基于三维激光扫描的钢桁拱桥吊索塔架施工线形监测研究

为确保悬臂拼装钢桁拱桥施工的安全性与精准性,以主跨436 m的中承式钢桁拱桥——广州明珠湾大桥吊索塔架施工为背景,运用三维激光扫描技术对吊索塔架进行多工况线形监测,结合多点位多视角监测与智能点云数据处理,进行吊索塔架垂直度指标计算,并与全站仪测量结果对比.结果表明:三维激光扫描技术可直观表达吊索塔架空间姿态与构造形式,...

Research on 3D Laser Scanning Based Line-Shape Monitoring for Towers of Cable-Stayed Cantilever Assembly System Used in Steel Truss Arch Bridge Construction

In this paper,the Mingzhu Bay Bridge in Guangzhou,which is a half-through steel truss arch bridge,is taken as a case to study the monitoring techniques that can assure the safety and accuracy of the construction of steel truss arch bridge when using a cable-stayed cantilever assembly system.The 3D laser scanning based monitoring technique was applied to monitor the line-shapes of towers of the cable-stayed cantilever assembly system under diverse load cases.Combined with the multi-perspective field monitoring and intelligent point-cloud processing,the perpendicular indexes of the fastening stay towers were computed.The monitoring results were compared with the results monitored by total station.It is shown that the 3D laser scanning can express the spatial posture and configuration of the fastening stay tower visually,and extract its perpendicularity index conveniently.The difference between the perpendicularity indexes of two monitoring methods is mostly limited within±1‰,indicating that the 3D laser scanning results can accurately reflect the actual line-shape of fastening stay towers.And perpendicularity indexes of fastening stay tower line-shape have been controlled within±3‰after the implementation of 3D laser scanning for line-shape monitoring and wind cables tensioning control,indicating that the construction safety met the requirements.