FRACTAL STUDY ON THE REPRESENTATIVE ELEMENTARY VOLUME OF JOINTED ROCK MASSES

The scale effects of the jointed rock masses are the external behaviors of the inherent complexity of the structure,and could be attributed to the fracture network inside. The paper determines representative elementary volume on the basis of the evaluation of statistical homogeneity of rock mass structure. The study shows that the rock masses structure has statistical self-similarity,and the fractal dimension of the rock structure decreases with the size of the specimen increasing; but when the specimen dimension increases to a certain value,the fractal dimension varies no more. This certain value is named the structural representative elementary volume (SREV). That’s to say,once the size of the specimen reaches SREV,then it is representative of the structure of the homogeneity. According to the definition of REV,only when the size of the specimen reaches REV,is the mechanical behavior of the rock mass representative. Because the similarity of structure is the prerequisite of the similarity of mechanical behavior,this means the SREV must be the lower bound of REV.