预制混凝土管片快速拼装加固水下桥墩技术研究

发布时间：2018-05-22 18:43

  本文选题：水下桥墩加固 + 预制混凝土管片　； 参考：《东南大学》2015年硕士论文

【摘要】：我国桥梁在飞速发展的过程中,由于其运营时间的增长及交通量与日俱增等原因,各种各样的病害也相继出现,而桥墩是桥梁结构中唯一的抗侧力构件和直接的竖向受力构件,在运营中一旦发生病害将严重限制桥梁相关功能的发挥,甚至由于承载能力不足而导致桥梁结构的倒塌。本文针对当前常被忽视的水下桥墩加固技术进行研究,在总结相应加固技术研究现状的基础上,提出了预制混凝土管片快速拼装加固水下桥墩技术。本文首先对预制混凝土管片快速拼装加固水下桥墩技术进行了室内模拟试验研究,通过对比分析未加固试件、整浇试件与内部无FRP网格的加固试件和内置FRP网格的加固试件的轴压试验结果得出：加固试件的破坏模式得到了显著改善,由脆性破坏变为延性破坏；加固试件的峰值荷载和峰值位移得到了大幅提高,无FRP网格的加固试件和内置FRP网格的加固试件的峰值荷载提高比例为28%和63%,峰值位移提高比例为16%和44%；通过合理的设计,可以使加固试件的综合力学性能接近甚至优于一次性整浇成型的同类试件；影响预制混凝土管片快速拼装加固水下桥墩技术加固效果的关键参数是预制混凝土管片的环向连接性能、水下不分散混凝土强度及环向约束强度。然后,采用ABAQUS有限元分析软件进一步对上述三个关键参数进行定性分析得出：预制混凝土管片环向连接性能将影响结构应力分布和材料强度的发挥程度；水下不分散混凝土强度和环向约束强度对加固结构的峰值荷载影响呈线性相关的关系。在试验研究及ABAQUS有限元模拟的基础上,综合考虑增大截面法及约束混凝土对加固效果的影响,提出了预制混凝土管片快速拼装加固水下桥墩技术的理论计算模型,通过相关文献试验数据的验证发现该模型具有广泛的适用性。最后,以江西北港湖大桥23-4#桩基为依托,进行了预制混凝土管片快速拼装加固水下桥墩技术的试点应用研究,取得了良好的加固效果,并在此基础之上结合试验研究成果总结提出了预制混凝土管片快速拼装加固水下桥墩技术的施工工艺流程和质量控制措施,形成了一套完整的水下结构加固方法,对相关工程的加固设计与施工具有重要的指导意义。
[Abstract]:In the process of rapid development of bridges in our country, due to the increase of operation time and traffic volume, a variety of diseases have appeared one after another, and pier is the only anti-lateral force member and the direct vertical force member in the bridge structure. Once the disease occurs in the operation, the bridge function will be restricted seriously, and even the bridge structure will collapse due to the insufficient bearing capacity. In this paper, the reinforcement technology of underwater pier, which is often neglected at present, is studied. On the basis of summarizing the research status of the corresponding reinforcement technology, the technology of fast assembling precast concrete segment to reinforce underwater pier is put forward. In this paper, first of all, the laboratory simulation test is carried out on the technology of quick assembling and strengthening underwater pier with precast concrete segments, and the unreinforced specimens are compared and analyzed. The results of axial compression tests of the cast-in-situ specimens, the strengthened specimens without FRP mesh and the strengthened specimens with built-in FRP mesh show that the failure mode of the strengthened specimens has been significantly improved, from brittle failure to ductile failure. The peak load and the peak displacement of the strengthened specimens have been greatly increased. The proportion of the peak loads of the strengthened specimens without FRP mesh and that of the strengthened specimens with built-in FRP mesh are 28% and 63%, and the proportion of the peak displacement is 16% and 44% respectively. The comprehensive mechanical properties of the strengthened specimens are close to or even superior to those of the one-off cast-in-place specimens. The key parameters affecting the technical strengthening effect of precast concrete segment are the performance of circumferential connection of precast concrete segment, the strength of underwater non-dispersive concrete and the strength of circumferential restraint. Then, the ABAQUS finite element analysis software is used to analyze the above three key parameters qualitatively. It is concluded that the performance of the precast concrete segment in circumferential connection will affect the stress distribution of the structure and the exertion degree of the material strength; The influence of the strength of underwater non-dispersible concrete and the strength of circumferential confinement on the peak load of reinforced structure is linearly correlated. On the basis of experimental research and ABAQUS finite element simulation, considering the influence of increasing cross-section method and confined concrete on reinforcement effect, a theoretical calculation model of rapid assembly of precast concrete segments for strengthening underwater pier is put forward. It is found that the model has wide applicability through the validation of relevant experimental data. Finally, on the basis of 23-鈪，

本文编号：1923207