大跨徑雙肋式拱橋承載性能研究.pdf

1、重慶交通學院碩士學位論文大跨徑雙肋式拱橋承載性能研究姓名：賈偉紅申請學位級別：碩士專業(yè)：橋梁與隧道工程指導教師：王成吳國松20050322～!!!!墜豎!ABSTRACTInitialgeometricdefectsareinevitableinarchbridges，buttheirinfluencesontheultimatebearingcapacityofthebridgearenotclearInconnectionwithR

2、Cboxribarchbridge(WenxiBridge)，byusingplanestaticanalyticalmethodandspaceanalyticalmethod，stabilityofdifferentconditionsandinfluencesofinitialgeometricdefectsontheultimatebearingcapacityofthebridgewereanalyzedTheresearch

3、workisfocusedonthefollowingaspects：@Comparedwithinfiniterigiditywhentherigidityofabutmentstakestherigidityoftheabutmentwhoseheightis15m，theinfluencesoninnerforceandstabilityofthebridgeweresmall；whentherigidityofabutments

4、takestherigidityoftheabutmentwhoseheightis4morsmallerhorizontalandverticaldisplacementsincreasedespeciallyforthespringsection，verticalrigiditydecreasedalot，momentsincreasedwhileaxialforcesincreased1ittle②Withthehelpof3Df

5、initeelementnumericalsimulation，stabilityofdifferenlconditionswereanalyzedTheresultsindicatedthatthestabilityofthebridgesatisfiedtherequest③Basedonbeamelement，whenthelongitudinallengthoftheinitialgeometricdefectsattheere

6、ctionjointsofthearchribwasbelow20cmandthehei曲texceeded1／3ofthearchbox7Sheight，theinfluencesOUthestructurewerelargeThefirstmodalofstabilityfailureofthepress—bendingarchwasunsymmetrical，thatindicateditwasabifurcatebuckingJ

7、oint—fissurescandecreasestabilitycoefficientalot④Onthcbasisofdifferenthypothesesoftheinitialgeometricdefectswhoseheightfallbelow6cm，byconsideringgeometricnonlinearityandmaterialnonlinearitytheultimatebearingcapacityofthe

8、bridgewereanalyzedwithbeamelementResultsshowedthatthearchwash’tsensitivetothesekindsofdefectsThepress—bendingarchfollowedtheidealdeformationmodal(symmetricaldeformation)untilextremepointcollapseUnderthesamecircumstance，i

9、fthedefectsbecamedeeperandincreasing，theultimatebearingcapacitydecreasedsomewhat，Unsymmetricalgeometricdefectswouldexpeditestructure’SinstabilitySOthesedefectsshouldbeavoidedduringtheconstructionstage⑨Initialgeometricdef