不中断交通下既有桥梁墩柱置换技术  

Techniques to Replace Piers of Existing Bridge Without Traffic Disruption

作　　者：杨勇 禹猛 YANG Yong;YU Meng(Poly Changda Engineering Co.,Ltd.,Guangzhou 510620,China)

机构地区：[1]保利长大工程有限公司,广东广州510620

出　　处：《世界桥梁》2024年第4期122-127,共6页World Bridges

基　　金：保利长大工程有限公司科技项目(RD21-01-008)。

摘　　要：广东中江高速公路扩建主线路基下穿四村立交C、E匝道桥,两匝道桥各有1个桥墩(C18号墩、E12号墩)位于下穿高速公路扩建的主线路基上,需对该2个桥墩进行置换,为下穿高速公路扩建主线路基提供建设空间。既有2个桥墩均为圆柱式双柱墩,且均为上部前、后两联连续箱梁的交接墩。考虑扩建路基空间需要及既有桥梁结构安全,在不中断交通的条件下,分别采用普通大跨径横梁和隐形横梁的门架墩置换原桥墩,并分析墩柱置换施工对匝道桥主梁受力的影响,结果表明墩柱置换后桥梁结构仍满足承载要求。置换施工时,先施工新建置换墩,待新建置换墩具备承载能力后,再切除既有桥墩,实现体系转换。为降低墩柱置换施工对桥梁运营的影响以及减少体系转换次数,C18号墩门架墩横梁包围既有桥墩立柱上部;E12号墩门架墩隐形横梁与上部主梁固结,并在伸缩缝两侧分别单独设置门架墩。The expanded subgrade of the main line of Zhongshan-Jiangmen Expressway in Guangdong Province has sections underpassing the C and E ramps of the Sicun Interchange.The piers C18 and E12,each consisting of two circular columns,served as the transition piers and stood in the way of the expanded subgrade,which had to be replaced to leave space for the construction of the subgrade.To ensure the structural safety of the existing bridge,the original two two-column piers were replaced to be a portal-frame pier with a long cap beams and a portal-frame pier with a concealed cap beam,respectively.The influence of pier replacement on the load bearing behaviors of the ramps was analyzed.It is shown that the load bearing performance of the ramps after pier replacement still meet the requirements.During replacement,the new piers were constructed first,once gaining the required load bearing capacity,the existing piers were cut off,and the system transformation ensued.To reduce the influence of pier replacement on the service of the existing ramps and ease the system transformation,the cap beam of the pier C18 were set to enclose the head of the existing pier columns,while the concealed cap beam of pier E12 was fixed with the deck,with independent portal-frame piers at the two sides of the expansion joint.

关 键 词：桥梁工程 墩柱置换 不中断交通 门架墩 大跨径横梁 受力分析 施工技术 

分 类 号：U443.22[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]