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1、西南交通大學(xué)碩士學(xué)位論文大跨度獨(dú)塔斜拉橋抗震措施研究姓名:毛向東申請(qǐng)學(xué)位級(jí)別:碩士專業(yè):橋梁與隧道工程指導(dǎo)教師:鄭史雄20070501西南交通大學(xué)碩士研究生學(xué)位論文第1頁(yè)摘要大跨度斜拉橋通常是交通運(yùn)輸?shù)臉屑~工程,投資大,對(duì)國(guó)民經(jīng)濟(jì)有重大影響:在地震中一旦造成破壞,將造成巨大的經(jīng)濟(jì)損失,并嚴(yán)重影響到災(zāi)區(qū)的抗震救災(zāi)工作和恢復(fù)重建。因此,對(duì)大跨度斜拉橋采取合理有效的抗震措施以確保其在地震中的安全性,具有十分重要的社會(huì)和經(jīng)濟(jì)意義。對(duì)斜拉橋進(jìn)行減震設(shè)計(jì)時(shí),其主導(dǎo)思想是在地震作用下,斜拉橋的內(nèi)力和位移都是越小越好,但通常情況下這兩個(gè)方面往往是相互矛盾的,要使得內(nèi)力反
2、應(yīng)小,往往要付出較大的位移作為代價(jià),反之亦然。本文結(jié)合某獨(dú)塔斜拉橋,通過(guò)大型有限元程序MIDAS/CIVIL分別建立了沒(méi)有減震措施、采用水平拉索減震和采用粘滯阻尼器減震共三個(gè)該橋的計(jì)算模型。通過(guò)模態(tài)分析對(duì)比三個(gè)模型的動(dòng)力特性,然后通過(guò)地震時(shí)程分析,對(duì)比水平減震拉索和粘滯阻尼器的減震效果,并對(duì)阻尼器的阻尼參數(shù)變化對(duì)減震效果的影響進(jìn)行討論。最后發(fā)現(xiàn)合理的選擇粘滯阻尼器可以使結(jié)構(gòu)的位移響應(yīng)和內(nèi)力響應(yīng)同時(shí)減小,提高了斜拉橋的抗震能力和耐久性,符合減震設(shè)計(jì)的思想。本文得到的規(guī)律可以作為該橋抗震設(shè)計(jì)的一個(gè)依據(jù),對(duì)其他類似橋梁的抗震分析和減震設(shè)計(jì)也有一定的參考意義。關(guān)
3、鍵詞:獨(dú)塔斜拉橋粘滯阻尼器時(shí)程分析減震設(shè)計(jì)西南交通大學(xué)碩士研究生學(xué)位論文第lI頁(yè)ABSTRACTItiswellknown,ingeneral,thatthelong-spanbridgeisthehingeoftransportation,whichisheavilyinvestedin,usedfrequentlyandhasimportantinfluenceonnationaleconomy.Oncedestroyed,itwillleadtohugeeconomicloseandheavilyinfluenceearthquakedisaste
4、rreductionandreDairofdisasterarea.Soitisveryimportanttoadopttheeffectiveseismicfortificationmeasurestoinsurethesafetyofthestructureunderearthquake.Whenwetaketheearthquake—reductiondesignofcable·stayedbridgeintoaccount,thesmallinternalfoteeandthedisplacementareanticipatedtogetunde
5、rtheseismicshock,traditionally,ifacable·stayedbridgeWaSdesignedwithoutanyaseismaticmeasures,smallinternalforcealwaysaccordingwithgreatdisplacement.Inthisthesis,threefiniteelementmodelsforasingletowercable—stayedbridgebyMIDAS/CIVILareestablished,whichalewithoutearthquake-reduction
6、measure.withcableretainerandwithviscousdamper.Then,throughmodalanalysisandtime—historyanalysis,theeffeetofcableretaiherandviscousdamperalestudied.Itisshowedthattheviscousdampercouldlowerthedisplacementandintemalforcereactionatthesametime.Soitcallincreasetheaseismaticabilityandthe
7、durabilityofthecable·stayedbridge,andCanaccordwiththeideaoftheaseismaticdesign.TheselawsCallbeusedasthebasisofaseismatiedesignofthebridgeandiSusefulfordirectingaseismaticanalysisandearthquake·reductiondesignofsuchkindbridge.KeyWords:singletowercable—stayedbridge;viscousdamper;tim
8、e.historyanalysis;earthquake—reductionde