Meticulous three-dimensional demarcation and separate presentation of statistically homogeneous structural domains within a large-scale jointed rock mass

Abstract

Traditional methods used to demarcate homogeneous structural domains are mainly concerned with small-scale discontinuities; this approach can be regarded as a process for evaluating the degree of homogeneity among stochastic discontinuities from one site to another. This process forms the basis for determining the distribution of stochastic discontinuities within a homogeneous structural domain; however, it neglects large-scale discontinuities. In this study, the statistically homogeneous structural domains within a large-scale jointed rock mass were meticulously demarcated in three dimensions, which was performed in four steps. 1) A three-dimensional discontinuity network model was constructed containing both deterministic and stochastic discontinuities. 2) The model was subsequently discretized into a large number of cubic grids, and the MBi values of all the grids were calculated. 3) Using the K-means algorithm, the structural domain boundaries within the tested rock mass were meticulously demarcated, and a composited model consisting of homogeneous structural domains was constructed. 4) Each homogeneous structural domain was separately visualized. This demarcation method can consider large-scale discontinuities and improve the identification sensitivity in a large-scale jointed rock mass with a high accuracy. Moreover, the separate presentation of structural domains directly reflects the morphological properties unique to each structural domain.