Surrounding rockcataloging of underground caverns based on laser point cloud and panoramic imagetechnology—— taking the Yangtze-to-Han river diversion project as an example

The handheld 3D laser scanner based on SLAM technology can quickly obtain 3D point cloud data in underground caverns, foundation pits and other environments, and can complement each other with panoramic images and better serve the geological cataloging work. Based on the research on the data characteristics of handheld laser scanners, this paper summarizes the technical methods such as panoramic image and 3D point cloud fusion matching, production surveying, and geological catalog map generation. Using C++ language and Qt framework, the panoramic 3D geological catalog software has been developed, so that geologists can perform geological cataloging under the panoramic view on the PC side, and quickly export geological catalog maps and geological information attribute tables. In field tests, we verified that the laser point cloud and panoramic images are well matched to meet the needs of panoramic geological cataloging. By comparing with the measured data, the error of production condition measurement is basically within 3~6°, which belongs to the acceptable range of engineering, which verifies the reliability of this technology in the measurement of geological elements. For underground caverns, geological catalogs can be made with panoramic imagery and projected exports to generate geological cataloged maps as 2D vector graphics. This study provides an efficient and accurate data acquisition and analysis tool for underground engineering geological survey, which reduces the working time of geologists in the underground cavern construction site, improves work efficiency and reduces safety risks.