Numerical Investigations on the Blockiness of Fractured Rocks

Some of the modern models treat rock masses as assemblages of the isolated blocks while most of the others treat rocks as continuum materials. It is a question that at what a level rocks really are assemblages of isolated blocks. This paper presents a parameter (B) to measure the degree of rocks to resemble the assemblages of blocks. The parameter is a dimensionless number between 0.0 and 1.0, and is defined as the ratio of the aggregated volume of the individual blocks in the investigated domain to the total volume of the investigated domain. ISRM presents a quantitative description scheme for fracture spacing and persistence, where fracture spacing is divided into 7 and persistence is divided into 5 ratings. Different fractured rocks are constructed to perform blockiness investigations. In this paper, seventy-seven fractured rock types are constructed. Their fractures cover all the ratings of fracture spacing and persistence suggested by ISRM. Based on blockiness results of these 77 rock types, an analytical solution is obtained to describe the relationship between blockiness and fracture spacing and persistence by fitting the blockiness results.