Visualization of 3D rock mass properties in underground tunnels using extended reality

Abstract

The term extended reality (XR) refers to a family of technologies that cover Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). The main benefit of XR is that it can offer a new viewpoint on the surrounding environment by augmenting it with digital data and visualizations. Recent developments of XR enable its deployment for rock engineering applications, including underground tunnels. In this paper, we demonstrate two cases of the use of XR in an underground tunnel to display spatial information on the tunnel surface. One of the tunnels in the Underground Research Laboratory of Aalto University (URLA) was digitized using Structure-from-motion (SfM) photogrammetry. As a result, a high-resolution 3D point cloud and textured model of the tunnel were created. Next, the rock joint planes were obtained semi-automatically from the digitized rock surfaces. The results are then represented in their actual positions in the tunnel geometry. In the first case, we used VR to display the rock joint planes on the textured model of the tunnel. In the second case, the data was displayed in real-time in tunnel conditions through a mobile device. The results demonstrate that XR technology can be successfully used in underground construction to digitize the workplace and provide a new perspective on the work environment, which can potentially lead to an increase in safety and productivity.

Exploring the Fusion Potentials of Data Visualization and Data Analytics in the Process of Mining Digitalization

“…Data visualisation [17], [22], [24], [25], [31], [54] Data analytics [16], [73], [76]- [80] Single factor analytics, such as rock mass rating, microseismic; Multi-factor analytics, such as rockburst, fall of ground; Semantic analytics, such as geo-hazard discrimination.…”

“…From the visualisation perspective, it is generally developed by utilising 3R techniques, including virtual reality (VR), augmented reality (AR), and mixed reality (MR), and so-called extended reality (XR) [18], [20], [21]. However, due to the low data utilisation, visualisation-oriented mining education and training applications are still designed with simple interaction and are limited to solid 3D models [17], [22]- [25], in which the solid model is manually generated from complex 2D DXF/DWG drawings. Given that, data-driven parametric modelling de-velopment receiving more attention in recent visualisation development [26]- [31].…”

Rapid Photogrammetry with a 360-Degree Camera for Tunnel Mapping

“…By adding additional high-resolution images captured in a relatively short time, the total capture time stays much shorter than the conventional method presented in [17] but the model achieves much better visual quality. The improved visual quality is especially important if the model will be used for rock mass characterization, in which some parameters of the rock are assessed visually [28], or if the model will be used for VR/AR-based rock mass mapping systems [28][29][30][31][32]. For this purpose, 13 high-resolution images of the unsupported tunnel wall were captured (Figure 4a) with a Canon 5Ds R full-frame DSLR camera and Canon EF 35 mm f/1.4 L II USM prime lens (Figure 3c).…”

Method to obtain 3D point clouds of tunnels using smartphone LiDAR and comparison to photogrammetry

“…Structure from Motion (SfM) and 3D ground-based laser scanner [5,6,7] or Terrestrial Laser Scanner (TLS) [8] are among remote sensing techniques which have been employed to scan slopes and underground spaces. TLS uses the Light Detection and Ranging (LiDAR) instrument.…”