装配式桥梁顶升调坡关键技术研究

Key Technologies of Prefabricated Bridge Jacking and Slope Regulation

以广深高速公路改扩建项目中需纵面抬升的多跨32.5m简支桥面连续T梁桥为背景,为解决此类装配式桥梁顶升设计、顶升高度界限值等关键技术问题,提出了此类桥梁竖曲线拟合分析方法、不同墩柱高度采用不同的断柱接头设计方案,确保顶升过程中桥梁结构安全,提高施工精度;根据小偏心受压理论,以新、老支座垫石交界面处不出现拉应力为控制标准,确定垫石的加高限值并结合桥墩加高盖梁限值分析,得出3种抬升高度界限值使用不同方案的结论;同时,结合桥梁拆除、建筑物移位等新技术,研究了桥梁顶升与抬升设计方案,分析2种施工工艺优缺点,得出其不同适用性,拓展了桥梁调坡改造技术思路。

Taking the multi⁃span 32.5m simple support deck continuous T girder bridge that needs to be lifted longitudinally in Guangzhou⁃Shenzhen Expressway reconstruction and expansion project as the background,in order to solve the key technical problems such as the jacking design of such prefabricated bridges and the limit value of the jacking height,the vertical curve fitting analysis method of such bridges and the design scheme of broken column joints are adopted for different pier column heights to ensure the safety of the bridge structure and improve the construction accuracy during the lifting process.According to the theory of small eccentric compression,taking the absence of tensile stress at the interface of the new and old support cushion stones as the control standard,the height limit value of the cushion is determined and combined with the analysis of the limit value of the pier raised cover beam,the conclusion that three lifting height limit values use different schemes is drawn.At the same time,combined with new technologies such as bridge demolition and building displacement,the design scheme of bridge jacking and lifting is studied,the advantages and disadvantages of the two construction processes are analyzed,and their different applicability is obtained,which expands the idea of bridge slope adjustment and transformation technology.