带槽孔预制桥面板预应力筋张拉合理顺序分析

Analysis of Reasonable Prestressed Tension Sequence of Prefabricated Bridge Slab with Trough

为了研究组合梁桥带槽孔预制混凝土桥面板横向预应力筋的张拉方式对桥面板应力情况的影响,结合某具体工程,采用有限元方法建立预制板模型,计算分析了不同预应力筋张拉方法下混凝土桥面板的受力情况.计算结果表明:桥面板的受力情况和先张拉的预应力呈线性关系;但由于预制板中有剪力钉槽口的存在,在张拉预应力筋时会引起槽口处的应力集中现象.分析对比得出推荐施工方案为:先一次张拉未经槽口处的预应力筋,待桥面板与钢梁连成整体时再一次张拉剩余预应力筋,这样可以有效减小该处的应力集中现象,提高预应力筋工作效率,且施工工序简单.

In order to study the influence of transverse prestressed tendons'tension sequence on the stress of composite beam bridge deck with the trough hole,this paper establishes the model of prefabricated slab by finite element method,and analyses the stress of concrete bridge deck under different prestressed tendon sequences.The results show that the stress of the bridge deck is linearly related to the pre-tensioned force,but due to the existence of shear studs grooves in the prefabricated slabs,the stress concentration will occur when the prestressed tendons are tensioned.Through analysis and comparison,the recommended construction scheme is to pull the prestressed tendons that have not passed through the notch to the control stress at one time firstly,and pull the remaining prestressed tendons when the bridge deck and steel beam are integrated secondly.The stress concentration phenomenon can be reduced,also the working efficiency of the prestressed tendon can be improved and the construction process is simple in this way.