Development of the new tunnel face observation method using 3-D point clouds and virtual reality

Abstract

This article summarizes the results of development based on the recent studies (Kojima et al., 2024a, b). On-site observation of excavated tunnel faces is difficult due to safety regulations and a shortage of geological experts. Although several tools have been proposed for remotely observing the face with photographs or videos, they do not provide three-dimensional (3-D) realistic observations and measurements. We developed a new method to solve this problem, using a 3-D point cloud and a virtual reality (VR) system. This method allows to examine a tunnel face in detail remotely. We validated the effectiveness of this new method by comparing it to a conventional on-site method by visual inspection in a tunnel where talus deposits are distributed. The VR method revealed the detailed distribution and geological structures of the talus at the tunnel crown, whereas the conventional method could not. These results show that the VR method could be an effective solution to this problem.