An Automatic Data Processing Method for Deformation Analysis and Visualization of Tunnel Cross Sections Using Laser Scanning Data
Based on Laser Scanning Technology (LST), a data processing method is proposed to automatically visualize the tunnel cross sections and collect deformation information. In this method, Cartesian coordinates of each data point are transferred to polar coordinates, and two-dimensional tunnel cross sections can be extracted from three-dimensional point cloud data obtained by LST. The tunnel deformation is calculated by subtracting radius vectors of deformed cross section from design cross section and visualized through adjustable deformation factors. The deformation data at arbitrary azimuthal angles could be gained with an accuracy of 0.1 mm. To achieve the ideal calculation accuracy and ensure visualization performance, a novel algorithm adopting point discretization and regeneration technique is developed to automatically detect and treat the noise and discontinuity points from the point cloud data. While the traditional data processing methods could only handle a specific type of tunnel cross section, the proposed method by us is able to deal with arbitrary shapes of tunnel sections as long as three-dimensional cloud data are available. The results show that the proposed method could provide accurate deformation data with high data processing efficiency for monitoring the deformation of tunnel cross sections in laboratory, and potentially for real-life tunnels.
KeywordsLaser scanning technology Data processing Tunnel cross section
The research was financed by the Natural Science Foundation of China (No. 41372276). The technical support from the staff of Shanghai Tunnel Engineering Co. Ltd. are highly appreciated.
- 3.Clarke, T.A.: A Review of Tunnel Profiling Methods (1996)Google Scholar