预应力混凝土箱梁桥施工中的裂缝成因分析与修补

针对预应力混凝土连续箱梁桥施工过程中箱梁悬臂端底板出现纵向裂缝的现象,在预应力张拉过程中采用光纤传感技术对悬臂端底板受力状态进行实时监测,将监测结果与拆模后的观测情形对比,证明此种监测方法能有效反映混凝土箱梁结构在施工过程中的响应.通过理论分析找出了底板裂缝成因,并利用有限元软件ANSYS对整个施工结构进行数值模拟,得出不考虑混凝土箱梁与外模板之间摩擦作用时箱梁结构的应力、位移值,与实际观测结果比较吻合.最后,采用BICS工法对梁体裂缝进行了修补.

Analysis and Repair of Soleplate Cracks of Pre-stressed Concrete Box Girder During Construction

According to the phenomenon that soleplate cracks at the cantilever of pre-stressed concrete continuous box girder usually appears during construction, monitoring technique with optical fiber is used to monitor the mechanical status of the girder when pre-stressing. The comparison between monitoring result and observations on the spot shows that this kind of monitoring technique is proved to reflect the real response of the box girder during construction effectively.Then, through theoretical analyzing, the cause of cracks is found. Furthermore, the FE software ANSYS is adopted to analyze the whole construction structure, and the stress and displacement of the concrete bridge are gotten without consideration of the friction between the girder and steel mould. Finally, BICS technique is used to repair the cracks of the girder.