预应力箱梁桥开裂成因研究

文章编号:(201602-0041-03

预应力箱梁桥开裂成因研究

张铁虎

(西安公路研究院,陕西 西安  710065

  要:开裂现象是预应力箱梁桥的主要病害,影响到桥梁的工作性能,本文通过对预应力小箱梁在施工期间预应力的偏位及预应力偏位与超张拉综合作用是否会导致箱梁底板产生纵向裂缝进行了仿真计算,对不同预应力偏位程度及超张拉多种分析工况进行计算分析,得出钢束偏位与超张拉对底板纵向开裂影响程度很小。因此,引起箱梁开裂的因素更有可能是钢筋缺失或混凝土不密实,张拉钢束时混凝土强度较低及保护层厚度不足。

关键词:桥梁工程预应力小箱梁裂缝成因

中图分类号U441          文献标识码A

Study on Cracking of Prestressed Box Girder Bridge

ZHANG Tie-hu

Xi’an Highway Research InstituteXi'an 710065China

AbstractCracking phenomenon is the main disease of prestressed box girder bridge, which affects the  working performance of the bridge. Whether the deflection of prestressed deviation and the combined action of prestressed deviation and super tension could lead to longitudinal cracks in the bottom slab during prestressed box girder construction period was simulated in this paper, and various analysis cases of different prestressed deviation and extra tension were calculated and analyzed.The results showed that the influence of prestressed deviation and extra tension to bottom longitudinal cracking was very small. Therefore, the factors of box girder cracking are more likely to be lack of reinforcement or less dense concrete, low strength concrete in tensioning steel beam and less than the thickness of the protective layer.

Key wordsbridge engineeringprestressed box girdercrackorigin