岩土工程施工1(国外)课件

J.DavidRogers,Ph.D.,P.E.,P.G.KarlF.HasselmannChairinGeologicalEngineeringMissouriUniversityofScience&TechnologyforthecourseGE441GeotechnicalConstructionPracticeOVERVIEWOFEXCAVATIONANDGRADINGCODESPart1EXCAVATIONANDGRADINGPRACTICESPRIORTODEVELOPMENTOFGRADINGCODESOLDROADCUTSANDFILLSTypicalcutandfilltechniquesemployedinthe19thCentury.Privatepartiesweregiven20-yearleasestoconstructandmanagetollroadsorbridges,solongastheymaintainedthem.FresnoScrappersInventedbyFrankDusyandAbijahMcCallin1885inSelma,California,itwasgiventhename“FresnoScrapper”byJamesPorteousofFresno,whoadoptedthedesignassuperiorthathehadinventedin1882Pulledbyfourmules,FresnoScrapersslowlyovertookthegradingbusiness,spreadingeastwardBy1920theywerethemostwidelyemployedearthmovingdeviceinAmerica,aswellasthecheapest,sellingfor$30to$40apiece,dependingonthemodelSTEAMSHOVELSThesteamshovelwaspatentedin1838,butnotemployedcommerciallyuntil1868,foruseontheUnionPacificRailroad.FromthatdatethemajormanufacturerswereOtis,Osgood,Bucyrus-Erie,Harnischfeger(firstgasolinepowered),Koehring,P&H(firstelectricpowered),andLimaLocomotive.Rail-mountedShovelsRail-mountedBucyrussteamshovelsreignedsupremeinPanamaduringexcavationofthecanalbetween1905-14SlopefailureintoexcavationShovelloadingside-dumpingrailcarsTheBucyrussteamshovelandmostofitscompetitorsweremanufacturedinOhioJohnF.Stevensconceivedtheplantoconstructalockedcanal,usingwaterfromtheChagresRivertocreateavastinlandlake.Thisreducedtherequireddepthofexcavationsby70feet.TheplanwasfavoredbyTeddyRooseveltandapprovedbyCongressonJune29,1906.LookingintothegappingholeofthePanamaCanal’sdeepestexcavations,acrosstheContinentalDivide,asseenonMay17,1913.Note0.5:1sideslopes.TheAmericansendedupexcavating245millionyds3,almostequalportionsbeingdredgedbelowwaterandexcavatedinthedry.GasolineanddieselShovelsSteamshovelshadbeenemployedforrailroadconstructionsince1868.Asautomobilesbeganbeingmassproducedintheearly20thCentury,thedemandforroadsincreaseddramatically.Steamshovelswereonlyusedonthelargestjobs,whererockexcavationmadetheuseofFresnoscrappersimpractical.LeftviewshowsexcavationforSanPabloDamin1920,whileimageatrightshowsexcavationofUSHwy50acrossAltamontPassin1939.BothsitesareintheSanFranciscoEastBay.TrackedShovelsBytheearly1940strackedshovelswerethedominanttoolusedforheavyexcavationforhighwaysandquarries.Allofthesewerecable-controlleduntilthemid-1950s.IncreasingcapacityandmobilityBytheendoftheSecondWorldWartrackedshovelsandmobilerockcrushingplantshadrevolutionizedthespeedwithwhichhighwaysandairportrunwayscouldbeconstructed.BulldozersTheBulldozerwasdevelopedinthelate19thCenturytograderailroadlines.Twobullsorhorses(upperright),orupto4mules(lowerright),couldbeemployedtopullawheeledcaissonattachedtoastiffarmconnectedtoaflatblade,whichextendedoutinfrontoftheanimals,asshownabove.TheadvertisementfromtheWesternWheeledScrapperCo.,aboveleft,isfrom1917.EarlyTrackedDozersBetween1885-1908BenjaminHoltofStockton,Californiagraduallydevelopingagasoline-poweredself-layingtractor,likethatpicturedatupperleft.Itbegansimplyasameansofmotivepower,toreplacehorsesandmules.Holt’s1908tractorclimbingaslopeTheLaPlantChoattractorbulldozerappearedin1923,butitlackedmeaningfulbladeelevationandcontrolBakerManufacturingofSpringfield,Illinois’DozerNo1,whichusedachainhoist,appearedin1927Caterpillarclaimstohavebegunfittingtractorwithdozerbladesasearlyas1921.ThisviewshowsaCAT30withanearlyLeTourneaudozerblade,circa1932.PerfectingthetrackeddozerIn1928LeTourneaubeganproducingdozerbladesforCaterpillartractors,inStockton,CaliforniaAtthattimeLeTourneaualsointroducedcableandwinchcontrolforliftingandtiltingthebigsteelblades,whichalltheircompetitorsadopted,soonthereafter.Thepowertake-offwinch(seenatlowerleft)usingcablecontrolbecamethedominantmeansofcontrollingthedozerbladesuntiltheadoptionofhydraulicactuators,aftertheSecondWorldWar.LeTourneau’scableandwinchcontrolleddozer;whichchangedtheearthmovingbusinessin1928Caterpillar-LeTourneaudozerwithpower-takeoffcablecontrolatadamsiteinMontanain1937.ThetrackeddozerallowsrapidexcavationanddriftingLaTourneaupioneeredthesimplemechanismsthatalloweddozerbladestobelifted,dropped,andangleddownward,likearoadgrader.Withthatkindofcontrol,trackeddozerscouldpush,or“drift”looseearthandrockforaminimalcost,promotinganupsurgeinroadbuildingactivityduringthe1930sand40s.DozersatHooverDamTrackeddozersplayedastaringroleinthehigh-visibilityNewsreelstrumpetingtheconstructionoftheBoulderCanyonProject,between1931-36Dozersareoftenmodifiedtosuitparticulartasks.Upperleft:BucyrusEriedozergradinganAleutianairstripin1943UpperRight:InternationalTD-18dozerretrofittedwithaBucyrus-EriedozerbladeLowerleft:SlopebarbuiltbyPetersonCATfortheFriant-KernCanaljobin1940.Thesebecameincreasinglycommonafterthewar.ModificationsIn1923Letourneauinventedthefirstself-propelledscrapper,shownabove,whichemployedaseriesoffivetelescopingbucketsthatcouldcarry12cubicyardsofsoilThe1923scrapperemployedall-electricdrive,makingitwasthefirstmachinethatcouldexcavateearth,carry