简介:Currently,thedesignpracticeofhighwaybridgesaroundtheworldaremovingtowardslimitstatesdesign,areliability-baseddesignprocedure.CanadianHighwayBridgeDesignCode(CHBDC)isthefirstdesigncodeentirelydevelopedbasedonlimitstatesdesignphilosophy,includingfoundationsandFRPcomponents.However,reliabilityofastructuredecreasesinserviceduetoenvironmentalattacksandmaterialdeteriorationsuchasfatigue,corrosionandmanyotherreasons.Therefore,thestructureshouldbeinspectedperiodically,andthereliabilityofthestructureshouldbeevaluatedaccordingtoitsageandfielddata.Ifitsreliabilityisreducedtoacertainlevel,arepairshouldbescheduledaswellassomepreventivemaintenancemeasuresshouldbeimplementedtopreventfurtherdeterioration.Recently,manyresearchworkshavebeenconductedtoinvestigatereliability-deteriorationmechanismsforeachtypeofinfrastructureanditscomponents,optimizetheinspectionandmaintenancestrategy,predictremainingservicelife,estimateitslifecyclecost.Thispaperisfocusedonthestudyofreliability-deteriorationmechanismsofslabonsteelgirderbridgesduetofatigueandcorrosionofsteelgirdersaswellascorrosionofreinforcementinthedeckslab.Exampleswillalsobegiventoillustratetheproposedlifecyclemanagementstrategyforcompositeslabonsteelgirderbridges.
简介:[摘要]超高层建筑中核心筒承担着实现建筑功能和抵抗荷载的重要角色,通常布置在建筑平面的中心。介绍一种新型的核心筒结构体系———组合式核心筒,核心筒以多个角筒形式分散布置在建筑平面内,各角筒通过拉结大梁连成一体。对拉结大梁的数值模拟方法进行探讨,并对组合式核心筒的刚度进行比分析,同时还对关键构件的受力进行详细分析。研究结果表明组合式核心筒的拉结大梁应采用墙单元来模拟;与中心式布置的核心筒相比,组合式核心筒的抗侧刚度和抗扭刚度明显削弱;组合式核心筒中拉结大梁对整体度影响很大;设计中应对核心筒角部墙体、拉结大梁端部的楼板等重要部位进行加强。