合龙为桥梁由静定转换为超静定的关键工序，其措施、参数的确定对施工过程及后期运营结构安全有着较大影响。文中以82．5 m＋90 m＋220 m＋82．5 m 的北盘江大桥合龙为对象，对超大跨径桥梁多次体系转换的合龙技术进行了研究，结合桥梁后期收缩、徐变引起的墩身水平位移计算成果，以各墩弯矩平衡为原则，确定了顶推力、顶推量、合龙温度等参数，制定了合龙段配重、顶推、锁定、浇筑等合龙工序，保证了施工过程及成桥状态下的结构安全。%Closure is a key construction step by which a bridge transforms from a statically determinate structure to a statically indeterminate one.The measures and parameters adopted will exert considera-ble influence on the construction process as well as the structural safety in the late service period.For this study,the Beipanjiang River Bridge with span arrangement of 82.5 m+220 m+290 m+220 m+82.5 m was taken as the study background.The closure techniques led the long-span bridge to experi-ence multiple systematic transformations were studied in depth.Combined with the calculated values of pier shaft horizontal displacement induced by the late shrinkage and creep of the bridge,a series of parameters,such as the pushing force,pushing amount and closure temperature,were rationally de-termined in the context that the bending moments in piers were in balance.And the closure steps in-cluding the closure section counterweight,jacking and pushing,closure gap locking and concreting were formulated,aiming to assure the safety of the structure during the construction process and in the completed bridge state.
展开▼
