資源描述:
《淺論隔震曲線梁橋三維地震反應(yīng)分析》由會員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、華中科技大學(xué)碩士學(xué)位論文隔震曲線梁橋三維地震反應(yīng)分析姓名:林凱申請學(xué)位級別:碩士專業(yè):結(jié)構(gòu)工程指導(dǎo)教師:李黎20070529華中科技大學(xué)碩士學(xué)位論文摘要隨著現(xiàn)代交通體系的快速發(fā)展,曲線梁橋得到越來越多的應(yīng)用。由于曲線梁橋相對與直線梁橋的復(fù)雜性與獨(dú)特性,其抗震設(shè)計(jì)方法還不完善。本文對隔震曲線梁橋三維地震反應(yīng)進(jìn)行了研究,主要包括以下幾個(gè)內(nèi)容:首先,對三維地震動隨機(jī)過程進(jìn)行譜特征正交變換,在空間某點(diǎn)定義了一組地震動譜主分量,三個(gè)地震動譜主分量在任意時(shí)間差時(shí)互不相關(guān),利用譜主分量間互不相關(guān)的性質(zhì),推導(dǎo)出三維地震動
2、隨機(jī)模擬公式;可以假定某一點(diǎn)上在任意時(shí)間差時(shí)互不相關(guān)的譜特征分量在兩點(diǎn)間也互不相關(guān),依此假定建立了兩點(diǎn)間不同分量的相干函數(shù)模型。其次,給出曲線坐標(biāo)系下的隔震曲線梁橋有限元建模方法。首先利用計(jì)入翹曲影響的每結(jié)點(diǎn)八自由度的曲梁單元,推導(dǎo)出橋墩單元的剛度矩陣、質(zhì)量矩陣和三個(gè)方向地震質(zhì)量矩陣。然后使用可以模擬鉛芯疊層橡膠支座的雙向耦合效應(yīng)的微分型恢復(fù)力模型,并用四階龍格-庫塔方法模擬鉛芯橡膠支座單元恢復(fù)力,由此可得到支座單元的切向剛度矩陣。最后,編制MATLAB有限元程序與地震動模擬程序,計(jì)算某不隔震與隔震三跨連
3、續(xù)曲線梁橋在三維地震與單維地震作用下的反應(yīng)。計(jì)算結(jié)果表明:相對在單維地震作用下結(jié)構(gòu)地震反應(yīng),在三維地震作用下結(jié)構(gòu)可能產(chǎn)生更大地震反應(yīng),因此計(jì)算曲線梁橋地震反應(yīng)時(shí)應(yīng)考慮三維地震作用。關(guān)鍵詞:曲線梁橋曲梁單元鉛芯橡膠支座三維地震特征正交分解I華中科技大學(xué)碩士學(xué)位論文AbstractAsthedevelopmentofmodermtrafficsystem,curvedbridgesareadoptedmorewidely.Forthecomplexityandtheparticularity,research
4、ofseismicdesignofcurvedbridgesisstillfaultiness.Thisthesispresentsaseismicresponsestudyofcurvedbridgesunderthree-dimensionalearthquakeexcitations.Andthemajorcontentisasfollows:Firstly,applytheProperOrthogonalDecompositionofthegroundmotionprocessesinthefor
5、mofaspectralpropertransformation(SPT),andtheSPTofthe3-V1-Dgroundmotionprocessesateachpointofthespacedefinesanewsetofgroundmotionprocessescomponents,calledspectralpropercomponentsanduncorrelatedforanytimelag.Assuming,asseemsphysicallyreasonable,thatprincip
6、alcomponentsuncorrelatedatonesinglepointremainuncorrelatedindifferentpoints,makesitpoffibletoobtainanewmodelofthetow-pointcoherencefunctionofthedifferentseismicgroundmotionscomponentssoastocompletethestatisticalmodelofthe3-V,4-Dseismicgroundmotions.Embedd
7、ingthespectralprincipalcomponentsinaMonteCarloframework,makesthismodelveryattractiveforthedigitalsimulationofseismicgroundmotion.Secondly,toincludethewarpingeffectthecurvedbeamelementwitheightdegreesoffreedomisutilized.Theelementstiffnessmatrix,elementmas
8、smatrixandseismicmassmatrixinthreedirectionsforbothgirderandpierelementshavebeenderived.Thebilateralcoupledrestoringforcemodelofleadrubberbearingsisintroduced,andtheelementstiffnessmatrixforthebearingelementcanbeder