大斜交角连续多箱室钢-混凝土组合梁设计研究

Study on Design of Continuous Multi-box Steel-concrete Composite Girder with Large Oblique Angle

摘要:

为探究大斜交角连续多箱室钢-混凝土组合梁设计细节，以某45°大角度斜交连续钢-混凝土组合梁为例，通过桥梁博士软件建立不同横梁布置下的梁格法模型，对比不同横梁布置方式对结构弯矩及支反力的影响；同时为验证设计中常用的单梁简化建模的有效性，建立单梁模型与梁格模型进行对比。结果表明：横梁正置或斜置对斜交桥影响较小，为便于标准化制造，推荐中支点横梁采用正置；内力若采用单梁法简化计算，误差有10%以上，需考虑该误差影响。对于大角度斜交桥梁，单梁计算所得反力误差较大，推荐采用梁格法进行计算。最后，给出斜交连续钢-混凝土组合梁负反力处理方式及桥面板钢筋的细部构造，为同类桥梁的设计提供参考。

Abstract:

In order to study the design details of continuous multi-box steel-concrete composite girder with large oblique angle, taking a continuous steel-concrete composite girder with 45⁰-large oblique angle as an example, the beam grid method model under different beam arrangements is established through the Bridge Doctor software to compare the effects of different arrangement of beams on the bending moment and reaction force of the structure. At the same time, to verify the effectiveness of the commonly used single-beam simplified modeling in the design, a single-beam model is established to compare with the beam-grid model. The result shows that whether the crossbeam is placed upright or inclined has a relatively small impact on the oblique bridge. To facilitate the standardized manufacture, it is recommended that the middle support point crossbeam is placed upright. If the internal force is simplified and calculated by the single-beam method, the error is more than 10%, and the influence of this error needs to be taken into account. For large-angle oblique bridges, the reaction force error obtained by single-beam calculation is relatively large. It is recommended to use the beam grid method for calculation. Finally, the treatment method for the negative reaction force of the oblique continuous steel-concrete composite girder and the detailed structure of the bridge deck reinforcement are given, which provides the reference for the design of similar bridges.