Abstract
It is well known that the behavior of discontinuous rock masses is strongly influenced by the properties of discontinuities distributed in rock masses. Those are the conditions of geometrical distribution and mechanical properties of discontinuities. This paper deals with the mechanical properties of discontinuities. The mechanical properties of them, basically, should be obtained by laboratory and/or in-situ shear tests, and then those properties can be determined. However, the test results vary from the size of specimens used, what is called scale effect. The persistence of discontinuities in the real rock masses is from tens centimeter to tens meter. Since, in order to estimate the actual behavior of rock masses using test results, it is required to consider the influence of scale effect. This paper describes the comprehensive review about the researches up to now concerning the scale effect of discontinuities and suggests the practical determination method of shear stiffness, shear strength, dilation and normal stiffness to be used for the analysis of rock masses behavior.
