預(yù)應(yīng)力混凝土路面的發(fā)展與

TheDevelopmentandResearchofThePrepareShouldDintConcreteRoadSummary：Thistexttotheinternationalcommunityintheaspectsofpreparingshoulddintroadaworkfordoingproceededthereviewandoutlook.Mainbelowafewaspectsproceedstoexpatiate:Prepareattherequestofthedevelopmentofthedintconcreteroad,itsmeritandshortcoming,prepareshoulddintconcreteroadtype,material,thedesignmethod,roadbedcontrols,expensesanditsfutureandfurtherresearchwork.Keywords：Prepareshoulddintconcreteroad；designmethod；development；research1.BriefIntroductionThoughprepareshouldtheprincipleofthedintdrivebroadlyappliedinhouse,bridge...etc.constructionrealm,butintheapplicationontheroadverylimited.Knowtoall,themaincharacteristicoftheconcreteisananti-topressthestrengthfarlargerthananti-pullsthestrength.Prepareshouldthedintconcreteroadistomakesuseofthischaracteristicwell,inadvancetheinflictionpressinworkingtocutshoulddint,theanti-thattoincreaseitbendtopullthestrength,increasingtheacceptancecarrytheability.Prepareshouldthedintconcreteroadincreasestocutthecurvedstrengthinactualanti-of.Generalthicknessis10～15cm.Ifagainthinwillmakethefront-panelproducethebiganenduringfor,toroadfront-panelisalldisadvantageouswiththestabilityofthefoundation,moreover,alsoenlargedtheconstructiondifficulty.Prepareshouldthedintmakeconcreteroadfront-panellongandcanenlargeconsumedly,takinggenerally90～120m,theabroadalsoreaches150～300mlong.2.DevelopmentprocessPrepareshouldthedintconcreteroadisakindofspecialcementconcreteroadthat20centuries40'sempressperioddevelop.UsedinFranceattheearlieststage,usedfortheroadroadorairportatopwithotherEuropeannationsuccessivelyinEnglandafterwards.TheUnitedStates,JapanwaitthenationtoalsoallfixedtosetupwiththeformerSovietUnioncertainthequantitypreparesshoulddintconcreteroadwithairport.AccordingtocarryintheworldanabridgeforpreparingshoulddintconcreteroadappearingintheFrenchLuzancyleadsthewaythetop.ButtherunwayofOrlythatriseintheworldsetsupdidnotmakeprepareuntil1947shoulddintconcreteroadcompleteestablishment.Atthattime,thatrunwayforthesakeofsatisfymodernflyingofdemandbutestablishof.Thealllongatrianglefor,fromtakinghorizontalsteelwirewithsetfront-panelconstitutes.In1953,insamelocation,adoptedtheopeningstypejackonthecontinuousrectangleplankwiththehorizontalsteelwire,otherengineeringsuchas:UsedtheinclineddirectionsteelwireatLuzancyandEsbly,butadoptedtheopeningstypejackonlongtheBourg-Servasroadsegmentofthe295.2mswiththeof"consecutiontype"plank.(namelyhavenotheinflationsew,continuousconcreteplank)Amongthem,anexperimentstheroadisaplanksidethininplankinside,otherisallaverageroughlyathicketc.cuts.FranceisinadditiontousingintheontheroadofBourg-Servasthebeginningofthe5.18MPastarttoprepareshoulddint,preparinglengthwaystotheplankaninflictionshouldthedintisallwithothernationonthequantityclasssamealike.TheFranceengineerdonotapprovethehorizontalinflictionpreparesshoulddint.EnglandjuststartspreparingfromtheroadofCrawleyofthe1950shouldthedintconcreteroadisinvestigative.Thatroadpreparesforthesakeoftheinquisitionprimarilyshoulddintconcreteisintheroadusageindevelopmentscircumstance,designingthefactortothesomewithstartconstructioninthatontheroadthemethod(adoptedtheFreysinnettypesteelwiretohavewithanchorman,asteelwireforgrowingbecamearhombuspatterninacenter)proceededtheresearch.Fixapronofairfield,theroadofEssex,theroadofPortTaLbot,Catwickapronofairfieldetc.thatsetuptheairportofLondonafterwardandagainandsuccessively.PrepareBritishlyshoulddintconcreteroadfront-panelgreatmajorityareallinflationthat"alonetype"of,thenhavethesteelwirewithboxofftosew.Becausetheythink,the"alonetype"plankisgoodfriendswithin"consecutiontype".InEngland,useanetc.slabbroadly,thetriangleplankthatdividedbytouseontheairportofLondonisanoutside.Biggestathatitonceuseisplankthatanetc.slab,butapieceofadoptionopeningstypejackisthickfor10cms.ItisBritishtopreparinglengthwaysshouldthedintisgeneralfor:1.575MPas(highway),3.15MPas(airport),1.925MPas;(inclinedtietosteelwire)Itishorizontaltopreparingshouldthedintisgenerallessthan0.35MPas,inadditiontotriangleplank.AtalittlebitGermanrelevantprepareshouldearlierperiodinknotholeindintanalysistheworkwantstocomparetheothernationearly,butitstheoriesapplicationislimitedbybridgefront-panel,floorplanketc.,notroadfront-panel.JuststarttoconstructtoprepareintheMergelstettenin1953shoulddintroad,constructedafewroadsafterwardandagain.ThePatuxentRiverNavaeAirStationofthepreparedattheearlieststageshoulddintisbuildfromBureauofYardsandDocksin1953ssetupin1954inTheUnitedStates,thisisbeginningthatalongaroadfor,thick17.5cms,lengthwaysthesteelstartedtoprepareshoulddintabout4.9MPas.Fixedthemanyexperimentingtheroadafterwardandagain,theamongthemnearerisfamousNewYorkinternationalairporttoascendin1980setsupofprepareshoulddintconcretecover,thisistheUnitedStatestowillpreparefortheveryfirsttimeshouldthedintconcreteusedforthecompanyusestheairport.AlsoallfixinginHolland,Switzerlandmanypreparingshoulddinta,amongthemnearersetupintheSchipolsuchasHolland.(1980～1987)3.PrepareshouldthemeritandshortcomingofthedintconcreteroadManyresearchesworkexpressestoprepareshouldthedintconcreteroadhavebelowtheadvantageofseveralaspects:(1)theroadfront-panelthicknessneedsthick40%～60%inroadfront-panelintraditionalconcrete.Theveryhighloadinginofferingdinttransformstheabilitywiththehigheranti-,isverybeneficialtothethicknessthatletuptheairport.(2)prepareshouldthedintconcreteroadislongerbecauseoftheplank.Thejointquantitycanreduceconsumedly,improvingthesteadyofacar.(3)prepareshouldtheesseofthedintmakeroadfront-panelstronger,canimprovementinweakpartinCapeinside.Reducedthehorizontalopenningthepossibilityofthe,increasestheenduringoftheroad.