转体施工的铁路曲线连续槽形梁设计关键技术研究

为了确保转体施工的曲线连续槽形梁结构设计安全可靠,需要解决以下关键技术问题:结构横向受力、日照温差应力较大、支座中心线横向位置、曲线转体结构横向偏载、曲线槽形梁结构受力计算等。通过道砟槽板横向预应力束的合理布置,克服横向连接处主拉应力;通过适当增加边主梁顶板保护层厚度和纵向预应力束的合理布置,控制了日照温差应力;研究合理的横向支撑位置,避免对结构产生横向次应力;曲线悬臂转体结构横向偏载,将球铰中心相对于上下承台设置横向预偏心,解决转动时横向自重不平衡引起梁体侧倾的问题;通过建立平面模型、单梁模型、梁格模型和实体模型,对比分析计算曲线空间结构的受力问题。结果表明:曲线连续槽形梁结构受力均满足规范要求。

Research on Key Technologies of Railway Curved Continuous U-Shaped Beam Design for Rotation Construction

In order to ensure structural safety and reliability in the rotation construction of curved continuous U-shaped beam,the following key technical issues need to be solved: the lateral force of structure,the bid sunshine temperature difference stress,the lateral position of the support center line,the lateral eccentric load of the curved rotation structure,and the structural stress calculation of curved continuous U-shaped beam. Transverse pre-stressing tendons in the ballast channel plate are properly arranged to overcome the principal tensile stress at the transverse joint; the thickness of the protective layer of the side main beam roof is increased and longitudinal pre-stressing tendons are properly arranged to control sunshine temperature difference stress. Transverse secondary stress is avoided by properly arranged lateral support position. The spherical joint center is set up with lateral eccentricity relative to the upper and lower cushion caps and the problem of beam inclination caused by unbalance of lateral dead weight during rotation is thus solved. Plane model,single beam model,grillage model and solid model are established to conduct comparative stress analysis of curved space structures. The results show that the tress of curved continuous U-shaped beam meets the code.