常泰长江大桥桥塔空间纵横梁施工控制

Construction Control of Spatial Longitudinal and Transverse Girders of Changtai Yangtze River Bridge Tower

常泰长江大桥主航道桥为在建世界最大跨度斜拉桥,首次采用钢-混混合结构空间钻石形桥塔。因桥塔特殊的结构形式和力学行为,在设计阶段对其施工控制方案进行分析,针对施工期可能存在的问题进行优化设计。结果表明:纵横梁施工控制方案对桥塔控制断面内力、塔底反力、纵横梁线形及预应力布置均有影响。区别于传统桥塔下横梁不参与纵向整体受力,该桥塔下横梁(纵梁)通过塔梁节点转动参与主塔纵桥向受力。通过建立桥塔有限元模型,基于设计阶段纵横梁的受力特点提出施工控制措施,最终保证了纵横梁施工期的结构安全,实现了对结构线形的高精度控制。

The main channel bridge of Changtai Yangtze River Bridge is the world’s longest span cable-stayed bridge under construction,and for the first time,it adopts a steel concrete mixed structure spatial diamond-shaped bridge tower.Due to the unique structural form and mechanical behavior of the bridge tower,the construction control plan will be analyzed during the design phase to optimize the design for potential construction period issues.The results indicate that the construction control plan for longitudinal and transverse girders has an impact on the internal force of the bridge tower control section,tower bottom reaction force,longitudinal and transverse girder alignment,and prestressed arrangement.Unlike traditional bridge towers where the lower transverse girder does not participate in the overall longitudinal force,the longitudinal girder of the bridge tower lower transverse girder participates in the longitudinal force of the main tower through the rotation of the tower girder nodes.By establishing a finite element model of the bridge tower,analyzing the stress characteristics of the longitudinal and transverse girders during the design phase,and proposing construction control measures,the structural safety of the longitudinal and transverse girders during the construction period was ultimately ensured,and high-precision control of the structural alignment was achieved.