【摘要】 【目标】以某大跨混合连续梁桥为依托背景，研究混合连续梁桥钢-混结合段传力机理及构造参数，为提升桥梁结构安全性和实现精细化设计提供理论依据。【方法】利用有限元软件Abaqus,建立实桥钢-混结合段精细化有限元模型进行静力分析，探索荷载沿顺桥向传递的基本特征和规律；通过应力积分的方式，得出混凝土以及各钢构件的轴力分担比例，以揭示此类混合连续梁桥钢-混结合段传力机理，并探讨不同构造参数对结合段传力性能的影响；根据计算结果对比分析，给出各参数具体取值建议。【结果】钢-混结合段在承压板处以及结合段与混凝土梁过渡段相接处出现应力突变，产生原因在于荷载传递先由钢构件单独受力，再变为结合段钢格室与结合段混凝土协同受力，最后转变为混凝土梁过渡段单独受力；钢梁过渡段能有效将荷载均匀扩散至承压板上，承压板与其他钢构件相接处易出现应力集中，且承压板作为主要传力构件分担轴力占比为57.38%。【结论】综合考虑将此类大跨混合连续梁桥钢-混结合段承压板厚度控制在50～70 mm,钢格室顶、底板板厚控制在20～28 mm,混凝土强度等级为C50～C60较为合理。更多还原

【Abstract】 [Objective] A real long-span hybrid continuous beam bridge was taken as the study case. This study investigated the load transfer mechanism and structural parameters of steel-concrete composite segment of hybrid continuous beam bridge, providing theoretical basis for bridge structural safety improvement and refined design. [Method]A refined finite element model of steel-concrete composite segment was developed with Abaqus for static analysis. The characteristics of load transfer along bridge direction were investigated. The axial force bearing ratio of concrete and steel components were clarified by using the method of stress integration. The load transfer mechanism of steel-concrete composite segment of such hybrid continuous beam bridge was revealed. The influences of different structural parameters on load transfer were investigated. According to the comparative analysis on calculation results, the specific values of various parameters were suggested. [Result] The critical stress concentrations occur at the pressure-bearing plate and the transition zone between joint segment and concrete girder. The reason is that the load transfer is initially borne by the steel component alone; then changes to the synergistic bearing of steel room and concrete of joint section; and finally transforms into the concrete beam transition section bearing alone. The steel transition segment effectively distributes loads to the pressure-bearing plate, which carries 57.38% of axial forces, but shows stress concentrations at steel joints. [Conclusion] The pressure-bearing plate thickness should be controlled within 50-70 mm. The top and bottom plate thickness should be controlled within 20-28 mm. The concrete strength grade of C50-C60 is reasonable.更多还原