(4)prepareshouldthedintconcreteroadusetheamountoflittle.Theresearchpointsout,usedingfornormalpreparingshouldthereinforcingbarthatdintneedwhendesigningmeasuresroughly2.7125kms/m2,thisfarlessthancontinuegotogetherwiththeroad.Itsmainweaknessconsistsin:(1)seefromeconomicstandpoint,lettingupthethicknessoftheroadfront-panel.Butneedtobepreparedafloodoflyshouldmainreinforcingbarindint,constructioncraftthancomplicacy,theworkthathandicraftoperationhasgreatcapacity,andingishardtorealizemechanization,automationconstruction.Theearlyinvestmentisbigger.(2)althoughprepareshouldthedintconcreteroadfront-panelcanmakeoutlonger,withtheincrementofthelength,bepulledbythepiecethatroadbedcausewhencontrolingshouldthedintalsoenlargeimmediately.Moreover,theknotholeadesignformovingdealtoowouldenlarging,thisrightnessofhorizontaljointsesrequestisverystrict.(3)requesttobehightoconstructiontroopspersonnel'scharacter.Needtheproceedingquantitycontrol.4.PrepareshoulddintconcreteroadtypeAccordingtothecurrentdata,startconstructionthemethodcanisdividedintothetwomajortypemostly:Theroadofthe"alonetype"with"consecutiontype"ofroad.The"alonetype"roadistoinstallsthecertainquantityprepareshoulddintreinforcingbar.Beingsewnbylongerstretchandshrinkinpartitiontheroadfront-panelthatbeseparatedconstitutes.Pressinflictiontoprepareshouldthedintcanisdividedintoorderofsequenceandagainfirstpiece'smethodissimilartoempresspiece'smethodistwokindsof,thiswithhouse,thewayofdoingonthebridge,generallymuchafteradoptingpiece'smethod."consecutiontype"theroadistohavenoreinforcingbarroad.(getsingamethodforbecausehavingnotheinflationsews),thiskindofroadcanmakingoutverylongly,accordingtoinflictionpreparingshoulddintcanisdividedintothejackaddsthedintwithfromaddingshoulddint.Thejackaddsthedintisgeneraltosprinkletobuildtheconcreteintwofixedanchormans,combiningtostaythecreviceplacetoaddthedintjack,needingtheconcretehardentoattainafterrulingthestrength,usethejacktoaddthedintfromthebothends,attaintorulethepressure,closethebothendscrevice.Itwillofcoursetheneednotjackininroadindintaddsthedint,butchoosetousetoinflatethecement,theconcretehardens,thephysicalvolumeenlarges,becausethebothendssuffersthestipulationbutmakeautomaticcreationinconcreteinsidepressedshoulddint.Thinkgenerally,the"alonetype"knotholeroadisgoodfriendswithin"consecutiontype"knotholeroad.Mainreasonanistodeducttheroadbedafterrubbingofprepareshouldthedintkeepsalmosttooftenmeasuresinhadinflationsewedroad,butin"consecutiontype"plank,plankcan'tfreeinflation,besidesverylong,frombutmakeitsshouldthedintchangewiththeoutsidertemperature,degreeofhumidityverybig,verydifficultneedtoofprepareshouldthedintproceedtheestimateof.Therefore,adopt"alonetype"roadmoreontheengineering,"consecutiontype"theroadstillisplacedintheresearchandexperimentthestage,theactualapplicationisnotmuch.5.DesignmethodCurrent,internationalcommunitytodesignthatprepareshouldthedintconcreteroadstillhavenoanunitedofmethodsystem,andisallexperienceonacertaindegree,therefore,aninflictionpreparesshoulddintmainfrom:(1)thetransportationcontrols;(2)fromtemperaturewithdegreeofhumidityaflectionforcausingstipulation;(3)theplankcontractstheplankbottomoftheperiodrubsthestipulation.Threefactorsdecides:Squaredistanceinbasicdesignis:Ft+fpf△T+fF+fLTypeinside:Fp——Frompreparingshouldtheconcretethatdintcauseinsideofpressshoulddint;Theft——Concreteallowsflectionshoulddint;(Concretecurvedfoldmoldmeasure/safecoefficient)Thef△T——Isbadtocausefromthetemperatureofshoulddint;ThefF——Isrubbedbyroadbedtocauseofshoulddint;ThefL——Iscausablefromtheflectionthatcontrolshoulddint.TemperatureIfsupposethetemperaturestepsdegreechangealongtheline,so:F△T=(Ecac△T2)/(1-V)TheroadbedrubstocauseofshoulddintFF=μ×ρ×χAmongthem,μisdensitythatroadbedcoefficientoffriction,theρisaconcrete,χfordistancethatbeapartfromthejack.Whenχ=L/2(theLislongforplank),thefFattainsbiggest.Atmakesuretoprepareshoulddintsize,takethefF=μ×ρ×L/2.ThecarriesThecarriesshoulddintcalculationnowallaccordingtotheformulaofWestevgaard,thatmethodassumptionasuggestionforcarryingevenlydistributinginroundprintingtheradiusa,accordingtoTellerwithSutherland,givebelowanusedfortheplanksidewiththecorrectionoutoftheplankCapetype:6.RoadbedstipulationThegrass-rootsavarietyforallexsittingfrictioncontroling,shouldcontrolingarrestmentplankwithtemperature,degreeofhumiditythatisunderanyconcreteplankwithitsbutmove.Inprepareshoulddintconcreteroad,letuptothebestthatfrictioniscountformuch,becauseitisamainfactortocausetoprepareshoulddintlose,italsodecidetheknotholelengthatthesametime.Thoughtheabroadisinthisrespecttohavedonenotafewworks,thesizeofthecoefficientoffrictionisstillhardcertain.Somesectionssuggestioncoefficientoffrictionis0.25～0.5butalsodiscoversitsvalueasinsandoraglideforconstitutinglayersthattryletupthefriction1.25～2.0.Manythecoefficientoffrictionthatindoorsmakesurewhenexperimentingsisallsmallerthanthespot's,thisisbecausetheindoorscouldsnottheconditiontermthatrealityreflectthespotwiththeresultthat.7。ExpensesBuildthepriceexpensesmostcannowthedevelopmentprospectofthenew-bornthing,peopleusuallyevenmakeapointofhowitseconomicperformanceis,butneglectedtheotheraspect.Althoughtheabroaddoesmanyandmoreanalyzingofthetraditionalconcreteroad,can'tstillexplaintheproblem,becausebigparttheworkisallanexperiment,soratiothecostexpensesnaturewantshigherthanexpectsof.Veryobviously,bethetechniqueperfectwithuniversal,itsexpenseswilldescend.Current,fromthesomeinabroadthereportcansee,preparingshouldthedintconcreteroaddifferwithtraditionalroadonthedevelopmentsexpensesnotvery.Althoughthevaluationpreparesshouldthedintconcreteroadprotecttheexpensesoveralongperiodoftimeapparentlyoverearly,itisveryconsiderableineconomicthatprotect.TheBritishCrawleypreparesshouldthedintashowitisbasicwiththedevelopmentsexpensesofthecommonreinforcedconcreteroadsamealike.Atcompleteapieceofknotholebuildbehind,onceproceedtheinvitationtobidfixtosetuptherestplank,theearlierperiodofresultbidsthepricewantstobelowerthananofferforanticipatingusedingforcommonroadbuildingprice,4lowestofferonlycomparingcommonroadhigh6%.Moreover,1980acoveraftertheairportofO'HareoftheUnitedStatesfixsetuptheworldthefirstusedforcompanyusetheairportanof.Table1giveaprojectforfixingbeforesettingupcomparison40yearsin—in—usethetotalcostofthetimelimitanalyzes,thoughtable1havetheestimateofcomposition,thetoocertaindegreeexplainstoprepareshouldtheeconomicperformanceofthedintconcreteroad.Moreover,1980acoveraftertheairportofO'HareoftheUnitedStatesfixsetuptheworldthefirstusedforcompanyusetheairportanof.Table1giveaprojectforfixingbeforesettingupcomparison40yearsin—in—usethetotalcostofthetimelimitanalyzes,thoughtable1havetheestimateofcomposition,thetoocertaindegreeexplainstoprepareshouldtheeconomicperformanceofthedintconcreteroad.Form1ProjecttA

(Commmoncconcrreteroadd)ProjecttBEarlyiitemexpeensess187400001986000039yearrs'jjointtprootectts22850045700Thejoiintssweeppsevvery5yeearswithhtheefilller

((Totaally7tiimes))100140000Needtoocovveraafterr20yearrs5307000Needtoocovveraafterr30yeears864400864400Total44990000287810008．FutureoutlookwithfurtherofresearchInregardtocurrent,stillisinneedoftothecognitionthatprepareshoulddintconcreteroadeveryone's.Theauthorthinksthatdesigntheoriesthatprepareshoulddintconcreteroadwithdevelopmentthatstartconstructionthemethodwillsurroundprimarilybelowafewaspects:(1)needtothelongineverykindofplankofpreparefittinglyshoulddint.(2)knotholeinflation,contractwiththebentcharacteristic.(3)knotholeloadingcharacteristic,amongthemincludetheresearchpreparesshouldthedintloadtheinfluenceoftheabilitytotheknothole,andtotheinfluenceofthetiredcharacteristicetc.inplank.(4)plankandthefrictioncharacteristicofthefoundationandhandlemethod.(5)jointwithdesignthatdrainthesystem.(6)thedevelopmentoftheconstructionprocedure,whethercanusetopaveroadsurfacethewayofdoingtraditionally,oreconomicmethod.Alreadythegreatmajoritythatsetuppreparesshouldthedintconcreteroadallbelongtothe"alonetype"of,butthetype'sroadcan'tmakeoutverylong.(canamounttogenerally120ms)Ifthefrictionproblemoftheroadbedresolved,andto"consecutiontype"oftheroadhadthecertaincognition,fixingtosetupsolong300msorlongerroadsarepossible.Wecanseefromthe"alonetype"with"theconsecutionthetype"thesomecharacteristicoftheroad:Unitesthesetworoadstheusagewouldbemorebeneficial,"consecutiontype"theroadcanusedfortheroadbedconditionthankeeptheontheroadgoodly,the"alonetype"roadusedsfortheroadbedcircumstanceslightlybadwithcurveontheroad.Alongwiththeoriessystemthatprepareshouldthematurityofthedintconcreteroadwithstartconstructiontechnicaldevelopment,prepareshouldthedintconcreteroadwillhavethegooddevelopmentforeground.論文譯文：預(yù)應(yīng)力混凝土路面的發(fā)展與研究摘要：本文對各國在預(yù)應(yīng)力路面方面所做的工作進(jìn)行了回顧與展望。主要就以下幾個方面進(jìn)行論述：預(yù)應(yīng)力混凝土路面的發(fā)展，其優(yōu)缺點、預(yù)應(yīng)力混凝土路面類型、材料要求、設(shè)計方法、路基約束、費用及其未來的進(jìn)一步研究。關(guān)鍵詞：預(yù)應(yīng)力混凝土路面設(shè)計方法發(fā)展研究簡介盡管預(yù)應(yīng)力的原理被廣泛地應(yīng)用于房屋、橋梁等結(jié)構(gòu)領(lǐng)域，但在道路上的應(yīng)用卻很有限。