摘要
随着服役年限的增长,大跨径预应力混凝土连续梁桥会出现腹板开裂和跨中下挠等问题。针对既有大跨预应力混凝土连续梁桥的损伤问题,以一座三跨连续梁桥为研究对象,分析其应用矮塔斜拉体系加固前后的受力状态。通过有限元模拟对比加固前后桥梁的应力分布及挠度变化,探讨加固方案的整体加固效果以及塔梁锚固区和索塔锚固区的局部受力状态。结果显示,应用矮塔斜拉体系加固方案后跨中下挠由72.61 mm改善为22.25 mm,主梁由部分截面受拉变为全截面受压。加固后横隔板、箱梁顶板等锚固区域整体应力分布合理,极小范围存在应力集中现象、可采用加强措施。验证了矮塔斜拉体系加固方法的可行性。
As the service life of large-span prestressed concrete continuous girder bridges increases,issues such as web cracking and mid-span deflection often arise.To address these problems,this study focuses on a three-span continuous girder bridge,examining its stress state before and after strengthening with a low-tower cable-stayed system.Using finite element simulations,the bridge's stress distribution and deflection were compared between pre-and post-strengthening conditions,thereby assessing the overall effectiveness of the strengthening scheme and the local stress state in both the tower-girder anchorage and the pylon anchorage zones.The results indicate that,after applying the low-tower cable-stayed system,the mid-span deflection decreased from 72.61 mm to 22.25 mm,and the main girder transitioned from partially tensile sections to fully compressive sections.Following reinforcement,the overall stress distribution in anchorage regions(such as diaphragms and box girder top slabs)remained reasonable;only a very limited area exhibited stress concentrations,which can be mitigated by additional reinforcement measures.These findings verify the feasibility of the low-tower cable-stayed system as a strengthening method for existing continuous girder bridges.
作者
代天宇
覃清玥
张文学
许乐
DAI Tianyu;QIN Qingyue;ZHANG Wenxue;XU Le(College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《国防交通工程与技术》
2025年第1期36-40,91,共6页
Traffic Engineering and Technology for National Defence
关键词
桥梁加固
矮塔斜拉体系
大跨径连续梁桥
局部应力
锚固设计
bridge reinforcement
low-tower cable-stayed system
long-span continuous girder bridge
local stress
anchorage design
