【作者】 张雷；

【导师】 吴海军；

【作者基本信息】 重庆交通大学 ， 桥梁与隧道工程， 2011， 硕士

【摘要】 随着近年来公路铁路基础设施建设的快速发展,我国路网密度明显增加,新建桥梁与现有公路、铁路的立体交叉问题日益常见。为了减少上行桥梁施工对下行交通(特别是铁路运行)的影响,采用平转施工的连续梁桥越来越多。连续梁桥平转施工时,转体段一般采用支架现浇的方法进行制作,其合理分段长度及支架拆除方式对结构的影响、转体过程的安全及稳定监测等问题,目前国内相关研究较少。为此,本文依托山西省交通厅2010年科技计划“大跨度超万吨级连续箱梁桥转体关键技术研究”及长平高速公路微子立交桥平转工程做了如下工作:①针对转体段分段支架施工,分析了不同分段长度对主梁受力性能的影响,计算和比较了混凝土收缩、徐变效应、预应力张拉效应及主梁应力和位移随分段长度变化的规律。②在现浇梁与底模支架之间不同摩阻系数、不同模板约束的条件下,计算了预应力筋张拉时主梁的应力和位移,分析和讨论了梁体有效应力与上述多种因素的关系,提出了降低底模支架摩阻力的措施。③分析了支架现浇施工过程中支架受力的变化过程,讨论了一次拆架和分节段拆架对桥梁施工监控的影响;研究和比较了依托工程不同拆架方式下主梁受力、主梁位移、支架受力,讨论了各种拆架方式的利弊,提出了一种优化的拆架方案,并在依托工程中得到成功应用。④通过对微子立交桥转体过程的监测与分析,提出转体过程的控制要点和注意事项。更多还原

【Abstract】 With the rapid development of road and rail infrastructure in recent years, the density of the road network is significantly increased, which commonly leads to the flyover crossing between the new built bridge and the old roads and railways. The adoption of horizontal swing construction for the continuous beam bridge seems more rational in order to reduce the influence to the down traffic caused by bridge construction, especially the impact on railways. The segments generally are casted on the scaffold before horizontal swing construction, therefore the reasonable segment length and scaffold demolition sequence which are studied less at home and abroad may cause some influence on the structure, the construction safety, the monitoring and so on.Therefore, the relevant research has been carried out on the scientific and technological project of Shanxi communications department (Key technology research on horizontal swing construction of long-span continuous box-girder bridge for super DWT) and a real case of the Weizi overpass project in Shanxi Changping expressway, including following work.①The influence on the internal force caused by variant length of segment is analyzed ,and so do with the effects of shrinkage and creep of concrete , prestressed effect, the relationship between and segment length.②The displacement and stress of the beam has been got with different friction, different constraint caused by the formwork. The influence on the effective stress is discussed with the variable friction coefficients and constraint,and the measures to reduce friction coefficients between the girder and the scaffold are proposed.③The variance process of internal force of the scaffold is discussed in detail when construction, meanwhile the different sequences of the scaffold removal in one time or several times which affect construction monitoring are also covered.Based on the calculation of different sequences,the displacement and stress of the beam, the internal force of the scaffold are got ,and the advantages and disadvantages are compared among the different sequences, finally a optimal removal sequence is proposed and successfully applied in the actual project.④The key points and considerations have been proposed through the Weizi overpass monitoring and analysis.更多还原