GEOLOGICAL AND GEOMECHANICAL DIFFERENTIATION OF ROCK INTERFACES BASED ON RECURSIVE MULTI-SCALE ANALYSIS WITH TOPOGRAPHICAL DATA SETS

ABSTRACT: Proper geomechanical description of natural or engineered excavations promote reliable description of instability potential and informative notions related to geological units’ structures and geometry. Rock mass features present different geomechanical properties which highlight crucial information such as rock or slope instability indicators, failure mechanisms, evaluation of geohazard phenomenon, and other engineering purposes. Most of the existing methods for differentiating geological units are either geometry driven (e.g., differentiation based on joint set orientations) or are empirical to human visual discrimination. This article presents a remote-sensing assisted method for differentiating, describing, and quantifying geomechanical conditions and geological units along exposed rock outcrops. The presented methodology is based on topographical characterization of rock surfaces from 3-dimensional digital surface models captured with remote sensing tools. A fractal-based approach is utilized as a framework for geomechanical differentiation of geological features. An initial recursive roughness-based analysis is performed to quantify scale-dependency along the inspected rock outcrop. A second layer of recursive analysis is performed for small moving spherical neighborhoods generated on the scan. Data sets from an underground tunnel wall are identified and subdivided with respect to known geological units. Back analysis of the known topographical characteristics for different geological regions is performed to evaluate the differences in terms of fractal components.