针对大跨度多跨高墩连续刚构桥合拢顺序(合拢方案)对结构内力和累计位移影响规律研究的不足,以8跨一联、主跨120 m、墩高110.3 m的湖南省汝城至郴州高速公路的文明特大桥为例,采用对比的方法分析了大跨度多跨高墩连续刚构桥合拢顺序对结构受力以及位移的影响,以及采用一次张拉或两次张拉两种张拉方式张拉合拢段预应力钢束对合拢段及整个结构的影响。结果表明:不同的合拢顺序对成桥状态结构受力影响不大,但对累计位移有较大影响,而这直接影响挂篮悬臂施工的立模标高;合拢段预应力钢束的张拉方式不同会影响合拢段主梁的下缘应力,而对其上缘和其他节段主梁应力以及位移影响甚微。
Because the research on the influence of different closure schemes on internal force and accumulated displacement of long-and multi-span continuous rigid frame bridges with high piers was insufficient,Wenming bridge located at the Rucheng-to-Chenzhou highway in Hunan Province was investigated to determine the influence of different closure sequences on the bridge and stre-tching modes of the prestressed bundled reinforcement.The bridge is made of 8 spans and its main span is 120 m long.The highest pier of the bridge is 110.3 m high.The results show that the diffe-rent closure sequences have little effect on structural forces,but have an obvious effect on accumulated displacement,which influences the initialize heights of girders in the process of cantilever segment construction.The different stretching modes of the prestressed reinforcement would bring a distinct effect on the stress on the lower edge of the main beam in the key sections,while little effect on the stress on the upper edge of the main beam in the key sections and other sections and the displacement of the entire structure.