Abstract: The monitoring of subway tunnels in China mainly uses the traditional measurement based on the total station. The monitoring points are limited and the monitoring process is slow. It is difficult to fully reflect the deformation of the tunnel structure. Aiming at the structural characteristics of subway tunnels, this paper proposes a tunnel structure monitoring scheme based on a new mobile 3D laser measurement technology. Firstly, the mobile laser scanning is used to obtain high-density point cloud data, and then the ring stitching seams at the top of the tunnel are automatically identified and extracted. Based on the point cloud data, the ring segment surface information is extracted and the ring slice structure is analyzed. Finally, The comprehensive data management platform is used to conduct management analysis on various monitoring results to achieve scientific management of tunnel structure changes. The actual engineering application shows that the scheme's monitoring results are accurate, the results analysis and management are more scientific, and it meets the needs of tunnel health monitoring.

Key words: tunnel monitoring, total station, mobile 3D laser, point cloud data analysis, data integrated management system