预制小箱梁简支转连续施工期力学响应研究

Research on Mechanical Response of Precast Small Box Girder from Simple Support to Continuous Construction

文章以宜兴至长兴高速公路YC-YX2标段楼下大桥左线5×25 m联为工程背景,采用光纤光栅传感器(FBG)及振弦式应变传感器进行联合监测,围绕预制混凝土小箱梁的施工关键阶段进行研究,跟踪各跨主梁顶底板应力在各个施工工况变化规律,分析预应力张拉及落梁阶段的应力变化及稳定时间,提出采取相应的施工控制使结构符合设计要求,确保桥梁后期的正常运营。

This paper takes the 5 ×25 m connection of the left line of the downstairs bridge in the YC-YX2section of the Yixing-Changxing expressway as the engineering background, and uses fiber grating sensors(FBG)and vibrating wire strain sensors for joint monitoring, and surrounds the precast concrete small box girder. To study the key construction technology, track the changes in the top and bottom plate stress of the main beams of each span in various construction conditions, analyze the stress changes and stabilization time of the pre-stressed tensioning and falling beam stages, and adopt corresponding construction controls to make the structure meet the design requirements. Ensure the normal operation of the bridge in the later period.