小半径节段拼装箱梁预应力效应研究

Research on Prestressing Effect of Small-radius Segmental Assembled Box Girder

摘要:

依托深圳新城立交工程，以跨径3×32.5 m、宽9 m的匝道桥节段梁为例，建立了空间杆系及实体有限元模型，对小半径节段箱梁的预应力效应进行了研究。分析了在小半径节段箱梁中，钢束对主梁的有效内力和次内力随曲线半径的变化规律、不同钢束类型和钢束位置对主梁次内力的影响及体外束对主梁顶底板、转向块和限位块局部应力的影响，并结合分析结果提出了关于小半径节段箱梁钢束合理布置的方案建议。

Abstract:

Relying on the Shenzhen Xincheng Interchange Project, taking its ramp bridge segmental beam with 3×3.5 m span and 9 m width as an example, the spatial rod system and solid finite element model is established to study the prestressing effect of small-radius segmental box girder. In the small-radius segmented box girder, the variation laws of the effective internal force and secondary internal force of the steel bundle on the girder with the radius of the curve, the influence of different types and positions of the steel bundle on the secondary internal force of the girder, and the influence of the external bundle on the local stress of the top and bottom plates, the steering block and the limit block of the girder are analyzed. And combined with the analysis result, the suggestions on the reasonable layout scheme of steel bundles for small-radius segmental box girders are put forward.