南京长江二桥北汊主桥施工的线形控制研究

On Linear-control in Construction of North Branch Bridge of Nanjing No.2 Yang tze River Bridge

以南京长江第二大桥北汊桥主桥施工线形控制实践 ,研究了大跨径预应力混凝土连续箱梁悬浇施工控制体系的构成及其对施工过程的控制 ,阐述了线形控制原理、方法和计算模型 ,并对实时测量的精度及箱梁变形影响因素作了分析 ,给出了修正对策。实时测控系统科学地指导了整个箱梁悬浇施工 ,确保了成桥梁的线形和受力状态与设计的一致 ,取得显著效果 ,有较好应用价值和推广前景。

Through the practice of linear control in construc tion of the north branch bridge of Nanjing No.2 Yangtze River Bridge,the composi tion of big span inherent stress concrete continued box girder Suspension Casti ng system and its controlling over the construction process are studied.The line ar control theory,methods and calculating models are expounded.Based on the ana lysis of the influential elements in precision of real time survey and distorti on of the box girder,modify countermeasures are proposed,while real time surve ying and controlling system used to guide the whole process of the Suspension Ca s ting in order to ensure the linearity and the pressure of the bridge consistentl y with their designed values.