混凝土箱梁桥的预应力钢板加固技术  

Prestressed Steel-plate Reinforcement Technology of Concrete Box Girder Bridge

作　　者：王泽宁 Wang Zening(Beijing General Municipal Engineering Design&Research Institute Co.,Ltd.,Beijing 100082,China;Beijing Engineering Research Center of Urban Bridge Security,Beijing 100082,China)

机构地区：[1]北京市市政工程设计研究总院有限公司,北京100082 [2]北京市城市桥梁安全保障工程技术研究中心,北京100082

出　　处：《市政技术》2022年第11期136-142,共7页Journal of Municipal Technology

摘　　要：近年来,随着我国城市建设不断精细化,市政基础设施建设也越来越复杂,导致一般新建工程施工对既有市政设施产生了一定的影响,特别是对一些相邻的老旧交通设施影响较大。基于此,阐述了一则地下工程施工对相邻桥梁产生较大影响的案例。该案例在现有预应力混凝土箱梁桥的预应力损失和墩柱差异沉降的影响下,出现了混凝土箱梁开裂和梁体下挠病害,直接影响到桥梁的运营安全,同时导致桥下净空受到限制,故建议采用预应力钢板加固的方法解决桥梁病害。具体措施为:利用锚栓和粘钢胶将加固的钢板固定在箱梁底板,通过施加预紧力和桥梁顶升技术将预应力施加在加固钢板上,使预应力钢板与加固后的主梁共同受力,从而达到桥梁维修加固的目的。采用该种维修加固方法,既恢复了一部分预应力混凝土箱梁的刚度,又改善了主梁下缘的应力状态,是一种有效的桥梁维修加固方法,可为类似工程的处理提供借鉴。With the continuous refinement of urban construction in China,the construction of municipal infrastructure is becoming more and more complex.Generally,the construction of new projects will have some impact on existing municipal facilities,especially some adjacent old traffic facilities.This paper expounds a case that a underground engineering has a great impact on an adjacent bridge.Under the influence of prestress loss and differential settlement of pier column,the concrete box girder cracking and diseases of beam down deflection directly affect the operation safety of the bridge.Due to the limitation of the clearance under the bridge,reinforcement by the prestressed steelplate is adopted to solve the bridge diseases.The specific measures are fixing the reinforced steel plate on the bottom plate of the box girder with anchor bolts and steel glue.The prestress is applied to the reinforced steel plate by preload and the bridge beam jacking technology to make the prestressed steel-plate and the strengthened main beam bear the same force and achieve maintenance and reinforcement of the bridge.This method can not only restore the stiffness of some prestressed concrete box girders,but also improve the stress state of the lower edge of the main beam.It is an effective bridge maintenance and reinforcement method which can provide reference for the treatment of similar projects.

关 键 词：预应力混凝土箱梁 箱梁开裂 梁体下挠 预应力钢板 维修加固 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]