摘要
常泰长江大桥主航道桥为主跨1208 m的公铁两用钢桁梁斜拉桥,桥塔设计总高350 m,为钢-混混合空间钻石型桥塔,中、下塔柱为四塔肢结构,单塔肢为正八边形截面。针对5号桥塔施工测量难点,布设专用测量控制网,设置桥塔外形几何特征点;在相邻塔肢顶面设置全站仪完成下塔柱劲性骨架和中塔柱钢筋部品安装定位后,采用外控法在桥塔最稳定状态以塔下控制点为基准,基于全站仪三维坐标法对距离进行投影改正后将塔下测量基准引测到塔顶,采用内控法以桥塔中性位置的塔顶测站点为基准,设置全站仪远距离定向后对桥塔相对几何尺寸进行测控;采用高精度全站仪单向三角高程差分修正法和天顶测距高程基准传递法实施桥塔高程控制;基于塔身监测棱镜监测桥塔空间姿态变化和日照位移变形规律,并采用超长线路静力水准自动化监测技术实施桥塔基础沉降的长期监测。该施工测量技术实现了四塔肢桥塔空间姿态误差不超过±8 mm,桥塔垂直度不超过1/8000的质量控制目标。
The main navigational channel bridge of Changtai Changjiang River Bridge is a cable-stayed bridge with a main span length 1208 m.The superstructure consists of steel trusses that accommodate both road and rail traffic.The two pylons with a design height of 350 m,are steel-concrete hybrid,spatial diamond-shaped structures,each containing four columns of octagonal cross-section,and the four columns merge to be a single top column that carries the anchorages of the stay cables.A specialist measurement control network was established for the pylon No.5,to determine the geometric feature points of the pylon.To install the stiffening skeleton of the lower pylon columns and the reinforcement in the intermediate pylon columns,a total station was installed on the top of the adjacent pylon column for positioning control.An external control method was employed,at the most stable state of the pylon,taking the control points under the pylon as measurement reference,a 3D coordinate method of total station was utilized to correct the projection of the distance first,and then the measurement reference under the pylon was introduced to the pylon top.Afterwards,an internal control method was used to control the relative dimension of the pylon after setting the long-distance directions.The elevations of the pylon were controlled by the high-precision total station one-way triangulation elevation difference correction method and the zenith distance elevation datum transfer method.The spatial position variation and sunshine displacement deformation law of the pylon was monitored via the monitoring prisms.and the long-term monitoring of the pylon foundation settlement is implemented through the ultra-long line static leveling automation monitoring technology.By using the presented construction measurement technology,the spatial posture error of the four-column does not exceed±8 mm,and the perpendicularity of the pylon does not exceed 1/8000.
作者
解光路
刘建
詹益
XIE Guanglu;LIU Jian;ZHAN Yi(CCCC SHEC Fourth Engineering Company Ltd.,Wuhu 241060,China)
出处
《世界桥梁》
北大核心
2025年第1期49-55,共7页
World Bridges
基金
江苏省交通运输厅科技项目(CT-SGZT-16)。
关键词
斜拉桥
空间钻石型桥塔
四塔肢
空间姿态
位移
施工测量
自动化监测
cable-stayed bridge
spatial diamond-shaped bridge pylon
four-column pylon
spatial posture
displacement
construction measurement
automated monitoring
