A Multidimensional Clustering Analysis Method for Dividing Rock Mass Homogeneous Regions Based on the Shape Dissimilarity of Trace Maps

Dividing rock mass homogeneous regions according to discontinuities has important engineering significance. This study proposes a multidimensional clustering analysis method for dividing rock mass homogeneous regions based on shape dissimilarities, which reflect the comprehensive properties of discontinuities. The method mainly includes four procedures: (a) division of small trace maps, (b) calculation of shape dissimilarity based on the box-counting dimension and trace angle, (c) construction of the feature vector of a small trace map, (d) multidimensional clustering analysis. The attributes of clustering samples in this method are all shape dissimilarities with dimension = 1, so there is no need to assign weights to the attributes in the clustering analysis, i.e., it is a multiple-factor division method for rock mass homogeneous regions without manual setting of weights. Simulation experiments are used to validate the method, and the results show that this method is effective. In addition, some limiting conditions and test method about division results are discussed. Finally, a rock exposure at a hydropower station dam is used as a case study to illustrate the utility of the proposed method. The proposed method is believed to be a potentially useful tool for studying the spatial variability of geometric parameters of rock masses.