How to determine the appropriate methods to identify the geometry of in situ rock blocks in dimension stones

Abstract

The present article reviews various methods for discontinuity and rock block survey. The variety of techniques to determine the shape and size distribution of the rock blocks were divided into index and modeling methods. The index methods calculate the average size of a rock block as a representative of the rock mass. These methods are simple, cheap and fast, but are associated with large errors because of the presence of the rock mass of rock blocks with different geometries. Hence, index methods are not recommended. In modeling techniques, discontinuity surveys try to model the rock mass realistically to determine the geometry of all blocks with different algorithms. These methods also have some defects in modeling the discontinuities and calculating the geometry of blocks. In order to perform an evaluation of all methods, six conditions were identified to determine the method for surveying rock blocks. The conditions include the ability to model random discontinuities and joint sets with specific dimensions, the inability to simulate discontinuities with statistical methods (the ability to study a discontinuity network separately), determining the geometry of all rock blocks, considering the dangling and isolated discontinuities, simplicity, and three-dimensionality. Based on the above requirements, a new approach is proposed to determine suitable methods for use in the evaluation of dimension stones. This new methodology was applied in a limestone quarry in Joshqan, Iran, to verify the applicability of the different methods in dimension stone quarries.