潼河桥（64+108+108+64）连续梁桥抗震设计研究TongBridge(64+108+108+64)onseismicdesignofcontinuousgirderbridge摘要地壳岩石在地球内力的作用下，发生错位或断裂，从而导致的震动，这种效果就叫做地震。地震在发生破坏时，兼具能量大、范围广和难以预测等特点，在地震几十秒的持续作用时间内，能够造成巨大的生命及财产损失，与其他自然灾害相比，其突发性和破坏性的特点尤为突出。汶川地震中部分连续桥梁受损破坏，使桥梁工程的抗震设计获得了重视。提托潼河桥，基于模态分析、瞬态动力法研究了依托工程-潼桥在三种不同的地震波作用下的动力响应。获得结论如下：(1)针对矮墩高度以及是否考虑桩土效应，建立了4种不同工况，对潼河桥三维模型进行了模态分析。结果表明：1）矮墩高度减小后，结构整体刚度增加，桥梁自振频率随之变大，并且桥的振型也随之改变。即：矮墩高度变化后，桥梁的动力特性随之改变；2）是否考虑桩土效应对结构自振频率有影响，若不考虑，结构的各阶自振频率略有升高。(2)基于瞬态动力法研究了依托工程-潼桥在三种不同的地震波作用下的动力响应。结果表明：1）E波与T波作用下主梁的位移及内力较为接近，但明显大于人工波；最大竖向位移出现于主梁跨中截面以及靠近矮墩边跨梁跨中截面处。最小竖向位移出现于边跨根部，只占跨中位移的6%左右；2）同一种地震波作用下，结构各截面纵向位移十分接近，且最大值均出现在高墩边跨梁根部截面处；3）最大剪力值均出现在主梁跨中截面，弯矩最大位置均在墩边跨根部；4）不同地震波作用下，墩顶和墩中的纵向位移、剪力和弯矩均有不同，E波、T波作用下结构响应较大，人工波作用下响应较小。关键词：预应力混凝土梁桥；地震；模态；一致激励AbstractEarthquakesarevibrationscausedbydislocationorruptureoftheearth'scrustundertheinfluenceoftheearth'sinternalforces.Theearthquakedestructiveenergyanddamagecharacteristicsofawiderangeanditisdifficulttopredict,theearthquakeoftenlastsonlytensofseconds,butmaycausehugelossoflifeandproperty,thesuddenanddevastatingnaturaldisasterscannotbecomparedtoother.IntheWenchuanearthquake,somecontinuousbridgesweredamagedanddamaged,whichmadetheseismicdesignofbridgeengineeringpaymoreattentionto.TitoTongBridge,modalanalysis,transientdynamicmethodbasedontheproject-TongBridgeinthreekindsofseismicwavesunderdifferentresponsesbasedonthe.Conclusionsareasfollows:(1)fortheshortpierheightandconsideringtheeffectofpileandsoil,established4differentconditions,thethree-dimensionalmodeloftheTongBridgemodalanalysisiscarriedout.Theresultsshowthat:1)aftertheheightofthepierdecreases,theoverallstiffnessofthestructureincreases,thenaturalfrequencyofthebridgebecomeslarger,andthevibrationmodeofthebridgechangesaccordingly.Thatistosay,whentheheightoftheshortpierischanged,thedynamiccharacteristicsofthebridgewillchange;2)whetherthepile-soileffectshouldbeconsideredinresponsetothenaturalfrequenciesofthestructure;ifnotconsidered,thenaturalfrequenciesofthestructuresareslightlyincreased.(2)transientdynamicmethodbasedonthestudyofthepowerinthethreekindsofseismicwavesunderdifferentresponsebasedontheproject-Tongbridge.Theresultsshowthat:1)thedisplacementandinternalforceofthemainbeamundertheactionofEwaveandTwaveareclose,butobviouslylargerthantheartificialwave;themaximumverticaldisplacementoccursatthemidspansectionofthemaingirderandnearthecrosssectionofthecrosssectionoftheshortpierside.Theminimumverticaldisplacementinsidespanroot,onlyabout6%ofthemidspandisplacement;2)effectsofthesamekindsofseismicwaves,thelongitudinaldisplacementofstructureofeachsectionisveryclose,andthemaximumvalueappearedinthehighpiersidespanbeamrootsection;3)themaximumshearforcevaluesinth...
