Construction of 3D Model of Tunnel Based on 3D Laser and Tilt Photography

In this study, we take a section of a tunnel located on the expressway as the research subject and propose a 3D model based on high-precision and high-spatial-resolution 3D laser scanning technology to obtain tunnel point cloud data information. The tunnel is built using unmanned aerial vehicle (UAV) tilt photogrammetry technology. The model finally realizes the combination of the 3D visual model of the tunnel and the 3D space around the tunnel. The Trimble TX8 ground 3D laser scanner is used as the tunnel 3D point cloud data acquisition device. Through 3D laser scanning, the collected 3D point cloud is processed by data sampling, thinning filtering, registration, and splicing. With the algorithm of point cloud data to process the fitting and repair of the point cloud, the tunnel information data is effectively acquired and the 3D model is constructed. The construction of a 3D model is completed on the basis of the same phase control points of oblique photography acquisition. The analysis results show that the 3D laser scanning technology has clear effects on the extraction of tunnel spatial data and the construction of the model. The effective combination of 3D laser scanning technology and tilt photography technology has improved the quality of 3D model construction in urban areas and is a major breakthrough in the field of 3D modeling.