眾所周知，混凝土的主要特性就是抗壓強(qiáng)度遠(yuǎn)大于抗拉強(qiáng)度。預(yù)應(yīng)力混凝土路面就是充分利用這一特性，事先在工作截面上施加壓應(yīng)力。以提高它的抗彎拉強(qiáng)度，提高承受荷載能力。預(yù)應(yīng)力混凝土路面提高了截面的實際抗彎強(qiáng)度。一般厚度為10～15cm。如果再薄會使面板產(chǎn)生過大的撓度，對路面板的耐久性和地基的穩(wěn)定性都不利，另外，也增大了施工難度。預(yù)應(yīng)力使混凝土路面板長可增大很多，一般取90～120m，國外也有長達(dá)150～300m。發(fā)展過程預(yù)應(yīng)力混凝土路面是二十世紀(jì)四十年代后期發(fā)展起來的一種特殊的水泥混凝土路面。最早是在法國使用，后來在英國和其它歐洲國家先后用于道路路面或機(jī)場道面上。美國、日本和前蘇聯(lián)等國家也都修建了一定數(shù)量的預(yù)應(yīng)力混凝土路面和機(jī)場道面。據(jù)載世界上第一條預(yù)應(yīng)力混凝土路面出現(xiàn)在法國的Luzancy的一座橋梁的引路上。但直到1947年，聞名于世的Orly跑道的建成才使預(yù)應(yīng)力混凝土路面完全確立。當(dāng)時，該跑道為了滿足現(xiàn)代飛行的需要而設(shè)置的。全長409.5m，由帶橫向鋼絲和臺座的三角形面板組成。1953年，在同一地點，在連續(xù)的矩形板上采用了開口式千斤頂和橫向鋼絲。其它工程如：在Luzancy和Esbly使用了斜向鋼絲，而在長295.2m的Bourg-Servas路段上采用了開口式千斤頂和墩座的“連續(xù)型”板(無膨脹縫、連續(xù)的混凝土板)。其中，一條試驗路是板邊薄于板中，其他都是平均約15cm厚的等截面。法國除在Bourg-Servas路上使用了5.18MPa的初始預(yù)應(yīng)力外，對板所施加的縱向預(yù)應(yīng)力在數(shù)量級上與其他國家都相同。法國工程師不贊成橫向施加預(yù)應(yīng)力。英國是自1950年的Crawley道路才開始預(yù)應(yīng)力混凝土路面研究的。該路主要是為了調(diào)查預(yù)應(yīng)力混凝土在道路建設(shè)中的使用情況，在該路上對一些設(shè)計因素和施工方法(采用了Freysinnet型鋼絲和錨具，24.6m長的鋼絲在2.25m中心處形成了一個菱形圖案)進(jìn)行了研究。其后又先后修建了倫敦機(jī)場的停機(jī)坪、Essex道路、PortTaLbot道路、Catwick停機(jī)坪等。英國的預(yù)應(yīng)力混凝土路面板絕大多數(shù)都是“單獨型”的，即有鋼絲和分隔的膨脹縫。因為它們認(rèn)為，“單獨型”板要好于“連續(xù)型”。在英國，廣泛地使用15cm等厚板，除在倫敦機(jī)場上用的三角形板為16.25cm外。它曾使用的最大截面是25cm等厚板，而一塊采用開口式千斤頂?shù)陌鍏s為10cm厚。英國的縱向預(yù)應(yīng)力一般為：1.575MPa(公路)，3.15MPa(機(jī)場)，1.925MPa(斜向鋼絲束)；橫向預(yù)應(yīng)力一般少于0.35MPa，除三角形板外。在德國一些有關(guān)預(yù)應(yīng)力板的早期分析工作要比其他國家早，但其理論應(yīng)用只限于橋面板、樓板等，而不是路面板。在1953年才開始在Mergelstetten修筑預(yù)應(yīng)力路面，其后又修筑了幾條道路。美國最早著名的PatuxentRiverNavaeAirStation預(yù)應(yīng)力道面是由BureauofYardsandDocks于1953～1954年建的，這是一條長150m、寬3.6m、厚17.5cm的路面，縱向鋼索的初始預(yù)應(yīng)力大約為4.9MPa。其后又修了許多試驗路，其中較近的就是1980年聞名的紐約國際機(jī)場上所建的預(yù)應(yīng)力混凝土罩面(240m長，45m寬，20～22.5cm厚的跑道)，這是美國首次將預(yù)應(yīng)力混凝土用于商用機(jī)場道面。在荷蘭、瑞士也都修了許多預(yù)應(yīng)力道面，其中較近的如荷蘭在Schipol建的(1980～1987年)。預(yù)應(yīng)力混凝土路面的優(yōu)缺點許多研究工作表明預(yù)應(yīng)力混凝土路面有以下幾方面的優(yōu)點：(1)路面板厚度只需傳統(tǒng)混凝土路面板厚的40%～60%。提供很高的承載力和較高的抗變形能力，對減小機(jī)場道面的厚度非常有利。(2)預(yù)應(yīng)力混凝土路面由于板較長。接縫數(shù)量可大大減少，改善了行車的平穩(wěn)性。(3)預(yù)應(yīng)力的存在使路面板體性較強(qiáng)，邊角軟弱部分得以改善。減少了橫向開裂的可能性，提高了路面的耐久性。(4)預(yù)應(yīng)力混凝土路面的用筋量少。研究指出，用于正常預(yù)應(yīng)力設(shè)計所需的鋼筋量約為2.7125km/m2，這遠(yuǎn)少于連續(xù)配筋路面。其主要缺點在于：(1)從經(jīng)濟(jì)觀點來看，減小了路面板的厚度。但需大量的預(yù)應(yīng)力主筋，施工工藝較復(fù)雜，手工操作的工作量大，難以實現(xiàn)機(jī)械化、自動化施工。初期投資較大。(2)雖然預(yù)應(yīng)力混凝土路面板可以做得較長，但隨長度的增加，由路基約束所引起的張拉應(yīng)力也隨之增大。另外，板的位移量也會增大，這對橫向接縫的設(shè)計要求很嚴(yán)。(3)對施工隊伍人員素質(zhì)要求高。需進(jìn)行質(zhì)量控制。預(yù)應(yīng)力混凝土路面類型據(jù)現(xiàn)有資料，施工方法大致可分為兩大類：“單獨型”的路面和“連續(xù)型”的路面。“單獨型”路面就是配置一定數(shù)量的預(yù)應(yīng)力鋼筋。由間隔較長的伸縮縫相隔的路面板組成。按施加預(yù)應(yīng)力的先后次序又可分為先張法和后張法兩種，這與房屋、橋梁上的做法相同，一般多采用后張法。“連續(xù)型”路面就是無筋路面。（因無膨脹縫而得名），這種路面可以做得很長，按照施加預(yù)應(yīng)力的方法可分為千斤頂加力和自加應(yīng)力。千斤頂加力是一般在兩個固定的錨固端間澆筑混凝土，并留有空隙放置加力千斤頂，待混凝土硬化達(dá)到規(guī)定強(qiáng)度后，用千斤頂從兩端加力，達(dá)到規(guī)定壓力時，將兩端空隙封閉。自應(yīng)力路面不用千斤頂加力，而是選