斜拉桥塔梁固结区预应力布索方式对比分析

Comparative Analysis of Prestressed Bundle Arrangement in the Tower-girder Consolidation Zone of Cable-stayed Bridge

针对斜拉桥塔梁固结区受力复杂的问题,首先通过有限元模拟分析结构的应力云图,对塔梁固结区提出基于拉压杆模型的设计计算方法。其次以某斜拉桥为背景,分别对不同工况下塔梁固结区的横梁底板、顶板和腹板进行有限元分析,最后在分析张拉横向预应力束对塔梁固结处横梁应力影响的基础上,进一步探究依据拉压杆模型调整预应力布索方式对塔梁固结区应力状态的优化效果。结果表明,依据拉压杆模型调整预应力束线形,可以在满足预应力储备的条件下,降低塔梁固结区顶部、底部和腹板的局部拉应力,尤其是底部的拉应力。

Aiming at the problem of complex stress in the tower-girder consolidation zone of cable-stayed bridge,this paper firstly analyzes the stress nephogram of the structure through finite element simulation,and puts forward the design and calculation method of the tower-girder consolidation zone based on tension compression bar model.Secondly,taking a cable-stayed bridge as the background,the finite element analysis of the girder bottom plate,top plate and web in the tower-girder consolidation zone under different working conditions is carried out.Finally,Based on the analysis of the influence of tensioning transverse prestressed bundle on the stress of the girder at the tower-girder consolidation place,the optimization effect of adjusting the prestressed bundle arrangement mode according to the tension and compression bar model on the stress state of the tower-girder consolidation zone is explored.The results show that adjusting the prestressed bundle pattern according to the strut-and-tie model can reduce the local tensile stress at the top,bottom and web of the tower-girder consolidation zone,especially at the bottom,while satisfying the prestress reserve.