Automated detection of discontinuity properties using terrestrial laser scanning data

Ünlüsoy, Deniz
Traditional ground surveying methods for the determination of rock mass discontinuity characteristics are costly and time consuming when large survey areas are involved. In addition, some rock mass surfaces cannot be observed with ground, airborne, or satellite surveying methods. Terrestrial laser scanning offers new avenues in fieldwork, making the acquisition of large amounts of survey data possible. However, there is a need for new approaches and accompanying software for the analysis of such data. In this study, a methodology that uses point cloud data obtained by terrestrial laser scanning is developed and implemented by a software for automated analyses of the physical properties of discontinuities of rock masses. The software processes the point cloud data of the outcrop surface and detects planar structures using density-based scanning on surface normals to determine discontinuity sets. For each set, orientation, spacing, persistence, block size, and roughness are calculated. This study also proposes a novel, simple, accurate, and reliable method for the estimation of joint roughness coefficient from terrestrial laser scanning data using power spectral density. The method is based on the similarity of sample and reference surface profiles by their power spectral density. The accuracy and the reliability of the proposed method is validated by comparison with the classical methods and back-calculated results obtained from the literature. The method is then extended to estimate the JRC of entire surfaces using multiple profiles. This areal JRC estimation method is applied on point cloud data of a rock outcrop for a case study.
Citation Formats
D. Ünlüsoy, “Automated detection of discontinuity properties using terrestrial laser scanning data,” Ph.D. - Doctoral Program, Middle East Technical University, 2020.