousdamsofsandyloamandloam,theirslopesareslowerthanthoseofdamsmadeofsandandgravels.slopesofhomogeneousdamsmadeofcohesivesoilhavesomethingtodowithdamheight.Thehigherthedamis,theslowertheslopeis.however,gradientsofdamslopesmadeofsandorgravelhavelittletodowithdamheight.Generally,thereisaroadondownstreamslopeevery10to30meters.Whengradientschanges,theroadwillbeatthechangingline.theroadwidthisdeterminedbyitspurposes,butneverlessthan1.5to2.0meters.drainageditchesarebuiltonroadforcollectingrainwater,resistingwash,observing,repairing,andtraffic.

Slopeprotection

Forearthandrockdams,theremustbeprotectionupstreamanddownstream.Forupstream,damagescausedbywavescouring,damwise streamscouring, ice,andfloatermustbeavoided.Fordownstreamofhomogeneousdams,damagescausedbyrainscouring,storm,ice,stream,animal,swelling,andmudcrackmustbeavoided. Iftherearerocks,cobbles,andgravelsdownstream,nomoreprotectionisneeded.Revetmentsmustbesturdyanddurable,abletoresistdamagescausedbyvariousfactors.Theirundercoursemustnotbescoured.Materialsshouldbeusedaslocalaspossibletolowerthecost.Simpleconstructionandconvenientrepairingshouldbeguaranteed.Rocks,stonework,concrete,reinforcedconcrete,andasphaltconcreteareusedforbuildingrevetmentsupstream,andstonework,rocks,gravels,andturfsareusedforthosedownstream.Revetmentsprotectthespacefromdamcresttothelineacertaindistance,normally 2.5m,undertheminimumwaterlevelofthedamupstream.Forthosedownstream,theyprotectthespacefromdamcresttodrainingprismortodamheelineventofnoprism.

概述

土石坝又称“当地材料坝”，主要由坝址附近的土石料填筑而成，根据坝体所用材料不同又可分为土坝和堆石坝。

坝体材料以当地土料和砂、砂砾、卵砾为主的称土坝，以石渣、卵石、爆破石料为主的称堆石坝。

土石坝的特点

优点

筑坝材料就地取材。