摘要
为了解决桥梁顶推法施工由于正负弯矩交替出现、预应力筋作用以及顶推装置的影响导致连续梁梁体的开裂问题,以厦深联络线连续梁施工为背景,开展对预应力混凝土连续箱梁顶推施工中结构"零损伤"的研究。借助midas桥梁建模软件,仿真分析连续箱梁在不同的预应力张拉方式下,不同顶推阶段中导梁及箱梁的上下缘应力,并通过实测数据对比,验证仿真分析的可靠性。研究结果表明:(1)在顶推的各个阶段,部分预应力张拉方案较全部预应力张拉方案主梁及导梁的拉压应力均变小;(2)采用预应力部分张拉方案解决了顶推过程中箱梁顶板上沿拉应力超限、预应力处理不当导致的梁体裂缝问题;(3)可采用增加布料孔和振捣孔、定制钢底模、设置沉降差等措施控制混凝土质量,为后续顶推施工箱梁"零损伤"提供条件。
The cracking in continuous beam could be caused in the process of incremental launching construction due to the alternating positive and negative bending moments, action of prestressed reinforcement and incremental launching device. To solve the problem, the research on “zero damage”in incremental launching construction of prestressed concrete continuous beam was carried under the background of Xiamen- Shenzhen tie line project. The upper and lower edge stresses of the guide beam and the box girder in different stages were simulated and analyzed under different pre-stressing tensioning modes by Midas. The reliability of the simulation data was verified through comparing with the measured data. The result shows that at each stage of the incremental launching construction, the tension-compression stress of the main beam and the guiding beam of the partial pre-stressed construction is smaller than that of full pre-stressed construction. The partial pre-stressed construction solves the problem of cracks in the beam body caused by excessive tensile stress and improper prestressing treatment on the top plate of the box girder in the process of incremental launching construction. The measures, such as increasing the hole of pouring material and vibrating, customizing steel bottom mold, setting settlement difference, etc., can control the quality of the concrete and provide conditions for the subsequent “zero damage”of the box girder.
作者
张永刚
Zhang Yonggang(China Railway 19 Bureau Group Fisrt Engineering Co. , Ltd, Liaoyang 111000, China)
出处
《铁道勘察》
2019年第2期37-41,46,共6页
Railway Investigation and Surveying
关键词
混凝土连续箱梁
顶推施工
张拉工艺
零损伤
Concrete continuous box girder
Incremental launching construction
Tension technology
Zero damage
