U型梁预应力筋张拉次序对受力性能影响的有限元分析

The finite element analysis on tensile sequence of U-beam prestressed reinforcement

随着现代预应力技术的发展,预应力混凝土在土木工程中应用越来越广泛,特别是在大跨度的建筑结构及桥梁结构中[1],而预应力张拉工艺又是影响预应力混凝土构件力学性能的重要环节。为考察预应力张拉次序对混凝土体的影响,以青岛蓝色硅谷城际轨道交通工程07标段的现浇三跨连续U型薄壁梁为工程背景,利用Midas civil软件建立有限元分析模型,结合实际施工情况,提出几种典型的预应力钢束张拉方案,在该理论分析模型上进行模拟张拉,通过比较这几种不同张拉次序下结构的反应,提出弯箱梁桥预应力钢束较合理的张拉顺序[2]。

With the development of modern prestressing technology,the application of prestressed concrete in civil engineering is more and more widespread,especially in the long-span structure and bridge structure,and the prestressed tensile process is an important link to influence the mechanical properties of prestressed concrete members. In order to investigate the influence of prestressed tensioning order on the concrete body,this paper takes the cast-in-place U beam of three span continuous U thin-walled beam in the 07 section of the intercity rail transit project in Qingdao as the engineering background. The finite element analysis model is established by Midas civil software,and several typical prestressed steel beam tensioning schemes are put forward in combination with the actual construction situation. By comparing the reactions of these different tensile orders( structural stress,deformation,etc.),the more reasonable tensioning order of the prestressed steel beam in the curved box girder bridge is put forward.