ABSTRACT
The main cable of the suspension bridge is the main and most important component of the structure. The main cable shape is mainly determined by the horizontal tension of the main cable, the suspension cable force, and its own load concentration. In the completed bridge state, the main cable shape can reflect the cable force of the suspension cable and also reflect its own internal force distribution. Therefore, the true shape of the main cable of the completed bridge is the key to study the stress state of the cable structure of the suspension bridge, which is of great significance to the long-term monitoring of the suspension bridge. In this paper, a method to identify the main cable shape of the suspension bridge based on a 3D point cloud is proposed, and the method is verified against the background of Honghe Bridge in Yunnan Province. The raw point cloud data of main cable was obtained through LiDAR. After noise reduction and registration of the raw data, the main cable point cloud is obtained through clustering algorithm. Then, using the circular tube axis algorithm, the measured central axis of the main cable is obtained. The construction phase of Suspension bridge is analyzed and the main cable model is obtained in the finite element software. Then, the finite element model is exported and registered with the measured point cloud to obtain the theoretical central axis. Finally, the theoretical central axis is compared with the measured central axis to obtain the main cable shape deviation result.
