【摘要】 为对城市高架变宽预制节段梁的设计与施工提供依据,考虑设计轻型化、标准化和施工快速化的原则,比选预制节段梁不同变宽方式,分析表明"多个单箱单室+挑臂长度渐变"为6车道及以上中心城区高架桥较适合的变宽方式。以南昌市洪都大道高架桥为背景,针对该变宽方式进行箱梁结构初步设计,并提出变宽预制节段梁横向异步架设施工方法。经有限元验算,采用该变宽预制节段梁结构进行横向异步架设时各箱梁之间受力不均匀,横梁横向弯曲、扭转效应显著。进一步研究箱梁轴向刚度、横梁横向弯曲刚度及箱梁间距等参数对结构受力的影响,提出了箱梁差异化设计和结构分幅2种设计优化方式,最终采用结构横向分幅异步架设的方式解决了初始结构的受力问题。该变宽预制节段梁结构设计与施工方法在洪都大道高架桥中取得了较好的应用效果。更多还原

【Abstract】 Multiple precast girder segment widening methods are compared in accordance with the demands of light components, standardized manufacturing and accelerated construction.It is shown that the appropriate widening method is to add single-cell box girders and expand the cantilever length to allow the viaducts in downtown of a city to accommodate 6 lanes or more.In the case of Hongdu Avenue Viaduct in Nanchang, the box girder structure was preliminarily designed using this widening method, and the method to transversely erect the added girder components in an unsynchronized manner was proposed.As per the finite element verification, the loads were not uniformly carried by the box girders during the transverse and unsynchronized construction of the variable-width precast segment components, the lateral bending and torsional effect of cross beams were significant.The influence of axial and lateral stiffness of the cross beams as well as the spacing of box girders on the load bearing behaviour of the structure was studied.Two optimization methods, including the box girder differential design and layout of split decks, were proposed.The superstructure can be transversely divided into two halves which are not installed in parallel to ensure the rational load bearing capacity of the structure.The amplification effect of the design and construction methods of added precast segmental components to widen the bridge deck on the Hongdu Avenue Viaduct is good.更多还原