铁路PC箱梁顶板修复施工优化研究

Study on Construction Optimization of Repairing in Upper Plate of Railway Prestressed Concrete Box Girder

某铁路PC连续箱梁桥在施工过程中,边跨顶板在架桥机支点局部荷载作用下发生破坏,经现场检测及分析后采用凿除顶板损伤部位混凝土并重新浇筑顶板的方法进行加固。首先利用有限元法对顶板损伤成因进行了分析,然后针对提出的加固方法,对加固施工过程进行了优化分析,以保证在加固施工期间结构的安全性。理论分析以及加固施工监测表明,采用分块凿除、分部浇筑方法可以避免加固过程中箱梁底板发生开裂。

In the process of construction of a railway continuous box girder bridge,the upper plate of box girder in side span is destroyed due to the local load of the bridge machine＇s fulcrum. The strengthening method is firstly to chisel the damaged concrete and then pour a new roof,which is adopted after field detection and analysis. In this paper,the reason of damage is analyzed by finite element method at first,and then the optimization of strengthening construction is proposed according to the strengthening method mentioned above,which can guarantee security during construction period. Theoretical analysis and construction monitoring show that the method chiseling block by block and pouring part by part proposed in this paper can avoid cracking in bottom plate of the box girder.