九堡大桥连续组合梁桥关键问题研究-桥梁与隧道工程专业论文.docx

摘 摘 要 预应力钢一混凝土连续组合梁桥充分发挥了锶材与混凝土的优点，通常采用 先顶推钢梁后铺设桥面板的方法施工，近年来这种结构体系在我国的应用日益广 泛，但理论研究却滞后于工程实际。因此，本文选择顶推法连续组合梁桥的关键 问题进行研究，为同类桥梁的设计与施工提供参考． 本文以九堡大桥预应力钢一混凝土连续组合梁为工程背景，从钢梁顶推、桥 面板铺设到正常运营进行全过程分析。建立了顶推法槽形钢梁在局部荷载作用下 的简化计算模型，采用有限元方法探讨了顶推设备纵向长度、结构设计参数、初 始几何缺陷对承载力的影响，得到了顶推法槽形钢梁的最优参数。在此基础上， 建立了槽形钢梁顶推分析的有限元模型，研究了支撑反力、截面应力、导梁前端 位移等时程变化规律，探讨了支撑刚度对局部受力的影响，并通过顶推中的实测 数据验证了分析的可靠性． 连续组合梁桥在桥面板铺设过程中，结构刚度和所受荷载不断变化，本文比 较了桥面板采用一次铺设法、连续铺设法和间断铺设法对结构受力的影响，结果 表明间断铺设法最优，有利于降低中支点混凝土的拉应力。 针对预应力连续组合梁桥运营过程中的变形计算，采用能量法推导出理论公 式，考虑了中支点混凝土开裂和预应力增量的影响，给出了跨中挠度的计算图表， 并通过模型试验和桥梁荷载试验验证了理论公式的精确性。 关键词：连续组合梁；槽形钢梁；顶推；极限承载力；受力性能；桥面板铺设； 变形分析 Ⅱ ABSTRACTPro-stressed ABSTRACT Pro-stressed continuous steel-concrete composite beam bridge,which taking the advantages of steel and concrete，is generally constructed by way of first launching steel girder then casting concrete slab．In recent years，this structure has made increasingly progress while theoretical research has lagged behind．Therefore，this paper did a research on key issue in continuous composite beam bridge,which Call also worked as a reference for design and construction in bridges alike． This paper used the pre-stressed continuous steel-concrete composite beam of Jiubao Bridge as a cflse，analysed the whole process of steel U-girder launching, concrete slab easting and bridge operating．A simplified computation model of steel U-girder under local load was suggested．Launching device len#a,structure design parameters，imtial geometry imperfection on meir impacts of limit capacity were discussed，and then the best parameters of steel U—girder were confirmed．Based on them，this paper established a finite dement model of steel U-girder during launching, analyzed support reaction，section stress and nose deflection of time-history as well as the effect of support rigidity．It also verified the reliability of analysis through measurement data during launching． In the concrete slab casting of continuous composite beam，the stiffiaess and load change constantly． Influence of ca